LT3061 Series 45V VIN, Micropower, Low Noise, 100mA LDO with Active Output Discharge DESCRIPTION FEATURES n n n n n n n n n n n n n n Input Voltage Range: 1.6V to 45V Output Current: 100mA Output Discharge Quiescent Current: 45A Dropout Voltage: 250mV Low Noise: 30VRMS (10Hz to 100kHz) Adjustable Output (VREF = 600mV) Fixed Output Voltages: 3.3V, 5V Output Tolerance: 2% Over Load, Line, and Temperature Single Capacitor Soft-Starts Reference and Lowers Output Noise Shutdown Current: < 3A Reverse Battery Protection Current Limit Foldback and Thermal Limit Protection 8-Lead 2mm x 3mm DFN and MSOP Packages APPLICATIONS n n n n n The LT(R)3061 is a micropower, low dropout (LDO) linear regulator that operates over a 1.6V to 45V supply range and is available in a series of fixed output and adjustable versions. The device supplies 100mA of output current with a typical dropout voltage of 250mV. A single external capacitor provides programmable low noise reference performance and output soft-start functionality. The LT3061's quiescent current is merely 45A and provides fast transient response with a minimum 3.3F output capacitor. In shutdown, quiescent current is less than 3A and the reference soft start capacitor is reset. The LT3061 features an NMOS pull-down that discharges the output when SHDN or IN is driven low. Internal protection circuitry includes reverse-battery protection, reverse-current protection, current limit with foldback and thermal shutdown. The LT3061 is available in fixed output voltages of 3.3V and 5V, and as an adjustable device with an output voltage range from the 600mV reference up to 19V. The LT3061 is offered in the thermally enhanced 8-lead 2mm x 3mm DFN and MSOP packages. 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TYPICAL APPLICATION LT3061-3.3 Active Output Discharge 3.3V Low Noise Regulator VIN 5V 1F VOUT 3.3V 100mA OUT LT3061-3.3 SHDN GND 10nF ADJ BYP 10nF 3061 TA01 3.3V 10F 0.5V/DIV IN 1V SHDN 0V 1ms/DIV 3061 TA01a COUT = 10F IL = 0 3061fb For more information www.linear.com/LT3061 1 LT3061 Series ABSOLUTE MAXIMUM RATINGS (Note 1) IN Pin Voltage..........................................................50V OUT Pin Voltage............................................... +20V, -1V Input to Output Differential Voltage (Note 2)............50V ADJ Pin Voltage.......................................................50V SHDN Pin Voltage....................................................50V REF/BYP Pin Voltage..................................... -0.3V to 1V Output Short-Circuit Duration........................... Indefinite Operating Junction Temperature (Notes 3, 5, 12) E-, I-Grades........................................ -40C to 125C MP-Grade........................................... -55C to 150C H-Grade.............................................. -40C to 150C Storage Temperature Range................... -65C to 150C Lead Temperature (Soldering, 10 sec) MS8E Package Only........................................... 300C PIN CONFIGURATION TOP VIEW ADJ 2 OUT 3 TOP VIEW 8 GND REF/BYP 1 9 GND REF/BYP ADJ OUT OUT 7 SHDN 6 IN 5 IN OUT 4 9 GND 8 7 6 5 GND SHDN IN IN MS8E PACKAGE 8-LEAD PLASTIC MSOP DCB PACKAGE 8-LEAD (2mm x 3mm) PLASTIC DFN TJMAX = 150C, JA = 29C/W TO 45C/W, JC = 5C/W TO 10C/W EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB TJMAX = 150C, JA = 38C/W TO 45C/W, JC = 3.5C/W EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION 1 2 3 4 http://www.linear.com/product/LT3061#orderinfo LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3061EDCB#PBF LT3061EDCB#TRPBF LGNF 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061IDCB#PBF LT3061IDCB#TRPBF LGNF 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061HDCB#PBF LT3061HDCB#TRPBF LGNF 8-Lead (2mm x 3mm) Plastic DFN -40C to 150C LT3061MPDCB#PBF LT3061MPDCB#TRPBF LGNF 8-Lead (2mm x 3mm) Plastic DFN -55C to 150C LT3061EMS8E#PBF LT3061EMS8E#TRPBF LTGNG 8-Lead Plastic MSOP -40C to 125C LT3061IMS8E#PBF LT3061IMS8E#TRPBF LTGNG 8-Lead Plastic MSOP -40C to 125C LT3061HMS8E-5#PBF LT3061HMS8E#TRPBF LTGNG 8-Lead Plastic MSOP -40C to 150C LT3061MPMS8E#PBF LT3061MPMS8E#TRPBF LTGNG 8-Lead Plastic MSOP -55C to 150C 2 3061fb For more information www.linear.com/LT3061 LT3061 Series ORDER INFORMATION http://www.linear.com/product/LT3061#orderinfo LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3061EDCB-3.3#PBF LT3061EDCB-3.3#TRPBF LGZB 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061IDCB-3.3#PBF LT3061IDCB-3.3#TRPBF LGZB 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061EDCB-5#PBF LT3061EDCB-5#TRPBF LGYZ 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061IDCB-5#PBF LT3061IDCB-5#TRPBF LGYZ 8-Lead (2mm x 3mm) Plastic DFN -40C to 125C LT3061EMS8E-3.3#PBF LT3061EMS8E-3.3#TRPBF LTGZJ 8-Lead Plastic MSOP -40C to 125C LT3061IMS8E-3.3#PBF LT3061IMS8E-3.3#TRPBF LTGZJ 8-Lead Plastic MSOP -40C to 125C LT3061EMS8E-5#PBF LT3061EMS8E-5#TRPBF LTGZH 8-Lead Plastic MSOP -40C to 125C LT3061IMS8E-5#PBF LT3061IMS8E-5#TRPBF LTGZH 8-Lead Plastic MSOP -40C to 125C Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult ADI Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 3) PARAMETER CONDITIONS Minimum Input Voltage (Note 4) ILOAD = 100mA Regulated Output Voltage (Note 5) LT3061-3.3: VIN = 3.9, ILOAD = 1mA LT3061-3.3: 3.9V < VIN < 45V, 1mA < ILOAD < 100mA LT3061-5: VIN = 5.6, ILOAD = 1mA LT3061-5: 5.6V < VIN < 45V, 1mA < ILOAD < 100mA ADJ Pin Voltage (Notes 4, 5) Line Regulation (Note 4) ILOAD = 1mA Load Regulation (Note 4) ILOAD = 1mA to 100mA Dropout Voltage VIN = VOUT(NOMINAL) (Notes 6, 7) GND Pin Current VIN = VOUT(NOMINAL) + 0.6V (Notes 6, 8) MIN TYP MAX 1.6 2.1 V 3.3 l 3.267 3.234 4.950 4.900 3.333 3.366 5.050 5.100 V V V V VIN = 2.1V, ILOAD = 1mA 2.1V < VIN < 45V, 1mA < ILOAD < 100mA (E-, I-Grades) 2.1V < VIN < 45V, 1mA < ILOAD < 100mA (MP-, H-Grades) l l 594 588 585 600 600 600 606 612 612 mV mV mV LT3061-3.3: VIN = 3.9V to 45V (E-, I-Grades) LT3061-5: VIN = 5.6V to 45V (E-, I-Grades) l l 1.6 3.1 22 33 mV mV LT3061: VIN = 2.1V to 45V (E-, I-Grades) LT3061: VIN = 2.1V to 45V (MP-, H-Grades) l l 0.5 4 6 mV mV LT3061-3.3: VIN = 3.9V (E-, I-Grades) LT3061-5: VIN = 5.6V (E-, I-Grades) l l 4.4 5.0 25 36 mV mV LT3061: VIN = 2.1V (E-, I-Grades) LT3061: VIN = 2.1V (MP-, H-Grades) l l 0.2 4 9 mV mV ILOAD = 1mA ILOAD = 1mA 65 l 110 180 mV mV ILOAD = 10mA ILOAD = 10mA 130 l 180 270 mV mV ILOAD = 50mA ILOAD = 50mA 195 l 240 350 mV mV