LSM-10A D12 Models www.murata-ps.com Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters NOT RECOMMENDED FOR NEW DESIGNS Typical Unit FEATURES PRODUCT OVERVIEW Step-down, wide buck regulators for new distributed 12V power architectures 12V input (10.8-13.2V range) 0.75 to 5VOUT @10A Voltage-selectable "T" version Non-isolated, fixed-frequency, synchronous-rectifier topology Tape and reel SMT package 1.25% setpoint accuracy Efficiencies to 96% @ 10 Amps Stable no-load operation Remote on/off control Sense pin and output voltage trim No derating to +65C with 100 lfm UL/IEC/EN60950-1 certification pending EMC compliant LSM Series D12 SMT's (surface-mount packages) are ideal building blocks for emerging, on-board power-distribution schemes in which isolated 12V buses deliver power to any number of nonisolated, step-down buck regulators. LSM D12 DC/DC's accept a 12V input (10.8V to 13.2V input range) and convert it, with the highest efficiency in the smallest space, to a 0.75, 1, 1.2, 1.5, 1.8, 2, 2.5, 3.3 or 5 Volt output fully rated at 10 Amps. LSM D12's are ideal point-of-use/load power processors. They typically require no external components. Their surface-mount packages occupy a mere 1.3" x 0.53" (33.0 x 13.5mm), and are only 0.34 inches (8.6mm) high. The LSM's best-in-class power density is achieved with a fully synchronous, fixedfrequency, buck topology that also delivers: high efficiency (96% for 5VOUT models), low noise (50mVp-p typ.), tight line/load regulation (0.1%/0.25% max.), quick step response (100sec), stable no-load operation, and no output reverse conduction. The fully functional LSM's feature output overcurrent detection, continuous short-circuit protection, over-temperature protection, a remote on/off control pin (pull low to disable), an output-voltage trim function, and a sense pin. High efficiency enables the LSM D12's to deliver rated output currents of 10 Amps at ambient temperatures to +65C with 100 lfm air flow. If your new system boards call for three or more supply voltages, check out the economics of on-board 12V distributed power. If you don't need to pay for multiple isolation barriers, Murata Power Solutions' non-isolated LSM D12 SMT's will save you money. +OUTPUT (4) +INPUT (2) +SENSE (6) COMMON (3) COMMON (3) CURRENT SENSE VCC ON/OFF CONTROL (1) PWM CONTROLLER REFERENCE & ERROR AMP VOUT TRIM (5) Typical topology is shown Figure 1. Simplified Schematic For full details go to www.murata-ps.com/rohs www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 1 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters PERFORMANCE SPECIFICATIONS SUMMARY AND ORDERING GUIDE Output Models VOUT (Volts) IOUT (Amps) LSM-0.8/10-D12 LSM-1/10-D12 LSM-1.2/10-D12 LSM-1.5/10-D12 LSM-1.8/10-D12 LSM-2/10-D12 LSM-2.5/10-D12 LSM-3.3/10-D12 LSM-5/10-D12 LSM-T/10-D12 0.8 1 1.2 1.5 1.8 2 2.5 3.3 5 0.75-5 10 10 10 10 10 10 10 10 10 10 R/N (mVp-p) Input Regulation (Max.) Typ. Max. Line Load VIN Nom. (Volts) 45 50 50 50 50 50 50 50 75 50 60 75 85 75 75 75 75 75 100 75 0.1% 0.1% 0.2% 0.1% 0.1% 0.1% 0.1% 0.1% 0.3% 0.1% 0.375% 0.25% 0.65% 0.25% 0.25% 0.25% 0.25% 0.7% 0.95% 0.25% 12 12 12 12 12 12 12 12 12 12 Typical at TA = +25C under nominal line voltage and full-load conditions, unless noted. All models are tested and specified with external 22F tantalum input and output capacitors. These capacitors are necessary to accommodate our test equipment and may not be required to achieve specified performance in your applications. See I/O Filtering and Noise Reduction. Ripple/Noise (R/N) is tested/specified over a 20MHz bandwidth and may be reduced with external filtering. See I/O Filtering and Noise Reduction for details. Efficiency Range (Volts) IIN (mA/A) Min. Typ. Typ. Package (Case, Pinout) 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10.8-13.2 10-14 30/0.84 35/1.02 40/1.19 50/1.47 55/1.75 55/1.9 60/2.3 70/3 85/4.5 100/6.5 80.5% 83% 85% 86.5% 88% 89% 90% 92% 93.5% 92% 82.5% 85% 87% 88.5% 90% 91% 92.5% 94% 96% 93% 85% 86% 88% 89.5% 90.5% 91.5% 92% 93.5% 95.5% -- C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 Full Load 1/2 Load These devices have no minimum-load requirements and will regulate under no-load conditions. Regulation specifications describe the output-voltage deviation as the line voltage or load is varied from its nominal/midpoint value to either extreme. Nominal line voltage, no-load/full-load conditions. LSM-T/10-D12 specifications are given at VOUT = 5V, full load. PART NUMBER STRUCTURE L SM - 1.8 / 10 - D12 - C Output Configuration: L = Unipolar Low Voltage Non-Isolated SMT Nominal Output Voltage: 0.8, 1, 1.2, 1.5, 1.8, 2, 2.5, 3.3, 5 Volts or "T" voltage selectable RoHS-6 compliant* Input Voltage: D12 = 12V nominal Maximum Rated Output Current in Amps * Contact Murata Power Solutions for availability. