19-6257; Rev 0; 3/12 EVALUATION KIT AVAILABLE MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector General Description Benefits and Features The MAX14626 current loop protector features a currentlimit switch to prevent damage to the sensor devices due to faulty current loop conditions. The current-limit switch features a 25I (typ) on-resistance and operates from a +2.3V to +36V input voltage range. The accurate current limit is set to 30mA, making the part ideal for protecting the sensor reading devices. S High Performance Low On-Resistance 25I (typ) Accurate Q10% Current Limit +2.3V to +40V Wide Supply Voltage Range Low Operating Current Ultra-Low Temperature Coefficient The MAX14626 handles an overcurrent event in a continuous current-limit mode. Additional safety features include thermal shutdown to prevent overheating and reverse-input blocking to protect from being reverse connected into the sensor. S Robust Protection for Sensors Avoids Power Dissipation Issues Compared to Discrete Solutions Thermal Shutdown Reverse Input Protection The device is available in a tiny 6-pin (3mm x 3mm), TDFN exposed pad package and is specified over the -40NC to +85NC extended temperature range. S Saves Space in Compact Systems Eliminates Need for Discrete PTC Poly Switch, Zener Diodes, and Resistors 3mm x 3mm, 6-Pin TDFN Package Applications Industrial Current Loop Control Ordering Information appears at end of data sheet. For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX14626.related. Typical Operating Circuit 4-20mA CURRENT SENSOR (4-20mA) CURRENT MAX14626 IN REF SUPPLY OUT CONTROL AND PROTECTION RLOAD IA ADC CURRENT LIMIT GATE CONTROL GND Maxim Integrated Products1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) IN to GND ...............................................................-40V to +40V OUT to GND ......................................................... -0.3V to +40V Current into IN................................................. Internally Limited Current into OUT...............................................................100mA Continuous Power Dissipation (TA = +70NC) TDFN (derate 23.8mW/NC above +70NC)................1904.8mW Operating Temperature Range......................... -40NC to +125NC Maximum Junction Temperature......................................+150NC Storage Temperature Range............................. -65NC to +150NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. PACKAGE THERMAL CHARACTERISTICS (Note 1) TDFN Junction-to-Ambient Thermal Resistance (BJA).............. 42NC/W Junction-to-Case Thermal Resistance (BJC)..................... 9NC/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. DC ELECTRICAL CHARACTERISTICS (IIN = 50FA to 24mA, TA = -40NC to +85NC, RLOAD = 25I to 1kI, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD = 250I, and TA = +25NC.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 2.3 V 36 V 2.8 V 56 FA 65 FA 0.01 0.3 FA 25 45 I 30 33 mA SUPPLY VOLTAGE Operating Start Voltage Operating IN Voltage VIN_ST IIN = 20FA VIN Operating IN to OUT Drop Voltage IIN = 24mA Quiescent Current (Normal Mode: 4-20mA) IQ RLOAD P 250I Quiescent Current (CurrentLimit Mode: Current > 25mA) IQ IOUT = 30mA, VIN = 5V, RLOAD = 25I 40 Reverse Current IREV VIN = -36V, VOUT = 0V, current into OUT IN to OUT Switch On-Resistance RON VIN = 4V, IOUT = 16mA Forward Current Limit ILIM VIN = 36V Turn-On Time tSS VIN = 3V, time from VIN applied to VOUT = 90% of VIN (Note 3) 10 Fs Turn-Off Time tOFF Time from thermal shutdown (Note 3) 20 Fs tLIM Input current source from 20mA to 50mA (Note 4) 50 Fs Input current source from 0mA to 50mA 50 % 2mA P DC IIN P 24mA, DIIN = 1mAP-P at 1kI > 10 kHz 27 DYNAMIC Current-Limit Reaction Time Current-Limit Overshoot Voltage Input Small Signal Bandwidth BW Maxim Integrated Products2 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector DC ELECTRICAL CHARACTERISTICS (continued) (IIN = 50FA to 24mA, TA = -40NC to +85NC, RLOAD = 25I to 1kI, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD = 250I, and TA = +25NC.