ILOAD = 100mA ILOAD = 100mA 250 l 290 430 mV mV ILOAD = 0 ILOAD = 1mA ILOAD = 10mA ILOAD = 50mA ILOAD = 100mA l l l l l 45 70 225 0.8 2 90 120 500 1.8 4 A A A mA mA l l 5 UNITS 3061fb For more information www.linear.com/LT3061 3 LT3061 Series ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 3) PARAMETER CONDITIONS Output Voltage Noise COUT = 10F, ILOAD = 100mA, CREF/BYP = 0.01F VOUT = 600mV, BW = 10Hz to 100kHz MIN ADJ Pin Bias Current (Notes 4, 9) Shutdown Threshold VOUT = Off to On VOUT = On to Off l l SHDN Pin Current (Note 10) VSHDN = 0V VSHDN = 45V l l Quiescent Current in Shutdown VIN = 45V, VSHDN = 0V Ripple Rejection VIN - VOUT = 1.5V (AVG), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 200mA LT3061-3.3 LT3061-5 LT3061 (Note 4) Current Limit VIN = 7V, VOUT = 0 VIN = VOUT(NOMINAL) + 1V (Note 11), VOUT = -5% l Input Reverse Leakage Current VIN = -45V, VOUT = 0 l Output Discharge Time (Note 6) VOUT Discharged to 10% of Nominal, COUT = 10F l Reverse Output Current LT3061-3.3: VOUT = 3.3V, VIN = VSHDN = 2.1V LT3061-5: VOUT = 5V, VIN = VSHDN = 2.1V LT3061: VOUT = 3.3V, VIN = VSHDN = 2.1V (Note 4) 4 MAX 30 l Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Absolute maximum input to output differential voltage is not achievable with all combinations of rated IN pin and OUT pin voltages. With the IN pin at 50V, the OUT pin may not be pulled below 0V. The total measured voltage from IN to OUT must not exceed 50V. Note 3: The LT3061 is tested and specified under pulse load conditions such that TJ TA. The LT3061E regulators are 100% tested at TA = 25C and performance is guaranteed from 0C to 125C. Performance at -40C to 125C is assured by design, characterization and correlation with statistical process controls. The LT3061I regulators are guaranteed over the full -40C to 125C operating junction temperature range. The LT3061MP regulators are 100% tested over the -55C to 150C operating junction temperature. The LT3061H regulators are 100% tested at the 150C operating junction temperature. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperature greater than 125C. Note 4: The LT3061 adjustable version is tested and specified for these conditions with the ADJ connected to the OUT pin. Note 5: Maximum junction temperature limits operating conditions. The regulated output voltage specification does not apply for all possible combinations of input voltage and output current. Limit the output current range if operating at the maximum input voltage. Limit the input-to-output voltage differential if operating at maximum output current. Current limit foldback limits the maximum output current as a function of input-tooutput voltage. See Current Limit vs VIN - VOUT in the Typical Performance Characteristics section. TYP 0.3 58 55 70 110 UNITS VRMS 15 60 nA 0.8 0.7 1.5 V V 1.2 <1 3 A A 1.25 3 A 73 70 85 dB dB dB 180 mA mA 1 mA 0.75 2 ms 7.3 8.4 2.5 15 15 15 A A A Note 6: To satisfy minimum input voltage requirements, the LT3061 adjustable version is tested and specified for these conditions with an external resistor divider (bottom 60k, top 230k) for an output voltage of 2.9V. The external resistor divider adds 10A of DC load on the output. The external current is not factored into GND pin current. Note 7: Dropout voltage is the minimum input-to-output voltage differential needed to maintain regulation at a specified output current. In dropout, the output voltage equals: (VIN - VDROPOUT). Note 8: GND pin current is tested with VIN = VOUT(NOMINAL) + 0.6V and a current source load. GND pin current will increase in dropout. See GND pin current curves in the Typical Performance Characteristics section. For fixed voltage options, an internal resistor divider will add 5A to the GND pin current. See the GND Pin Current curves in the Typical Performance Characteristics section. Note 9: ADJ pin bias current flows out of the ADJ pin. Note 10: SHDN pin current flows into the SHDN pin. Note 11: To satisfy requirements for minimum input voltage, current limit is tested at VIN = VOUT(NOMINAL) + 1V or VIN = 2.1V, whichever is greater. Note 12: This IC includes thermal limit which protects the device during momentary overload conditions. Junction temperature exceeds 125C (E- and I-Grades) or 150C (MP- and H-Grades) if thermal limit is active. Continuous operation above the specified maximum junction temperature may impair device reliability. 3061fb For more information www.linear.com/LT3061 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS Guaranteed Dropout Voltage 450 450 400 400 TJ = 150C 300 TJ = 125C 250 200 TJ = 25C 150 100 400 TJ = 150C 300 TJ = 25C 250 200 150 100 50 50 0 = TEST POINTS DROPOUT VOLTAGE (mV) 350 0 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 0 LT3061-3.3 Output Voltage 200 150 IL = 1mA 3061 G03 ADJ Pin Voltage IL = 1mA 608 3.278 3.267 ADJ PIN VOLTAGE (mV) OUTPUT VOLTAGE (V) 3.289 5.040 5.020 5.000 4.980 4.960 4.940 3.256 IL = 1mA 610 5.060 3.300 IL = 1mA 612 5.080 3.311 IL = 10mA 100 LT3061-5 Output Voltage 3.344 OUTPUT VOLTAGE (V) 250 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 5.100 3.322 IL = 50mA 300 3061 G02 3.366 3.333 IL = 100mA 350 50 3061 G01 3.355 Dropout Voltage 450 350 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) Typical Dropout Voltage TA = 25C, unless otherwise noted. 606 604 602 600 598 596 594 592 3.245 4.920 590 3.234 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 4.900 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 588 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) LT3061 G03a LT3061 G03b 3061 G04 LT3061-3.3 Quiescent Current LT3061-5 Quiescent Current 250 70 225 225 200 200 60 50 VIN = VSHDN = 6V VOUT = 5V IL = 5A 40 30 20 10 VIN = 6V ALL OTHER PINS = 0V 175 150 125 100 75 VSHDN = VIN 50 25 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) QUIESCENT CURRENT (A) 250 QUIESCENT CURRENT (A) QUIESCENT CURRENT (A) Quiescent Current 80 0 VSHDN = 0V 0 1 2 3 4 5 6 7 VIN (V) 8 9 10 11 12 3061 G05a 175 150 125 100 VSHDN = VIN 75 50 25 0 VSHDN = 0V 0 1 2 3 4 5 6 7 VIN (V) 8 9 10 11 12 3061 G05b 3061 G05 3061fb For more information www.linear.com/LT3061 5 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS LT3061-3.3 GND Pin Current Quiescent Current QUIESCENT CURRENT (A) TJ = 25C 110 V OUT = 5V 100 IL = 10A GND PIN CURRENT (mA) 80 70 60 50 40 30 2.25 2.25 RL = 33, IL = 100mA 1.75 1.50 1.25 RL = 66, IL = 50mA 1.00 0.75 RL = 3.3k, IL = 