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 2 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters MECHANICAL SPECIFICATIONS 1.36 (34.54) I/O Connections Pin Function P63 1 On/Off Control 2 +Input 3 Common 4 +Output 5 VOUT Trim 6 +Sense 0.55 (13.97) 0.60 (15.24) 0.010 (0.254) 0.570 (14.48) 3 EQ. SP. @ 0.190 (4.83) 0.310 (7.87) 3 0.062 (1.57) 4 5 0.375 (9.53) 0.052 (1.32) 6 2 1 0.112 TYP. (2.84) 0.049 (1.24) BOTTOM VIEW LSM WITH REMOVEABLE HEAT SHIELD FOR HIGH TEMPERATURE SOLDER ( ) 0.052 (1.32) CAUTION PRESS TO REMOVE THE HEAT SHIELD AFTER THE SOLDER PROCESS %1 30 490 CAUTION PRESS TO REMOVE THE HEAT SHIELD AFTER THE SOLDER PROCESS "/44/- 6)%7 %1 30 NOTCH IN SHELL INDICATES PIN ONE DIMENSIONS ARE IN INCHES (MM) Case C45 490 Refer to the last page for Tape and Reel information. 3-4 #/00%2 ,%!$3 #/0,!.!2 0.047 (1.19) 2%#/--%.$%$ 0!$ ,!9/54 2ECOMMENDED 0AD 3IZE X X www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 3 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Performance/Functional Specifications Typical @ TA = +25C under nominal line voltage and full-load conditions unless noted. Input Input Voltage Range Input Current: Normal Operating Conditions Inrush Transient Standby/Off Mode Output Short-Circuit Condition Input Reflected Ripple Current Input Filter Type Overvoltage Protection Reverse-Polarity Protection Undervoltage Shutdown On/Off Control See Ordering Guide See Ordering Guide 0.08A2 sec 1.5mA 12-40mA average (model dependent) 40mAp-p Capacitive None None None (except 8V LSM-T/10-D12) On = open (internal pull-up to +VIN) Off = 0 to +0.4V (1mA max.) Output VOUT Accuracy (50% load) Minimum Loading Maximum Capacitive Load VOUT Trim Range Ripple/Noise (20MHz BW) 1.25% max. (2% "T" version, 50% load) No load 1000F (low ESR, OSCON) 10% (0.8V not trimmable) See Ordering Guide Total Accuracy 3% over line/load/temperature Efficiency See Ordering Guide Overcurrent Detection and Short-Circuit Protection: Current-Limiting Detection Point 17 Amps Short-Circuit Detection Point 98% of VOUT set SC Protection Technique Hiccup with auto recovery Short-Circuit Current 120-400mA average (model dependent) Output noise may be further reduced with the installation of additional external output filtering. See I/O Filtering and Noise Reduction. MTBF's are calculated using Telcordia SR-332(Bellcore), ground fixed, TA = +25C, full power, natural convection, +67C pcb temperature. Input Ripple Current is tested/specified over a 5-20MHz bandwidth with an external 33F input capacitor and a simulated source impedance of 220F and 12H. See I/O Filtering, Input Ripple Current and Output Noise for details. On/Off Control for LSM-T/10-D12 only: Positive Logic: On = pin open or to +4V max., Off = pin grounded or 0 to +0.4V max. Shutdown current is 3A sink. The Output Voltage Range for the LSM-T/10-D12 is +0.75V to +5V, user selectable. LSM-T/10-D12 Overcurrent and Short-circuit specs: Current limit 25 Amps Short Circuit Current 600mA Absolute Maximum Ratings Input Voltage: Continuous or transient 15 Volts On/Off Control (Pin 1) +VIN (+4V for "T" version) Input Reverse-Polarity Protection None Output Overvoltage Protection None Output Current Current limited. Devices can withstand sustained output short circuits without damage. Storage Temperature -40 to +125C Lead Temperature See Reflow Solder Profile These are stress ratings. Exposure of devices to any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those listed in the Performance/Functional Specifications Table is not implied. Dynamic Characteristics Transient Response (50% load step) Start-Up Time: VIN to VOUT and On/Off to VOUT Switching Frequency: 0.8V, 1V/1.2V Models 1.5V/1.8V, 2V Models 2.5V, 3.3V, 5V Models LSM-T/10-D12 115sec to 2% of final value 75msec for VOUT = 1V and 0.8V 50msec for VOUT = 1.2V to 5V 105/120kHz 10% 160/177kHz 10% 195kHz 10% 230kHz 30kHz Environmental Calculated MTBF 2.3-1.8 million hours (1VOUT to 5VOUT) Operating Temperature: (Ambient) Without Derating (100 lfm) -40 to +48/64C (model dependent) With Derating See Derating Curves Thermal Shutdown +115C (110 to 125C) Physical Dimensions 1.3" x 0.53" x 0.34" (33.02 x 13.46 x 8.64 mm) Pin Dimensions/Material 0.112" x 0.062" (2.84 x 1.57mm) rectangular copper with gold plate over nickel underplate Weight 0.28 ounces (7.8g) Flamability Rating UL94V-0 EMI Conducted and radiated FCC part 15, EN55022 (may require external filter) Safety UL/cUL/IEC/EN 60950-1, CSA-C22.2 No. 234 All models are tested and specified with external 22F tantalum input and output capacitors. These capacitors are necessary to accommodate our test equipment and may not be required to achieve specified performance in your applications. All models are stable and regulate within spec under