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS THERMAL PROTECTION Thermal Shutdown Thermal-Shutdown Hysteresis +150 NC 20 NC Note 2: All devices are 100% production tested at TA = +25NC, unless otherwise noted. Limits over the -40NC to +85NC operating temperature range are guaranteed by design. Note 3: Turn-on time and turn-off time are defined as the difference in the time between when the output voltage crosses 10% and 90% of the final output voltage. Note 4: Input current source can support voltage up to +40V (absolute maximum). Current reaction time is defined as the settling time of the output current after a fault event. Typical Operating Characteristics (VIN = 24V, IIN = 10mA, RLOAD = 250I, unless otherwise noted. Typical values are at TA = +25NC.) QUIESCENT IQ vs. IIN 80 60 50 40 30 70 60 40 30 20 20 10 10 0 0 0 4 8 12 16 20 VIN (V) 24 28 32 36 RL = 250I 50 90 80 QUIESCENT IQ (A) 70 90 QUIESCENT IQ (A) QUIESCENT IQ (A) 80 QUIESCENT IQ vs. TEMPERATURE 100 MAX14626 toc02 MAX14626 toc01 NO LOAD 90 100 70 60 50 0 5 10 IIN (mA) 15 IIN = 10mA IIN = 20mA 40 30 20 RL = 100I MAX14626 toc03 QUIESCENT IQ vs. VIN 100 IIN = 4mA IIN = 0mA 10 20 0 -40 -25 -10 5 20 35 50 65 80 95 110 TEMPERATURE (C) Maxim Integrated Products3 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector Typical Operating Characteristics (continued) (VIN = 24V, IIN = 10mA, RLOAD = 250I, unless otherwise noted. Typical values are at TA = +25NC.) ON-RESISTANCE vs. TEMPERATURE ON-RESISTANCE (I) 40 30 VIN = +5V VIN = +24V 20 VIN = +12V MAX14626 toc06 MAX14626 toc05 VIN = +2.36V 40 REVERSE CURRENT (nA) IOUT = 10mA IIN 0mA TO 20mA REVERSE CURRENT vs. VOUT 50 MAX14626 toc04 50 VOUT 2V/div 1) 30 20 10 10 0 0 IIN 10mA /div 1) CH1 VOUT 2V 100s 2) 2) CH4 LIN 100mV 100s -40 -25 -10 5 20 35 50 65 80 95 110 0 10 TEMPERATURE (C) 20 100s/div 40 30 VOUT (V) SOFT CURRENT LIMIT: IIN 15mA TO 35mA FAULT RESPONSE (SHORT TO WIRE): IIN 10mA TO 100mA MAX14626 toc07 MAX14626 toc08 VOUT 1) 5V/div VOUT 5V/div 1) IIN IIN 10mA /div 2) 1) CH1 VOUT 5V 100s 2) CH4 LIN 100mV 100s 100s/div 2) 20mA /div 1) CH1 VOUT 5V 50s 2) CH4 LIN 100mV 50s 50s/div Maxim Integrated Products4 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector GND I.C. TOP VIEW OUT Pin Configuration 6 5 4 MAX14626 *EP 2 3 I.C. IN 1 I.C. + TQFN *CONNECT EP TO GND Pin Description PIN NAME 1 IN Power Input FUNCTION 2, 3, 4 I.C. Internally Connected. Connect I.C. to GND. 5 GND Ground 6 OUT Switch Output -- EP Exposed Pad. Connect EP to GND. Connect to a large ground plane to maximize thermal performance. Not intended as an electrical connection point. Maxim Integrated Products5 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector Functional Diagram MAX14626 IN REF SUPPLY OUT CONTROL AND PROTECTION CURRENT LIMIT GATE CONTROL GND Detailed Description Thermal Shutdown The MAX14626 current loop protector features a currentlimit switch to prevent damage to the sensor devices due to faulty current loop conditions. The current-limit switch features a 25I (typ) on-resistance and operates from a +2.3V to +36V input voltage range. The accurate current limit is set to 30mA, making the part ideal for protecting the sensor reading devices. The device enters thermal shutdown when the die temperature exceeds +150NC (typ). In thermal shutdown, the internal FETs are turned off. When the die temperature drops by 20NC, the device turns back on automatically. The MAX14626 handles an overcurrent event in a continuous current-limit mode. Additional safety features include thermal shutdown to prevent overheating and reverse input blocking to protect from being reverse connected into the sensor. Reverse Input Protection The device features reverse input protection to protect the downstream sensor. When a reverse input voltage is detected, control circuitry turns off the internal FET and isolates the output from the input. Applications Information Figure 1 shows the device in a 4-20mA current loop sensor application. Exposed Pad and Layout Concerns Connect the exposed pad to a large ground plane to maximize thermal performance. The exposed pad is not intended as an electrical connection point. To optimize the switch response time to output shortcircuit conditions, it is very important to keep all traces as short as possible to reduce the effect of undesirable parasitic inductance. Maxim Integrated Products6 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector VOLTAGE SPIKE AND RF SUPRESSION SENSOR (4-20mA) CURRENT +INPUT MAX14626 RLOAD = 250I IA ADC IA ADC -INPUT ANALOG INPUT MODULE + DC SUPPLY 19.2V TO 32V CURRENT LOOP - VOLTAGE SPIKE AND RF SUPRESSION +INPUT MAX14626 RLOAD = 250I -INPUT ANALOG INPUT MODULE Figure 1. 4-20mA Current Loop Sensor Application Ordering Information PART TEMP RANGE PINPACKAGE TOP MARK MAX14626ETT+T -40NC to +85NC 6 TDFN-EP* AVF +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. LAND PATTERN 6 TDFN T633+2 21-0137 90-0058 Chip Information PROCESS: BiCMOS Maxim Integrated Products7 MAX14626 High-Voltage Reverse-Input-Capable 4-20mA Current Loop Protector Revision History REVISION NUMBER REVISION DATE 0 3/12 DESCRIPTION Initial release PAGES CHANGED -- Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 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