1mA 0.50 20 0 2.50 2.00 90 0 5 10 15 20 25 VIN (V) 30 35 40 0 45 2.00 0 1 2 3 4 5 6 7 VIN (V) 8 RL = 50, IL = 100mA 1.75 1.50 1.25 1.00 RL = 100, IL = 50mA 0.75 RL = 5k, IL = 1mA 0.50 RL = 330, IL = 10mA 0.25 VSHDN = 0V, RL = 0 LT3061-5 GND Pin Current 2.50 GND PIN CURRENT (mA) 120 10 TA = 25C, unless otherwise noted. RL = 500, IL = 10mA 0.25 0 9 10 11 12 3061 G6a 0 1 2 3 4 5 6 7 VIN (V) 8 9 10 11 12 3061 G06b 3061 G06 GND Pin Current VOUT = 0.6V 2.00 1.75 1.50 1.25 1.00 0.75 VIN = VOUT(NOMINAL) +1V 3.5 0.50 3.0 2.5 2 1.5 1.0 0.5 0.25 0 1 2 3 4 5 6 VIN (V) 7 8 9 0 10 0 10 20 30 40 50 60 70 80 90 100 ILOAD (mA) 3061 G07 SHDN Pin Input Current 3061 G09 SHDN Pin Input Current 3.0 3.0 2.5 2.5 SHDN PIN INPUT CURRENT (A) SHDN PIN INPUT CURRENT (A) 1.5 1.4 1.3 1.2 1.1 1.0 0.9 OFF TO ON 0.8 0.7 0.6 ON TO OFF 0.5 0.4 0.3 0.2 0.1 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G08 2.0 1.5 1.0 0.5 ADJ Pin Bias Current 50 SHDN = 45V 40 ADJ PIN BIAS CURRENT (nA) 0.00 SHDN Pin Threshold SHDN PIN THRESHOLD (V) RL = 6, IL = 100mA RL = 12, IL = 50mA RL = 60, IL = 10mA RL = 600, IL = 1mA 2.25 GND PIN CURRENT (mA) GND Pin Current vs ILOAD 4.0 GND PIN CURRENT (mA) 2.50 2.0 1.5 1.0 0.5 30 20 10 0 -10 -20 -30 -40 0 0 5 10 15 20 25 30 35 SHDN PIN VOLTAGE (V) 40 45 3061 G10 6 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G11 -50 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G12 3061fb For more information www.linear.com/LT3061 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS Internal Current Limit 200 175 150 125 100 75 VIN = 7V 225 VOUT = 0V 200 175 150 125 100 75 50 50 25 25 0 0 Output Discharge Time COUT = 10F, VIN = VOUT +1V OUTPUT DISCHARGE TIME (ms) 2.5 2.0 1.5 OUTPUT DISCHARGE FOLDBACK STARTS 1.0 0.5 0 2 4 6 8 10 12 14 16 18 20 OUTPUT VOLTAGE (V) 3061 G15 Output Discharge vs VOUT CREF/BYP = 0 OUT = 20V OUT = 12V OUT = 5V OUT = 3.3V OUT = 1.2V 5 3.0 3061 G14 3061 G13 6 COUT = 10F 3.5 VIN = VOUT +1V 0 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 5 10 15 20 25 30 35 40 45 INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V) 7 Output Discharge Time 4.0 OUTPUT DISCHARGE TIME (ms) TJ = 150C TJ = 125C TJ = 25C TJ = -40C TJ = -55C 225 CURRENT LIMIT (mA) Internal Current Limit 250 CURRENT LIMIT (mA) 250 TA = 25C, unless otherwise noted. Output Discharge vs VOUT CREF/BYP = 0 12V 12V 10V 4 3 5V/DIV 15V 12V 6V 5V 3.3V 2V 1.2V 2 0V SHDN: 0 TO 1V 1 1ms/DIV 0V SHDN: 0 TO 1V 3061 G17 1ms/DIV VIN = VOUT +1V COUT = 10F IFB-DIVIDER = 5A 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 20V 20V 8V 2V/DIV 3061 G18 VIN = VOUT +1V COUT = 10F IFB-DIVIDER = 5A 3061 G16 Reverse Output Current VIN = VSHDN = 2.1V 45 VADJ = VOUT OUTPUT CURRENT (A) OUTPUT CURRENT (A) 40 35 30 25 20 15 10 5 0 0 2 4 6 8 10 12 14 16 18 20 VOUT (V) 3061 G19 Input Ripple Rejection 150 140 VOUT = VADJ = 3.3V V = VSHDN = 2.1V 130 IN 120 110 100 IADJ 90 80 70 60 50 40 30 20 IOUT 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G20 90 VOUT = 0.6V 80 RIPPLE REJECTION (dB) Reverse Output Current 50 70 60 VOUT = 5V COUT = 10F 50 40 30 20 ILOAD = 100mA COUT = 3.3F 10 CREF/BYP = CFF = 0 VIN = VOUT +1.5V +50mVRMS RIPPLE 0 10 1k 100 10k 100k 1M 10M FREQUENCY (Hz) 3061 G21 3061fb For more information www.linear.com/LT3061 7 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS 70 60 50 40 30 20 10 0 10 100 10k 100k 1k FREQUENCY (Hz) 1M CREF/BYP = 10nF 90 80 CREF/BYP = 0 70 60 50 40 30 20 I LOAD = 100mA 10 VOUT = 0.6V VIN = 2.6V +0.5VP-P RIPPLE, f = 120Hz 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) CREF/BYP = CFF = 0 CREF/BYP = 10nF, CFF = 0 CREF/BYP = 10nF, CFF = 10nF 10M 2.2 3061 G22 2.0 MINIMUM INPUT VOLTAGE (V) RIPPLE REJECTION (dB) 80 100 RIPPLE REJECTION (dB) VIN = 6.5V +50mVRMS RIPPLE ILOAD = 100mA COUT = 10F VOUT = 5V 90 Minimum Input Voltage Input Ripple Rejection Input Ripple Rejection 100 TA = 25C, unless otherwise noted. 1.8 ILOAD = 100mA 1.6 1.4 ILOAD = 50mA 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G23 3061 G24 5V Transient Response CFF = 0, IOUT = 10mA to 100mA Load Regulation 5V Transient Response CFF = 10nF, IOUT = 10mA to 100mA 5.0 0 VOUT 50mV/DIV LOAD REGULATION (mV) -5.0 VOUT 20mV/DIV -10.0 -15.0 -20.0 -25.0 IOUT 50mA/DIV -30.0 IL = 1mA to 100mA -35.0 -40.0 LT3061, VOUT = 0.6V LT3061-3.3 LT3061-5 -45.0 IOUT 50mA/DIV 3061 G26 100s/DIV -50.0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (C) 3061 G27 20s/DIV VIN = 6V COUT = 10F IFB-DIVIDER = 5A VIN = 6V COUT = 10F IFB-DIVIDER = 5A Output Noise Spectral Density vs CREF/BYP, CFF = 0 Output Noise Spectral Density vs CFF, CREF/BYP = 10nF 10 1 0.1 0.01 10 5V 3.3V 2.5V 1.2V 0.6V 100 COUT = 10F IL = 100mA 1k 10k FREQUENCY (Hz) 100k 3061 G28 8 OUTPUT NOISE SPECTRAL DENSITY (V/Hz) OUTPUT NOISE SPECTRAL DENSITY (V/Hz) Output Noise Spectral Density CREF/BYP = 0, CFF = 0 10 CREF/BYP = 100pF VOUT = 5V 1 VOUT = 0.6V 0.1 CREF/BYP = 10nF COUT = 10F IL = 100mA 0.01 10 100 CREF/BYP = 1nF 1k 10k FREQUENCY (Hz) 100k 3061 G29 OUTPUT NOISE SPECTRAL DENSITY (V/Hz) 3061 G25 10 CFF = 100pF 1 CFF = 0 CFF = 10nF 0.1 VOUT = 5V COUT = 10F IL = 100mA 0.01 10 100 CFF = 1nF 1k 10k FREQUENCY (Hz) 100k 3061 G30 3061fb For more information www.linear.com/LT3061 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS RMS Output Noise vs Load Current CREF/BYP = 10nF, CFF = 0 CREF/BYP = 0 90 OUTPUT NOISE VOLTAGE (VRMS) OUTPUT NOISE VOLTAGE (VRMS) f = 10Hz TO 100kHz 100 COUT = 10F CREF/BYP = 10pF 80 70 60 CREF/BYP = 100pF 50 40 CREF/BYP = 10nF 30 20 CREF/BYP = 100nF 10 0 0.01 0.1 10 1 LOAD CURRENT (mA) 100 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 0.01 VOUT = 5V VOUT = 3.3V VOUT = 2.5V VOUT = 1.2V VOUT = 0.6V RMS Output Noise vs Feedforward Capacitor (CFF) f = 10Hz TO 100kHz COUT = 10F 1 0.1 10 LOAD CURRENT (mA) OUTPUT NOISE VOLTAGE (VRMS) RMS Output Noise vs CREF/BYP VOUT = 0.6V 110 TA = 25C, unless otherwise noted. 