no-load conditions. See Technical Notes and Performance Curves for details. The On/Off Control (pin 1) is designed to be driven with open-collector logic or the application of appropriate voltages (referenced to Common, pin 3). Applying a voltage to On/Off Control when no input voltage is applied to the converter may cause permanent damage. TECHNICAL NOTES I/O Filtering and Noise Reduction All models in the LSM D12 Series are tested and specified with external 22F tantalum input and output capacitors. These capacitors are necessary to accommodate our test equipment and may not be required to achieve desired performance in your application. The LSM D12's are designed with high-quality, high-performance internal I/O caps, and will operate within spec in most applications with no additional external components. In particular, the LSM D12's input capacitors are specified for low ESR and are fully rated to handle the units' input ripple currents. Similarly, the internal output capacitors are specified for low ESR and full-range frequency response. As shown in the Performance Curves, removal of the external 22F tantalum output caps has minimal effect on output noise. In critical applications, input/output ripple/noise may be further reduced using filtering techniques, the simplest being the installation of external I/O caps. External input capacitors serve primarily as energy-storage devices. They minimize high-frequency variations in input voltage (usually caused by IR drops in conductors leading to the DC/DC) as the switching converter draws pulses of current. Input capacitors should be selected for bulk capacitance (at appropriate frequencies), low ESR, and high rms-ripple-current ratings. The switching nature of modern DC/DC's requires that the dc input voltage source have low ac impedance at the frequencies of interest. Highly inductive source impedances can greatly affect system stability. Your specific system configuration may necessitate additional considerations. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 4 of 18 MDC_LSM10AD12_A01 Page 4 of 14 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters 4/ /3#),,/3#/0% #522%.4 02/"% ers are not internally fused. Therefore, if input fusing is mandatory, either a normal-blow or a fast-blow fuse with a value no greater than 20 Amps should be installed within the ungrounded input path to the converter. ).054 ,"53 6). #"53 #). As a rule of thumb however, we recommend to use a normal-blow or slow-blow fuse with a typical value of about twice the maximum input current, calculated at low line with the converters minimum efficiency. n #/--/. #). & %32 M7 K(Z K(Z #"53 & %32 M7 ,"53 ( ,3- 4 $ &ILTERS #). X & #"53 & ,"53 ( Safety Considerations LSM D12 SMT's are non-isolated DC/DC converters. In general, all DC/DC's must be installed, including considerations for I/O voltages and spacing/separation requirements, in compliance with relevant safety-agency specifications (usually UL/IEC/EN60950-1). Figure 2. Measuring Input Ripple Current Output ripple/noise (also referred to as periodic and random deviations or PARD) may be reduced below specified limits with the installation of additional external output capacitors. Output capacitors function as true filter elements and should be selected for bulk capacitance, low ESR, and appropriate frequency response. Any scope measurements of PARD should be made directly at the DC/DC output pins with scope probe ground less than 0.5" in length. +SENSE +OUTPUT 6 COPPER STRIP 4 C1 COMMON C2 SCOPE RLOAD 3 COPPER STRIP C1 = NA C2 = 22F TANTALUM LOAD 2-3 INCHES (51-76mm) FROM MODULE Figure 3. Measuring Output Ripple/Noise (PARD) All external capacitors should have appropriate voltage ratings and be located as close to the converters as possible. Temperature variations for all relevant parameters should be taken into consideration. The most effective combination of external I/O capacitors will be a function of your line voltage and source impedance, as well as your particular load and layout conditions. Our Applications Engineers can recommend potential solutions and discuss the possibility of our modifying a given device's internal filtering to meet your specific requirements. Contact our Applications Engineering Group for additional details. Input Fusing Most applications and or safety agencies require the installation of fuses at the inputs of power conversion components. LSM D12 Series DC/DC convert- In particular, for a non-isolated converter's output voltage to meet SELV (safety extra low voltage) requirements, its input must be SELV compliant. If the output needs to be ELV (extra low voltage), the input must be ELV. Input Overvoltage and Reverse-Polarity Protection LSM D12 SMT Series DC/DCs do not incorporate either input