100 130 f = 10Hz TO 100kHz 120 CREF/BYP = 10nF VOUT = 5V COUT = 10F 110 IFB-DIVIDER = 5A 100 ILOAD = 100mA 90 80 VOUT = 3.3V 70 VOUT = 2.5V 60 50 40 30 VOUT = 0.6V 20 V OUT = 1.2V 10 0 0.1 10 0.01 1 FEEDFORWARD CAPACITOR, CFF (nF) 3061 G32 3061 G31 3061 G33 Transient Response, VOUT = 5V Load Dump, VIN = 12V to 45V 5V 10Hz to 100kHz Output Noise CREF/BYP = 10nF, CFF = 10nF 5V 10Hz to 100kHz Output Noise CREF/BYP = 10nF, CFF = 0 VOUT 5mV/DIV 45V VOUT 100V/DIV VOUT 100V/DIV VIN 10V/DIV 12V 1ms/DIV 3061 G34 3061 G35 1ms/DIV SHDN Transient Response CREF/BYP = 0 SHDN Transient Response CREF/BYP = 10nF VOUT 2V/DIV RL = 500k VOUT 2V/DIV RL = 500k REF/BYP 500mV/DIV REF/BYP 500mV/DIV SHDN 1V/DIV SHDN 1V/DIV 2ms/DIV COUT = 10F CFF = 0 3061 G36 COUT = 10F CREF/BYP = CFF = 10nF IFB-DIVIDER = 5A COUT = 10F ILOAD = 100mA COUT = 10F ILOAD = 100mA 1ms/DIV 3061 G37 2ms/DIV 3061 G38 COUT = 10F CFF = 0 3061fb For more information www.linear.com/LT3061 9 LT3061 Series TYPICAL PERFORMANCE CHARACTERISTICS Start-Up Time vs REF/BYP Capacitor 1000 CFF = 0 1 0.1 0.01 0.01 Start-up Time vs CFF 100 10 START-UP TIME (ms) START-UP TIME (ms) 100 TA = 25C, unless otherwise noted. VOUT = 1.2V IFB-DIVIDER = 5A LT3061-3.3 LT3061-5 10 1 0.1 0.1 10 1 REF/BYP CAPACITOR (nF) 100 0.01 0.01 0.1 1 10 FEED-FORWARD CAPACITOR, CFF (nF) 100 LT3061 G40 3061 G39 10 3061fb For more information www.linear.com/LT3061 LT3061 Series PIN FUNCTIONS REF/BYP (Pin 1): Reference/ Bypass. Connecting a single capacitor from this pin to GND bypasses the LT3061's reference noise and soft-starts the reference. A 10nF bypass capacitor typically reduces output voltage noise to 30VRMS in a 10Hz to 100kHz bandwidth. Soft-start time is directly proportional to the REF/BYP capacitor value. If the LT3061 is placed in shutdown, REF/BYP is actively pulled low by an internal device to reset soft-start. If low noise or soft-start performance is not required, this pin must be left floating (unconnected). Do not drive this pin with any active circuitry. ADJ (Pin 2): Adjust. This pin is the error amplifier's inverting terminal. Its typical bias current of 15nA flows out of the pin (see curve of ADJ Pin Bias Current vs Temperature in the Typical performance Characteristics section). The ADJ pin voltage is 600mV referenced to GND. OUT (Pins 3, 4): Output. These pins supply power to the load. A minimum output capacitor of 3.3F is required to prevent oscillations. Large load transient applications require larger output capacitors to limit peak voltage transients. See the Applications Information section for more information on reverse output characteristics. The output voltage range is 600mV to 19V. If the LT3061 is placed in shutdown, OUT is actively discharged by an internal NMOS device. Gate drive is controlled to insure that a 10F capacitor is discharged 90% in 2ms or less. If IN is driven low, OUT is actively discharged to ~800mV. For OUT voltages greater than 6V, current limit foldback is implemented to protect the NMOS device and discharge rates increase. See the Applications Information section for more information. IN (Pins 5, 6): Input. These pins supply power to the device. The LT3061 requires a bypass capacitor at IN if the device is located more than six inches from the main input filter capacitor. In general, the output impedance of a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1F to 10F suffices. See Input Capacitance and Stability in the Application Information section for more information. The LT3061 withstands reverse voltages on the IN pin with respect to the GND and OUT pins. In a reversed input situation, such as the battery plugged in backwards, the LT3061 behaves as if a large value resistor is in series with its input. Limited reverse current flows into the LT3061 and no reverse voltage appears at the load. The device protects itself and the load. SHDN (Pin 7): Shutdown. Pulling the SHDN pin low puts the LT3061 into a low power state and turns the output off. Drive the SHDN pin with either logic or an open collector/drain with a pull-up resistor. The resistor supplies the pull-up current to the open collector/drain logic, normally several microamperes, and the SHDN pin current, typically less than 3A. If unused, connect the SHDN pin to VIN. The LT3061 does not function if the SHDN pin is not connected. The SHDN pin cannot be driven below GND unless tied to the IN pin. If the SHDN pin is driven below GND while IN is powered, the output will turn on. SHDN pin logic cannot be referenced to a negative rail. GND (Pin 8, Exposed Pad Pin 9): Ground. Connect the bottom of the external resistor divider that sets the output voltage directly to GND for optimum regulation. Tie the exposed pad Pin 9 directly to Pin 8 and the PCB ground. This exposed pad provides enhanced thermal performance with its connection to the PCB ground. See the Applications Information section for thermal considerations and calculating junction temperature. 3061fb For more information www.linear.com/LT3061 11 LT3061 Series APPLICATIONS INFORMATION The LT3061 is a 100mA low dropout regulator with shutdown that is available in fixed output and adjustable versions. The device is capable of supplying 100mA at a typical dropout voltage of 250mV and operates over a 1.6V to 45V input range. A single external capacitor provides programmable low noise reference performance and output soft-start functionality. For example, connecting a 10nF capacitor from the REF/BYP pin to GND lowers output noise to 30VRMS over a 10Hz to 100kHz bandwidth. This capacitor also soft-starts the reference and prevents output voltage overshoot at turn-on. The LT3061's quiescent current is merely 45A, while providing fast transient response with a 3.3F minimum low ESR ceramic output capacitor. In shutdown, quiescent current is less than 3A and the reference soft-start capacitor and output are reset. The LT3061 optimizes stability and transient response with low ESR, ceramic output capacitors. The LT3061 does not require the addition of ESR as is common with other regulators. The LT3061 has an adjustable output and typically provides 0.1% line regulation and 0.1% load regulation. A curve of load regulation appears in the Typical Performance Characteristics section. The LT3061 discharges the output in shutdown. Internal protection circuitry includes reverse-battery protection, reverse-current protection, current limit with foldback and thermal shutdown. Adjustable Operation The adjustable LT3061 has an output voltage range of 0.6V to 19V. Output voltage is set by the ratio of two external resistors, as shown in Figure 1. The device regulates the output to maintain the ADJ pin voltage at 0.6V referenced to ground. The current in R1 equals 0.6V/R1, and R2's current is R1's current minus the ADJ pin bias current. The ADJ pin bias current, 15nA at 25C, flows from the ADJ pin through R1 to GND. Calculate the output voltage using the formula in Figure 1. R1's value should not be greater than 124k to provide