overvoltage or input reverse-polarity protection. Input voltages in excess of the specified absolute maximum ratings and input polarity reversals of longer than "instantaneous" duration can cause permanent damage to these devices. Start-Up Time The VIN to VOUT Start-Up Time is the interval between the time at which a ramping input voltage crosses the lower limit of the specified input voltage range and the fully loaded output voltage enters and remains within its specified accuracy band. Actual measured times will vary with input source impedance, external input capacitance, and the slew rate and final value of the input voltage as it appears to the converter. The On/Off to VOUT Start-Up Time assumes the converter is turned off via the On/Off Control with the nominal input voltage already applied to the converter. The specification defines the interval between the time at which the converter is turned on and the fully loaded output voltage enters and remains within its specified accuracy band. See Typical Performance Curves. Remote Sense LSM D12 SMT Series DC/DC converters offer an output sense function on pin 6. The sense function enables point-of-use regulation for overcoming moderate IR drops in conductors and/or cabling. Since these are non-isolated devices whose inputs and outputs usually share the same ground plane, sense is provided only for the +Output. The remote sense line is part of the feedback control loop regulating the converter's output. The sense line carries very little current and consequently requires a minimal cross-sectional-area conductor. As such, it is not a lowimpedance point and must be treated with care in layout and cabling. Sense lines should be run adjacent to signals (preferably ground), and in cable and/or discrete-wiring applications, twisted-pair or similar techniques should be used. To prevent high frequency voltage differences between VOUT and Sense, we recommend installation of a 1000pF capacitor close to the converter. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 5 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters The sense function is capable of compensating for voltage drops between the +Output and +Sense pins that do not exceed 10% of VOUT. [VOUT(+) - Common] - [Sense(+) - Common] 10%VOUT Power derating (output current limiting) is based upon maximum output current and voltage at the converter's output pins. Use of trim and sense functions can cause the output voltage to increase, thereby increasing output power beyond the LSM's specified rating. Therefore: ).054 /./&& #/.42/, ! 333$ 07- (VOUT at pins) x (IOUT) rated output power The internal 10.5 resistor between +Sense and +Output (see Figure 1) serves to protect the sense function by limiting the output current flowing through the sense line if the main output is disconnected. It also prevents output voltage runaway if the sense connection is disconnected. Note: If the sense function is not used for remote regulation, +Sense (pin 6) must be tied to +Output (pin 4) at the DC/DC converter pins. On/Off Control The On/Off Control pin may be used for remote on/off operation. LSM D12 Series DC/DC converters are designed so that they are enabled when the control pin is left open (open collector) and disabled when the control pin is pulled low (to less than +0.4V relative to Common). As shown in Figure 4, all models have an internal pull-up resistor. Dynamic control of the on/off function is best accomplished with a mechanical relay or open-collector/open-drain drive circuit (optically isolated if appropriate). The drive circuit should be able to sink appropriate current when activated and withstand appropriate voltage when deactivated. #/--/. Figure 4A. LSM-T10-D12 Driving the On/Off Control Input Power-up Sequencing If a controlled start-up of one or more LSM D12 Series DC/DC converters is required, or if several output voltages need to be powered-up in a given sequence, the On/Off control pin can be driven with an external open collector device as per Figure 5. ).054 K7 %84%2.!, /0%. #/,,%#4/2 ).054 #/--/. ).054 External Input Open: On/Off pin Low = DC/DC converter Off External Input Low: On/Off pin High = DC/DC converter On Figure 5. Driving the External Power-Up Open Collector /./&& #/.42/, #/--/. ON/OFF pin open: Logic High = DC/DC converter On ON/OFF pin <0.4V: Logic Low = DC/DC converter Off Figure 4. Driving the On/Off Control Pin with an Open-Collector Drive Circuit (All models except LSM-T/10-D12) Applying an external voltage to the On/Off Control pin when no input power is applied to the converter can cause permanent damage to the converter. The on/off control function, however, is designed such that the converter can be disabled (control pin pulled low) while input voltage is ramping up and then "released" once the input has stabilized (see also power-up sequencing). Leaving the input of the external circuit open during power-up will have the output of the DC/DC converter disabled. When the input to the external open collector is pulled low, the DC/DC converters output will be enabled. Output Overvoltage Protection LSM D12 SMT Series DC/DC converters do not incorporate output overvoltage protection. In the extremely rare situation in which the device's feedback loop is broken, the output voltage may run to excessively high levels (VOUT = VIN). If it is absolutely imperative that you protect your load against any and all possible overvoltage situations, voltage limiting circuitry must be provided external to the power converter. Output Overcurrent Detection Overloading the power converter's output for an extended time will invariably cause internal component temperatures to exceed their maximum ratings and eventually lead to component failure. High-current-carrying components such as inductors, FET's and diodes are at the highest risk. LSM D12 SMT Series DC/DC converters incorporate an output overcurrent detection and shutdown function that serves to protect both the power converter and its load. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 6 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters If the output current exceeds it maximum rating by typically 70% or if the output voltage drops to less than 98% of it original value, the LSM D12's internal overcurrent-detection circuitry immediately turns off the converter, which then goes into a "hiccup" mode. While hiccupping, the converter will continuously attempt to restart itself, go into overcurrent, and then shut down. Once the output short is removed, the converter will automatically restart itself. Output Voltage Trimming (Except "T" models--See "T" Trimming) Allowable trim ranges for each model in the LSM D12 SMT Series are 10%. The LSM-T/10-D12 has a user-selectable output range of +0.75V to +5V. Trimming is accomplished with either a trimpot or a single fixed resistor. The trimpot should be connected between +Output and Common with its wiper connected to the Trim pin as shown in Figure 6 below. The following trim equations can be starting points for selecting specific trim-resistor values. Recall, untrimmed devices are guaranteed to be 1.25% accurate. Adjustment beyond the specified adjustment range is not recommended. When using trim in combination with Remote Sense, the maximum rated power must not be exceeded (see Remote Sense). Trim Equations RT DOWN (k) = ).054 K7 4URNS ,/!$ RT DOWN (k) = #/--/. #/--/. -X A trimpot can be used to determine the value of a single fixed resistor which can then be connected, as shown in Figure 7, between the Trim pin and +Output to trim down the output voltage, or between the Trim pin and Common to trim up the output voltage. Fixed resistors should have absolute TCR's less than 100ppm/C to ensure stability. VO NOM - VO -X 1.46 VO - VO NOM -X X = 0.909 X = 2.49 X = 3.09 X = 4.12 RT UP (k) = 3.72 VO - VO NOM -X RT DOWN (k) = 7.5(VO - 0.8) VO NOM - VO -X RT UP (k) = 6 VO - VO NOM -X LSM-2.5/10-D12: X = 20 LSM-3.3/10-D12: X = 15 LSM-5/10-D12: X = 10 Note: Resistor values are in k. Accuracy of adjustment is subject to tolerances of resistors and factory-adjusted, initial output accuracy. VO = desired output voltage. VONOM = nominal output voltage. +OUTPUT Trim Down TRIM 4.64(VO - 0.8) RT UP (k) = LSM-1.5/10-D12: X = 13.3 LSM-1.8/10-D12: X = 16.9 LSM-2/10-D12: X = 15.4 Figure 6. Trim Connections Using a Trimpot +INPUT VO NOM - VO LSM-1/10-D12: LSM-1.1/10-D12: LSM-1.2/10-D12: LSM-1.3/10-D12: /54054 42)- 1.82(VO - 0.8) LOAD Note: LSM-0.8/10-D12 is not trimmable. Trim Up COMMON COMMON Note: Install either a fixed trim-up resistor or a fixed trim-down resistor depending upon desired output voltage. Figure 7. Trim Connections Using Fixed Resistors "T" Model, LSM-T/10-D12, Trimming This version of the LSM 10A series offers a special output voltage trimming feature which is fully compatible with competitive units. The output voltage may be varied from 0.75 to 5 Volts using a single external trim up resistor connected from the Trim input to Output Common. If no trim resistor is attached (Trim pin open), the output is 0.7525 Volts. The trim may also be adjusted using an external reference voltage connected to the Trim input. As with other trim adjustments, use a 1% metal film precision resistor with low temperature coefficient (100 ppm/C or less) mounted close to the converter with short leads. Also be aware that the output accuracy is 2% (typical) therefore you may need to vary this resistance slightly to achieve your desired output setting. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 7 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters The resistor trim up equation for the LSM-T/10-D12 is as follows: RTRIMUP () = 10500 -1000 VO - 0.7525 Where VO is the desired output voltage. The LSM-T/10-D12 fixed resistance values to set the output values are: VOUT (typ.) 0.7525 RTRIM (k) Open 1.0 1.2 41.424 22.46 1.5 1.8 2 2.5 3.3 5.0 13.05 9.024 7.417 5.009 3.122 1.472 CAUTION: To retain proper regulation, do not exceed the 5 Volt output. Voltage Trim The LSM-T/10-D12 may also be trimmed using an external voltage applied between the Trim input and Output Common. Be aware that the internal "load" impedance looking into trim pin is approximately 5k. Therefore, you may have to compensate for this in the source resistance of your external voltage reference. VTRIM = 0.7 -(0.0667 x (VO - 0.7525)) The LSM-T/10-D12 fixed trim voltages to set the output voltage are: VTRIM 0.7525 1.0 LSM-T/10-D12 thermal protection occurs at +125C and restart at approximately +115C. As you may deduce from the derating curves and observe in the efficiency curves on the following pages, LSM D12 SMT's maintain virtually constant efficiency from half to full load, and consequently deliver very impressive temperature performance even if operating at full load. Lastly, when LSM D12 SMT's are installed in system boards, they are obviously subject to numerous factors and tolerances not taken into account here. If you are attempting to extract the most current out of these units under demanding temperature conditions, we advise you to monitor the outputinductor temperature to ensure it remains below +110C at all times. Start Up Considerations When power is first applied to the DC/DC converter, operation is different than when the converter is running and stabilized. There is some risk of start up difficulties if you do not observe several application features. Lower input voltage converters may have more problems here since they tend to have higher input currents. Operation is most critical with any combination of the following external factors: The equation for this voltage adjustment is: VOUT (typ.) The highest temperatures in LSM D12 SMT's occur at their output inductor, whose heat is generated primarily by I 2 R losses. The derating curves were developed using thermocouples to monitor the inductor temperature and varying the load to keep that temperature below +110C under the assorted conditions of air flow and air temperature. Once the temperature exceeds +115C (approx.), the thermal protection will disable the converter. Automatic restart occurs after the temperature has dropped below +110C. 1.2 1.5 1.8 2 2.5 3.3 5.0 Open 0.68354 0.67 0.65 0.63 0.617 0.583 0.53 0.4166 1 - Low initial input line voltage and/or poor regulation of the input source. 2 - Full output load current on lower output voltage converters. 3 - Slow slew rate of input voltage. Output Reverse Conduction Many DC/DCs using synchronous rectification suffer from Output Reverse Conduction. If those devices have a voltage applied across their output before a voltage is applied to their input (this typically occurs when another power supply starts before them in a power-sequenced application), they will either fail to start or self destruct. In both cases, the cause is the "freewheeling" or "catch" FET biasing itself on and effectively becoming a short circuit. 4 - Longer distance to input voltage source and/or higher external input source impedance. LSM D12 SMT DC/DC converters do not suffer from Output Reverse Conduction. They employ proprietary gate drive circuitry that makes them immune to applied output voltages. 8 - Output loads with excessive inductive reactance or constant current characteristics. Thermal Considerations and Thermal Protection The typical output-current thermal-derating curves shown below enable designers to determine how much current they can reliably derive from each model of the LSM D12 SMT's under known ambient-temperature and air-flow conditions. Similarly, the curves indicate how much air flow is required to reliably deliver a specific output current at known temperatures. 5 - Limited or insufficient ground plane. External wiring that is too small. 6 - Too small external input capacitance. Too high ESR. 7 - High output capacitance causing a start up charge overcurrent surge. If the input voltage is already at the low limit before power is applied, the start up surge current may instantaneously reduce the voltage at the input terminals to below the specified minimum voltage. Even if this voltage depression is very brief, this may interfere with the on-board controller and possibly cause a failed start. Or the converter may start but the input current load will now drive the input voltage below its running low limit and the converter will shut down. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 8 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters If you measure the input voltage before start up with a Digital Voltmeter (DVM), the voltage may appear to be adequate. Limited external capacitance and/or too high a source impedance may cause a short downward spike at power up, causing an instantaneous voltage drop. Use an oscilloscope not a DVM to observe this spike. The converter's soft-start controller is sensitive to input voltage. What matters here is the actual voltage at the input terminals at all times. Increase the input start up voltage if possible to raise the downward voltage spike. Also, make sure that the input voltage ramps up in a reasonably short time (less than a few milliseconds). If possible, move the input source closer to the converter to reduce ohmic losses in the input wiring. Remember that the input current is carried both by the wiring and the ground plane return. Make sure the ground plane uses adequate thickness copper. Run additional bus wire if necessary. Symptoms of start-up difficulties may include failed started, output oscillation or brief start up then overcurrent shutdown. Since the input voltage is never absolutely constant, the converter may start up some times and not others. Any added output capacitor should use just enough capacitance (and no more) to reduce output noise at the load and to avoid marginal threshold noise problems with external logic. An output cap will also "decouple" inductive reactance in the load. Certain kinds of electronic loads include "constant current" characteristics which destabilize the output with insufficient capacitance. If the wiring to the eventual load is long, consider placing this decoupling cap at the load. Use the Remote Sense input to avoid ohmic voltage drop errors. Solutions To improve start up, review the conditions above. One of the better solutions is to place a moderate size capacitor very close to the input terminals. You may need two parallel capacitors. A larger electrolytic or tantalum cap supplies the surge current and a smaller parallel low-ESR ceramic cap gives low AC impedance. Too large an electrolytic capacitor may have higher internal impedance (ESR) and/or lower the start up slew rate enough to upset the DC/DC's controller. Make sure the capacitors can tolerate reflected switching current pulses from the converter. The capacitors will not help if the input source has poor regulation. A converter which starts successfully at 3.3 Volts will turn off if the input voltage decays to below the input voltage theshold, regardless of external capacitance. An elegant solution to start up problems is to apply the input voltage with the Remote On/Off control first in the off setting (for those converters with an On/Off Control). After the specified start-up delay (usually under 20 mSec), turn on the converter. The controller will have already been stabilized. The short delay will not be noticed in most applications. Be aware of applications which need "power management" (phased start up). Finally, it is challenging to model some application circuits with absolute fidelity. How low is the resistance of your ground plane? What is the inductance (and distributed capacitance) of external wiring? Even a detailed mathematical model may not get all aspects of your circuit. Therefore it is difficult to give cap values which serve all applications. Some experimentation may be required. Typical Performance Curves for LSM D12 SMT Series ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 9 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 10 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 11 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 12 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series ,3- $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 3-4 MOUNT AIR FLOW DIRECTION FROM PIN TO PIN # /UTPUT #URRENT !MPS %FFICIENCY 6). 6 .ATURAL #ONVECTION LFM LFM 6). 6 6). 6 n !MBIENT 4EMPERATURE o# ,OAD #URRENT !MPS ,3- 4 $ %FFICIENCY VS ,INE 6OLTAGE AND ,OAD #URRENT ,3- 4 $ -AXIMUM /UTPUT #URRENT VS !MBIENT 4EMPERATURE 6/54 6 TRANSVERSE AIRFLOW # 6/54 6 /UTPUT #URRENT !MPS %FFICIENCY 6). 6 6). 6 6). 