a minimum ~5A load current so that output voltage errors, caused by the ADJ pin 12 bias current, are minimized. Note that in shutdown, the output is turned off and the divider current is zero. Curves of ADJ Pin Voltage vs Temperature and ADJ Pin Bias Current vs Temperature appear in the Typical Performance Characteristics section. IN VIN OUT LT3061 SHDN VOUT R2 ! R2 $ VOUT = 0.6V # 1+ & - (IADJ *R2) " R1 % ADJ GND REF/BYP VADJ = 0.6V R1 IADJ = 15nA at 25C OUTPUT RANGE = 0.6V to 19V 3061 F01 Figure 1. Adjustable Operation The LT3061 is tested and specified with the ADJ pin tied to the OUT pin for an output voltage of 0.6V. Specifications for output voltages greater than 0.6V are proportional to the ratio of the desired output voltage to 0.6V: VOUT/0.6V. For example, load regulation for an output current change of 1mA to 100mA is -0.2mV typical at VOUT = 0.6V. At VOUT = 12V, load regulation is: 12V * ( -0.2mV ) = -4mV 0.6V Table 1 shows 1% resistor divider values for some common output voltages with a resistor divider current of 5A. Table 1. Output Voltage Resistor Divider Values VOUT (V) R1 (k ) R2 (k ) 1.2 118 118 1.5 121 182 1.8 124 249 2.5 115 365 3 124 499 3.3 124 562 5 115 845 12 124 2370 15 124 3010 3061fb For more information www.linear.com/LT3061 LT3061 Series APPLICATIONS INFORMATION The LT3061 regulator provides low output voltage noise over the 10Hz to 100kHz bandwidth while operating at full load with the addition of a bypass capacitor (CREF/BYP) from the REF/BYP pin to GND. A good quality low leakage capacitor is recommended. This capacitor bypasses the reference of the regulator, providing a low frequency noise pole for the internal reference. With the use of 10nF for CREF/BYP, the output voltage noise decreases to as low as 30VRMS when the output voltage is set for 0.6V. For higher output voltages (generated by using a resistor divider), the output voltage noise gains up accordingly when using CREF/BYP by itself. To lower the output voltage noise for higher output voltages, include a feedforward capacitor (CFF) from VOUT to the ADJ pin. A good quality, low leakage capacitor is recommended. This capacitor bypasses the error amplifier of the regulator, providing a low frequency noise pole. With the use of 10nF for both CFF and CREF/BYP, output voltage noise decreases to 30VRMS when the output voltage is set to 5V by a 5A feedback resistor divider. If the current in the feedback resistor divider is doubled, CFF must also be doubled to achieve equivalent noise performance. Feedforward capacitance can also be used in fixed-voltage parts; the feedforward capacitor is connected from OUT to ADJ in the same manner. In this case, the current in the internal feedback resistor divider is 5A. IN VIN OUT LT3061 SHDN VOUT R2 CFF COUT ADJ GND REF/BYP R1 4.7nF * (I FB-DIVIDER ) 5A V I FB-DIVIDER = OUT R1+ R2 CFF CREF/BYP 3061 F02 Figure 2. Feedforward Capacitor for Fast Transient Response VOUT = 5V COUT = 10F IFB-DIVIDER = 5A 0 VOUT 50mV/DIV Higher values of output voltage noise may be measured if care is not exercised with regard to circuit layout and testing. Crosstalk from nearby traces can induce unwanted noise onto the LT3061's output. Power supply ripple rejection must also be considered. The LT3061 regulator does not have unlimited power supply rejection and will pass a small portion of the input noise through to the output. capacitor, the settling time will increase as the output voltage is raised above 0.6V. Use the equation in Figure 2 to determine the minimum value of CFF to achieve a transient response that is similar to 0.6V output voltage performance regardless of the chosen output voltage (see Figure 3 and Transient Response in the Typical Performance Characteristics section). FEEDFORWARD CAPACITOR, CFF Bypass Capacitance, Output Voltage Noise and Transient Response 100pF 1nF 10nF LOAD CURRENT 100mA/DIV 100s/DIV 3061 F03 Figure 3. Transient Response vs Feedforward Capacitor Using a feedforward capacitor (CFF) from VOUT to the ADJ pin has the added benefit of improving transient response for output voltages greater than 0.6V. With no feedforward 3061fb For more information www.linear.com/LT3061 13 LT3061 Series APPLICATIONS INFORMATION During start-up, the internal reference soft-starts if a reference bypass capacitor is present. Regulator startup time is directly proportional to the size of the bypass capacitor, slowing to 6ms with a 10nF bypass capacitor (See SHDN Transient Response vs REF/BYP Capacitor in the Typical Performance Characteristics section). The reference bypass capacitor is actively pulled low during shutdown to reset the internal reference. Start-up time is also affected by the use of a feedforward capacitor. Start-up time is directly proportional to the size of the feedforward capacitor and output voltage, and is inversely proportional to the feedback resistor divider current, slowing to 15ms with a 4.7nF feedforward capacitor and a 10F output capacitor for an output voltage set to 5V by a 5A feedback resistor divider. dielectrics yield much more stable characteristics and are more suitable for use as the output capacitor. The X7R type works over a wider temperature range and has better temperature stability, while the X5R is less expensive and is available in higher values. Care still must be exercised when using X5R and X7R capacitors; the X5R and X7R codes only specify operating temperature range and maximum capacitance change over temperature. Capacitance change due to DC bias with X5R and X7R capacitors is better than Y5V and Z5U capacitors, but can still be significant enough to drop capacitor values below appropriate levels. Capacitor DC bias characteristics tend to improve as component case size increases, but expected capacitance at operating voltage should be verified. 