6 .ATURAL #ONVECTION LFM LFM LFM LFM ,OAD #URRENT !MPS n !MBIENT 4EMPERATURE o# www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 13 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series Start-Up from ON/OFF (VIN = 12V, IOUT = 0.8V/10A, COUT = 22F) Start-Up from VIN (VIN = 12V, IOUT = 0.8V/10A, COUT = 22F) VIN 5V/div VIN 5V/div VOUT 1V/div VOUT 1V/div 10msec/div 10msec/div Start-Up from VIN (VIN = 12V, IOUT = 5V/10A, COUT = 22F) Start-Up from ON/OFF (VIN = 12V, IOUT = 5V/10A, COUT = 22F) VIN 5V/div VIN 5V/div VOUT 2V/div VOUT 2V/div 10msec/div 10msec/div www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 14 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series Output Hiccup (LSM-5/10-D12 Shorted VOUT, VIN = 12V) Input Reflected Ripple Current (Input Filter = 220F/12H/33F, VIN = 12V, IOUT = 5V/10A) 100mV/div 50mA/div 20msec/div 2sec/div Output Ripple and Noise (VIN = 12V, VOUT = 5V/10A, COUT= 22F) 20mV/div Output Ripple and Noise (VIN = 12V, VOUT = 0.8V/10A, COUT = 22F) 20mV/div 2sec/div 2sec/div www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 15 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Typical Performance Curves for LSM D12 SMT Series Dynamic Load Response (VIN = 12V, VOUT = 5V, 0 to 10A Step, COUT = 22F) 200mV/div Dynamic Load Response (VIN = 12V, VOUT = 5V, 0 to 10A Step, CO = 22F + 1000F Oscon) 100mV/div 100sec/div 100sec/div Dynamic Load Response (VIN = 12V, VOUT = 0.8V, 5 to 10A Step, COUT= 22F) 100mV/div Dynamic Load Response (VIN = 12V, VOUT = 5V, 5 to 10A Step, CO = 22F + 1000F Oscon) 100mV/div 100sec/div 100sec/div www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 16 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Tape & Reel Surface Mount Package Murata Power Solutions' LSM series DC/DC converters are the only highercurrent (10A) SMT DC/DC's that can be automatically "pick-and-placed" using standard vacuum-pickup equipment (nozzle size and style, vacuum pressure and placement speed may need to be optimized for automated pick and place) and subsequently reflowed using high-temperature, lead-free solder. Virtually all SMT DC/DCs today are unprotected "open-frame" devices assembled by their vendors with high-temperature solder (usually Sn96.5/Ag3.5 with a melting point +221C) so that you may attach them to your board using low-temperature solder (usually Sn63/Pb37 with a melting point of +183C). Conceptually straightforward, this "stepped" solder approach has its limitations, and it is clearly out of step with an industry trending toward the broad use of lead-free solders. Are you to experiment and develop reflow profiles from other vendors that ensure the components on those DC/DC never exceed 215-216C? If those components get too hot, "double-reflow" could compromise the reliability of their solder joints. Virtually all these devices demand you "cool down" the Sn63 profile you are likely using today. MPS is not exempted from the Laws of Physics. And we do not have magic solders no one else has. We do have a simple and practical, straightforward approach that works. We assemble our SMT DC/DC's on a thermally-stable plastic lead-frame (nylon 46, UL94V-0 flammability rated) using a high temperature lead-free solder. In addition, the LSM is transitioning to RoHS (Reduction of Hazardous Substances) construction and SAC 305 RoHS-approved solder. The lead-frame ensures coplanarity (to within 0.004 in.) of the unit's copper leads. These leads are gold-plated with a nickel underplate. See Mechanical Data for additional information. The disposable heat shield, with a cutaway exposing the package leads, provides thermal insulation to internal components during reflow and doubles as the vacuum pick-up location. The insulation properties of the heat shield are so effective that temperature differentials as high as 50C develop inside-tooutside the shield. Oven temperature profiles with peaks of 250-260C and dwell times exceeding 2 minutes above 221C are easily achieved. MPS's new-generation SMT units are shipped in stackable, JEDEC-style plastic tray. HEAT SHIELD OUTSIDE TEMPERATURE 250 Sn96.5/Ag3.5 Melting Point Temperature (C) 221 200 183 Sn63/Pb37 Melting Point 150 PCB TEMPERATURE INSIDE THE HEAT SHIELD 100 50 0 50 100 150 200 250 300 350 400 Time (Seconds) Figure 6. Reflow Solder Profile www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 17 of 18 LSM-10A D12 Models Single Output Non-Isolated, 12Vin, 0.75-5Vout DC/DC Converters Murata Power Solutions' new-generation LSM SMT DC/DC converters are shipped in quantities of 150 modules per tape and reel. 1.102 (28) 0.158 (4) 2.205 (56) 1.370 (34.8) CENTERED PICK UP LOCATION NOTCH IN SHELL INDICATES PIN ONE. 2.063 (52.4) 1 1 1 CAUTION PRESS TO REMOVE THE HEAT SHIELD AFTER THE SOLDER PROCESS. FEED DIRECTION TAPE DIMENSIONS IN INCHES (mm) 0.590 (14.97) 2.44 (62.0) 0.605 (15.36) Figure 7. Tape Dimensions 13.0 (330.2) 7.38 (187.5) 0.51(13.0) Figure 8. Reel Dimensions Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. ISO 9001 and 14001 REGISTERED This product is subject to the following operating requirements and the Life and Safety Critical Application Sales Policy: Refer to: http://www.murata-ps.com/requirements/ Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. (c) 2013 Murata Power Solutions, Inc. www.murata-ps.com/support MDC_LSM 10A D12 Models.D02 Page 18 of 18