20 Output Capacitance X5R -20 -40 -60 Y5V -80 -100 0 2 4 14 8 6 10 12 DC BIAS VOLTAGE (V) 16 3061 F04 Figure 4. Ceramic Capacitor DC Bias Characteristics 40 20 CHANGE IN VALUE (%) Give extra consideration to the use of ceramic capacitors. Manufacturers make ceramic capacitors with a variety of dielectrics, each with different behavior across temperature and applied voltage. The most common dielectrics are specified with EIA temperature characteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and Y5V dielectrics provide high C-V products in a small package at low cost, but exhibit strong voltage and temperature coefficients as shown in Figures 4 and 5. When used with a 5V regulator, a 16V 10F Y5V capacitor can exhibit an effective value as low as 1F to 2F for the DC bias voltage applied and over the operating temperature range. The X5R and X7R CHANGE IN VALUE (%) 0 The LT3061 regulator is stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. Use a minimum output capacitor of 3.3F with an ESR of 3 or less to prevent oscillations. The LT3061 is a micropower device and output load transient response is a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide improved transient response for larger load current changes. Bypass capacitors, used to decouple individual components powered by the LT3061, will increase the effective output capacitor value. For applications with large load current transients, a low ESR ceramic capacitor in parallel with a bulk tantalum capacitor often provides an optimally damped response. 14 BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10F X5R 0 -20 -40 Y5V -60 -80 BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10F -100 -50 -25 50 25 75 0 TEMPERATURE (C) 100 125 3061 F05 Figure 5. Ceramic Capacitor Temperature Characteristics 3061fb For more information www.linear.com/LT3061 LT3061 Series APPLICATIONS INFORMATION Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor, the stress can be induced by vibrations in the system or thermal transients. The resulting voltages produced can cause appreciable amounts of noise. A ceramic capacitor produced the trace in Figure 6 in response to light tapping from a pencil. Similar vibration induced behavior can masquerade as increased output voltage noise. VOUT = 0.6V COUT = 10F CREF/BYP = 10nF ILOAD = 100mA VOUT 500V/DIV 4ms/DIV 3061 F06 Figure 6. Noise Resulting from Tapping on a Ceramic Capacitor Input Capacitance and Stability Low ESR, ceramic input bypass capacitors are acceptable for applications without long input leads. However, applications connecting a power supply to an LT3061 circuit's IN and GND pins with long input wires combined with a low ESR, ceramic input capacitor are prone to voltage spikes, reliability concerns and application-specific board oscillations. The input wire inductance found in many battery-powered applications, combined with the low ESR ceramic input capacitor, forms a high Q LC resonant tank circuit. In some instances this resonant frequency beats against the output current dependent LDO bandwidth and interferes with proper operation. Simple circuit modifications/solutions are then required. This behavior is not indicative of LT3061 instability, but is a common ceramic input bypass capacitor application issue. The self-inductance, or isolated inductance, of a wire is directly proportional to its length. Wire diameter is not a major factor on its self-inductance. For example, the selfinductance of a 2-AWG isolated wire (diameter = 0.26") is about half the self-inductance of a 30-AWG wire (diameter = 0.01"). One foot of 30-AWG wire has approximately 465nH of self-inductance. Two methods can reduce wire self-inductance. One method divides the current flowing towards the LT3061 between two parallel conductors. In this case, the farther apart the wires are from each other, the more the self-inductance is reduced; up to a 50% reduction when placed a few inches apart. Splitting the wires connects two equal inductors in parallel, but placing them in close proximity creates mutual inductance adding to the self-inductance. The second and most effective way to reduce overall inductance is to place both forward and return current conductors (the input and GND wires) in very close proximity. Two 30-AWG wires separated by only 0.02", used as forward and return current conductors, reduce the overall self-inductance to approximately one-fifth that of a single isolated wire. If a battery, mounted in close proximity, powers the LT3061, a 1F input capacitor suffices for stability. However, if a distant supply powers the LT3061, use a larger value input capacitor. Use a rough guideline of 1F (in addition to the 1F minimum) per 8 inches of wire length. The minimum input capacitance needed to stabilize the application also varies with power supply output impedance variations. Placing additional capacitance on the LT3061's output also helps. However, this requires an order of magnitude more capacitance in comparison with additional LT3061 input bypassing. Series resistance between the supply and the LT3061 input also helps stabilize the application; as little as 0.1 to 0.5 suffices. This impedance dampens the LC tank circuit at the expense of dropout voltage. A better alternative is to use higher ESR tantalum or electrolytic capacitors at the LT3061 input in place of ceramic capacitors. 3061fb For more information www.linear.com/LT3061 15 LT3061 Series APPLICATIONS INFORMATION Overload Recovery Like many IC power regulators, the LT3061 has safe operating area protection. The safe area protection decreases current limit as input-to-output voltage increases and keeps the power transistor inside a safe operating region for all values of input-to-output voltage. The protective design provides some output current at all values of input-tooutput voltage up to the device breakdown. When power is first applied, as input voltage rises, the output follows the input, allowing the regulator to start up into very heavy loads. During start-up, as the input voltage is rising, the input-to-output voltage differential is small, allowing the regulator to supply large output currents. With a high input voltage, a problem can occur wherein removal of an output short will not allow the output to recover. The problem occurs with a heavy output load when the input voltage is high and the output voltage is low. Common situations include immediately after the removal of a short-circuit or if the shutdown pin is pulled high after the input voltage has already been turned on. The load line for such a load may intersect the output current curve at two points. If this happens, there are two stable output operating points for the regulator. With this double intersection, the input power supply may need to be cycled down to zero and brought up again to make the output recover. Thermal Considerations The power handling capability of the device will be limited by the maximum rated junction temperature (125C for LT3061E, LT3061I or 150C for LT3061MP, LT3061H). Two components comprise the power dissipated by the device: 1. Output current multiplied by the input/output voltage differential: IOUT * (VIN - VOUT), and 2. GND pin current multiplied by the input voltage: IGND * VIN 16 GND pin current is determined using the GND Pin Current curves in the Typical Performance Characteristics section. Power dissipation will be equal to the sum of the two components listed above. The LT3061 regulator has internal thermal limiting that protects the device during overload conditions. For continuous normal conditions, the maximum junction temperature of 125C (E-grade, I-grade) or 150C (MP-grade, H-grade) must not be exceeded. Carefully consider all sources of thermal resistance from junction to ambient including other heat sources mounted in proximity to the LT3061. The undersides of the LT3061 packages have exposed metal from the lead frame to the die attachment. The package allows heat to directly transfer from the die junction to the printed circuit board metal to control maximum operating junction temperature. The dual-in-line pin arrangement allows metal to extend beyond the ends of the package on the topside (component side) of a PCB. Connect this metal to GND on the PCB. The multiple IN and OUT pins of the LT3061 also assist in spreading heat to the PCB. For surface mount devices, heat sinking is accomplished by using the heat spreading capabilities of the PC board and its copper traces. Copper board stiffeners and plated through-holes can also be used to spread the heat generated by power devices. Tables 2 and 3 list thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on a 4 layer FR-4 board with 1oz solid internal planes and 2oz top/bottom external trace planes with a total board thickness of 1.6mm. The four layers were electrically isolated with no thermal vias present. PCB layers, copper weight, board layout and thermal vias will affect the resultant thermal resistance. For more information on thermal resistance and high thermal conductivity test boards, refer to JEDEC standard JESD51, notably JESD51-12 and JESD51-7. Achieving low thermal resistance necessitates attention to detail and careful PCB layout. 3061fb For more information www.linear.com/LT3061 LT3061 Series APPLICATIONS INFORMATION Table 2. Measured Thermal Resistance for DFN Package COPPER AREA TOPSIDE* BACKSIDE (mm2) (mm2) BOARD AREA (mm2) THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 2500 2500 2500 38C/W 1000 2500 2500 38C/W 225 2500 2500 40C/W 100 2500 2500 45C/W *Device is mounted on topside Table 3. Measured Thermal Resistance for MSOP Package COPPER AREA TOPSIDE* BACKSIDE (mm2) (mm2) 2500 BOARD AREA (mm2) THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 2500 29C/W 2500 1000 2500 2500 30C/W 225 2500 2500 32C/W 100 2500 2500 45C/W *Device is mounted on topside Calculating Junction Temperature Example: Given an output voltage of 2.5V, an input voltage range of 12V 5%, an output current range of 0mA to 50mA and a maximum ambient temperature of 85C, what will the maximum junction temperature be? The power dissipated by the device equals: IOUT(MAX) * (VIN(MAX)-VOUT) + IGND * VIN(MAX) where, Using a DFN package, the thermal resistance will be in the range of 38C/W to 45C/W depending on the copper area. So the junction temperature rise above ambient will be approximately equal to: 0.518W * 45C/W = 23.3C The maximum junction temperature equals the maximum ambient temperature plus the maximum junction temperature rise above ambient or: TJMAX = 85C + 23.3C = 108.3C Output Discharge The LT3061 includes a low resistance medium voltage NMOS device which rapidly discharges the output voltage if the part is put in shutdown mode. For a 2.9V output with a 10F decoupling capacitor, this NMOS discharges the output to 290mV in 750s if SHDN is driven low. Control circuitry drives the gate of the NMOS high if either the SHDN pin or the IN pin are driven low. In the case where the IN pin is driven to ground, the NMOS rapidly discharges the OUT pin to the threshold voltage of the NMOS, about 800mV. From 800mV, the external load will continue to discharge the OUT pin at a reduced rate. The control circuitry implements protection features which allow the OUT pin to be driven from -1V to 20V without damaging the LT3061. Current limit foldback for output voltages greater than 6V protects the NMOS pull-down, but increases discharge time for higher output voltages. 4.0 VIN(MAX) = 12.6V IGND at (IOUT = 50mA, VIN = 12V) = 1mA So, P = 50mA * (12.6V - 2.5V) + 1mA * 12.6V = 0.518W OUTPUT DISCHARGE TIME (ms) IOUT(MAX) = 50mA COUT = 10F 3.5 VIN = VOUT +1V 3.0 2.5 2.0 1.5 OUTPUT DISCHARGE FOLDBACK STARTS 1.0 0.5 0 0 2 4 6 8 10 12 14 16 18 20 OUTPUT VOLTAGE (V) 3061 F07 Figure 7. Discharge Time vs Output Voltage 3061fb For more information www.linear.com/LT3061 17 LT3061 Series APPLICATIONS INFORMATION The LT3061 incorporates several protection features that make it ideal for use in battery-powered circuits. In addition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the device also protects against reverse-input voltages and reverse output-to-input voltages. Current limit protection and thermal overload protection protect the device against current overload conditions at the output of the device. The typical thermal limit temperature is 165C. For normal operation, do not exceed a junction temperature of 125C (LT3061E, LT3061I) or 150C (LT3061MP, LT3061H). The LT3061 IN pin withstands reverse voltages of 50V. The device limits current flow to less than 1mA (typically less than 250A) and no negative voltage appears at OUT. The device protects both itself and the load against batteries that are plugged in backwards. The SHDN pin cannot be driven below GND unless tied to the IN pin. If the SHDN pin is driven below GND while IN is powered, the output will turn on. SHDN pin logic cannot be referenced to a negative rail. Several different input/output conditions can occur, some temporarily until the output capacitor is discharged by the LT3061. The output voltage may be held up temporarily or otherwise while the input is pulled to ground, pulled to some intermediate voltage or left open-circuit. Current flow back into the OUT pin follows the curve shown in Figure 8. If the LT3061's IN pin is forced below the OUT pin or the OUT pin is pulled above the IN pin, regardless of the state of the SHDN pin, input current typically drops to less than 3A. If IN is pulled near 0V, the output discharge pull-down NMOS turns on, regardless of the state of the SHDN pin. The gate drive for the pull-down is supplied by the output voltage. 50 VIN = VSHDN = 2.1V 45 VADJ = VOUT 40 OUTPUT CURRENT (A) Protection Features 35 30 25 20 15 10 The LT3061 incurs no damage if the ADJ pin is pulled above or below ground by 50V. If the input is left open circuit or grounded, the ADJ pin performs like a large resistor (typically 30k) in series with a diode when pulled above or below ground. 18 5 0 0 2 4 6 8 10 12 14 16 18 20 VOUT (V) 3061 F08 Figure 8. Reverse Output Current 3061fb For more information www.linear.com/LT3061 LT3061 Series PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LT3061#packaging for the most recent package drawings. DCB Package 8-Lead Plastic DFN (2mm x 3mm) (Reference LTC DWG # 05-08-1718 Rev A) 0.70 0.05 1.35 0.05 3.50 0.05 1.65 0.05 2.10 0.05 PACKAGE OUTLINE 0.25 0.05 0.45 BSC 1.35 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R = 0.115 TYP R = 0.05 5 TYP 2.00 0.10 (2 SIDES) 0.40 0.10 8 1.35 0.10 1.65 0.10 3.00 0.10 (2 SIDES) PIN 1 NOTCH R = 0.20 OR 0.25 x 45 CHAMFER PIN 1 BAR TOP MARK (SEE NOTE 6) (DCB8) DFN 0106 REV A 4 0.200 REF 1 0.23 0.05 0.45 BSC 0.75 0.05 1.35 REF 0.00 - 0.05 BOTTOM VIEW--EXPOSED PAD NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 3061fb For more information www.linear.com/LT3061 19 LT3061 Series PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LT3061#packaging for the most recent package drawings. MS8E Package 8-Lead Plastic MSOP, Exposed Die Pad (Reference LTC DWG # 05-08-1662 Rev K) BOTTOM VIEW OF EXPOSED PAD OPTION 1.88 (.074) 1 1.88 0.102 (.074 .004) 0.29 REF 1.68 (.066) 0.889 0.127 (.035 .005) 0.05 REF 5.10 (.201) MIN DETAIL "B" CORNER TAIL IS PART OF DETAIL "B" THE LEADFRAME FEATURE. FOR REFERENCE ONLY NO MEASUREMENT PURPOSE 1.68 0.102 3.20 - 3.45 (.066 .004) (.126 - .136) 8 3.00 0.102 (.118 .004) (NOTE 3) 0.65 (.0256) BSC 0.42 0.038 (.0165 .0015) TYP 8 7 6 5 0.52 (.0205) REF RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 3.00 0.102 (.118 .004) (NOTE 4) 4.90 0.152 (.193 .006) DETAIL "A" 0 - 6 TYP GAUGE PLANE 0.53 0.152 (.021 .006) DETAIL "A" 1 2 3 4 1.10 (.043) MAX 0.86 (.034) REF 0.18 (.007) SEATING PLANE 0.22 - 0.38 (.009 - .015) TYP 0.65 (.0256) NOTE: BSC 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL NOT EXCEED 0.254mm (.010") PER SIDE. 20 0.1016 0.0508 (.004 .002) MSOP (MS8E) 0213 REV K 3061fb For more information www.linear.com/LT3061 LT3061 Series REVISION HISTORY REV DATE DESCRIPTION A 08/16 Add 3.3V/5V fixed voltage options B 11/17 Modified Guaranteed Dropout Voltage curve PAGE NUMBER 1-22 5 3061fb Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license granted by implication or otherwise under any patent or patent rights of Analog Devices. For ismore information www.linear.com/LT3061 21 LT3061 Series TYPICAL APPLICATION 1.8V Low Noise Regulator IN VIN 2.2V 118k 1% LT3061 1F VOUT 1.8V 100mA OUT SHDN GND 10F ADJ 59k 1% BYP 0.01F 3061 TA02 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1761 100mA, Low Noise LDO 300mV Dropout Voltage, Low Noise: 20VRMS , VIN = 1.8V to 20V, ThinSOTTM Package LT1762 150mA, Low Noise LDO 300mV Dropout Voltage, Low Noise: 20VRMS , VIN = 1.8V to 20V, MS8 Package LT1763 500mA, Low Noise LDO 300mV Dropout Voltage, Low Noise: 20VRMS , VIN = 1.8V to 20V, SO8 Package LT1962 300mA, Low Noise LDO 270mV Dropout Voltage, Low Noise: 20VRMS , VIN = 1.8V to 20V, MS8 Package LT1964 200mA, Low Noise, Negative LDO 340mV Dropout Voltage, Low Noise 30VRMS , VIN = -1.8V to -20V, ThinSOT and 3mm x 3mm DFN-8 Packages LT3008 20mA, 45V, 3A IQ Micropower LDO 300mV Dropout Voltage, Low IQ: 3A, VIN = 2V to 45V, VOUT = 0.6V to 44V; ThinSOT and 2mm x 2mm DFN-6 Packages 280mV Dropout Voltage, Low IQ: 3A, VIN = 1.6V to 20V, 2mm x 2mm DFN-6 and SC70 Packages LT3009 20mA, 3A IQ Micropower LDO LT3050 100mA, Low Noise Linear Regulator with 340mV Dropout Voltage, Low Noise: 30VRMS , VIN: 1.6V to 45V, VOUT: 0.6V to 44.5V, Programmable Precision Current Limit: 5%, Programmable Minimum IOUT Monitor, Output Current Precision Current Limit and Diagnostic Monitor, Fault Indicator, Reverse Protection; 12-Lead 2mm x 3mm DFN and MSOP Packages. Functions. LT3060 45V VIN, Micropower, Low Noise, 100mA Low Dropout Linear Regulator Input Voltage Range: 1.6V to 45V, Quiescent Current: 40A, Dropout Voltage: 300mV, Low Noise: 30VRMS (10Hz to 100kHz), Adjustable Output: VREF = 600mV, 8-Lead 2mm x 2mm DFN and 8-Lead ThinSOT LT3062 45V VIN, Micropower, Low Noise, 200mA Low Dropout Linear Regulator Input Voltage Range: 1.6V to 45V, Quiescent Current: 45A, Dropout Voltage: 300mV, Low Noise: 30VRMS (10Hz to 100kHz), Adjustable Output: 600mV to 40V, 8-Lead MSOP and 2mm x 3mm DFN LT3063 45V VIN, Micropower, Low Noise, 200mA Low Dropout Linear Regulator with Active Output Discharge Active Output Discharge, Input Voltage Range: 1.6V to 45V, Quiescent Current: 45A, Dropout Voltage: 300mV, Low Noise: 30VRMS (10Hz to 100kHz), Adjustable Output: 600mV to 19V, 8-Lead MSOP and 2mm x 3mm DFN LT3082 200mA, Parallelable, Single Resistor, Low Dropout Linear Regulator Outputs May Be Paralleled for Higher Output, Current or Heat Spreading, Wide Input Voltage Range: 1.2V to 40V Low Value Input/Output Capacitors Required: 0.22F, Single Resistor Sets Output Voltage Initial Set Pin Current Accuracy: 1%, Low Output Noise: 40VRMS (10Hz to 100kHz) Reverse-Battery Protection, Reverse-Current Protection; 8-Lead SOT-23, 3-Lead SOT-223 and 8-Lead 3mm x 3mm DFN Packages LT3085 500mA, Parallelable, Low Noise, Low Dropout Linear Regulator 275mV Dropout Voltage (2-Supply Operation), Low Noise: 40VRMS, VIN: 1.2V to 36V, VOUT: 0V to 35.7V, Current-Based Reference with 1-Resistor VOUT Set, Directly Parallelable (No Op Amp Required), Stable with Ceramic Capacitors; MS8E and 2mm x 3mm DFN-6 Packages LT3092 200mA 2-Terminal Programmable Current Source Programmable 2-Terminal Current Source, Maximum Output Current: 200mA Wide Input Voltage Range: 1.2V to 40V, Resistor Ratio Sets Output Current Initial Set Pin Current Accuracy: 1%, Current Limit and Thermal Shutdown Protection Reverse-Voltage Protection, Reverse-Current Protection; 8-Lead SOT-23, 3-Lead SOT-223 and 8-Lead 3mm x 3mm DFN Packages 22 3061fb LT 1117 REV B * PRINTED IN USA For more information www.linear.com/LT3061 www.linear.com/LT3061 ANALOG DEVICES, INC. 2014