LSM-1

LSM-10A D3 Models Single Output, Non-Isolated, 3.3VIN, 0.8-2.5VOUT 10 Amp DC/DC’s in SMT Packages Features Typical Unit Step-down buck regulators with industry-standard SMT footprint 3.3V input (3.0-3.6V range) 0.8/1/1.2/1.5/1.8/2/2.5VOUT @ 10A Non-isolated, fixed-frequency, synchronous-rectifier topology Tape and reel SMT package ±1% setpoint accuracy Efficiencies to 94% @ 10 Amps Noise as low as 30mVp-p Stable no-load operation Remote on/off control Sense pin and output voltage trim Thermal shutdown No derating to +70°C, natural convection UL/IEC/EN60950 certified EMC compliant DATEL's LSM D3 Series for SMT (surface-mount) are non-isolated DC/DC converters that accept a 3.3V input (3.0V to 3.6V input range) and deliver 1V, 1.2V, 1.5V, 1.8V, 2V or 2.5V outputs at 10 Amps. LSM D3 SMT's are designed to take onboard 3.3V power and convert it, with the highest efficiency in the smallest space, to any lower voltage required by today's current-hungry DSP's, ASIC's and CPLD's. The LSM D3's miniature size makes them ideal for true point-of-use/load power processing. They occupy a mere 0.7 square inches (4.5 cm2) and are only 0.34 inches (8.64 mm) high. The SMT package is designed for pick and place including lead free reflow soldering, and they typically require no additional external components. The LSM's best-in-class power density is achieved with a fully synchronous, fixed-frequency (300kHz), buck topology that also delivers: high efficiency (94% for 2.5VOUT models), low noise (30mVp-p typ.), tight line/load regulation (±0.1%/±0.25% max.), quick step response (100μsec), stable no-load operation, and no output reverse conduction. The fully functional LSM's feature output overcurrent detection, continuous shortcircuit and over-temperature protection, an output-voltage trim function, a remote on/ off control pin (pull low to disable), and a sense pin. High efficiency enables the LSM D3's to deliver rated output currents of 10 Amps at ambient temperatures to +70°C with no air flow (natural convection). If your low-voltage, high-current requirements have made the use of inefficient linear regulators impractical, take a look at one of DATEL's easy-to-use, low-cost LSM SMT's (or equivalent LSN SIP's). All devices are UL/IEC/EN60950 certified and EMC compliant. UL, CB, HALT and EMC reports are available upon request. +INPUT (2) +OUTPUT (4) +SENSE (6) COMMON (3) CURRENT SENSE VCC ON/OFF CONTROL (1) PWM CONTROLLER REFERENCE & ERROR AMP VOUT TRIM (5) COMMON (3) 　 Figure 1. Simplified Schematic For devices with the sense-pin removed ("B" suffix), the feedback path is through the +Output pin and not the +Sense pin. Typical topology is shown For full details go to www.murata-ps.com/rohs www.murata-ps.com Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000 MDC_LSM-10A D3.B01 Page 1 of 13 LSM-10A D3 Models Single Output, Non-Isolated, 3.3VIN, 0.8-2.5VOUT 10 Amp DC/DC’s in SMT Packages Performance Specifications and Ordering Guide Output Model LSM-0.8/10-D3 LSM-1/10-D3 LSM-1.2/10-D3 LSM-1.5/10-D3 LSM-1.8/10-D3 LSM-2/10-D3 LSM-2.5/10-D3 Input Regulation (Max.) Line Load ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% ±0.25% ±0.25% ±0.25% ±0.25% ±0.25% ±0.25% ±0.25% VOUT (Volts) 0.8 1 1.2 1.5 1.8 2 2.5 IOUT (Amps) 10 10 10 10 10 10 10 R/N (mVp-p) Typ. Max. 30 30 30 30 30 30 30 50 50 50 50 50 50 50 VIN Nom. (Volts) 3.3 3.3 3.3 3.3 3.3 3.3 3.3 Range (Volts) 3-3.6 3-3.6 3-3.6 3-3.6 3-3.6 3-3.6 3-3.6 IIN (mA/A) 70/3.0 70/3.52 70/4.13 70/5.05 70/5.96 70/6.55 70/8.1 Efficiency Full Load ½ Load Min. 81% 84% 86% 88% 89.5% 90.5% 91.5% Typ. 84% 86% 88% 90% 91.5% 92.5% 93.5% Typ. 85% 90% 91% 92% 93% 94% 95% Package (Case, Pinout) C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 C45, P63 Typical at TA = +25°C under nominal line voltage and full-load conditions, unless otherwise noted. All models are tested and specified with external 22μF 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. 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. Contact DATEL for availability. PART NUMBER STRUCTURE MECHANICAL SPECIFICATIONS Output Configuration: L = Unipolar Low Voltage L SM - 1.8 / 10 - D3 - C RoHS-6 compliant* Non-Isolated SMT Nominal Output Voltage: 0.8, 1, 1.2, 1.5, 1.8, 2, or 2.5 Volts Input Voltage Range: D3 = 3.0 to 3.6 Volts (3.3V nominal) Maximum Rated Output Current in Amps Note: Not all model number combinations are available. Contact Murata Power Solutions (DATEL). Case C45 1.36 (34.54) 0.55 (13.97) 0.310 (7.87) 0.570 (14.48) 3 EQ. SP. @ 0.190 (4.83) 0.010 (0.254) 0.60 (15.24) DIMENSIONS ARE IN INCHES (MM) 0.375 (9.53) 0.052 (1.32) 3 4 5 6 1 0.062 (1.57) 2 0.112 TYP. (2.84) 0.049 (1.24) 0.047 (1.19) BOTTOM VIEW 0.052 (1.32) LSM WITH REMOVEABLE HEAT SHIELD FOR HIGH TEMPERATURE SOLDER Refer to the last page for Tape and Reel information. CAUTION PRESS TO REMOVE THE HEAT SHIELD AFTER THE SOLDER PROCESS NOTCH IN SHELL INDICATES PIN ONE Pin 1 2 3 4 5 6 I/O Connections Function P63 On/Off Control +Input Common +Output VOUT Trim +Sense www.murata-ps.com Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000 MDC_LSM-10A D3.B01 Page 2 of 13 LSM-10A D3 Models Single Output, Non-Isolated, 3.3VIN, 0.8-2.5VOUT 10 Amp DC/DC’s in SMT Packages Performance/Functional Specifications Typical @ TA = +25°C under nominal line voltage and full-load conditions unless noted. Absolute Maximum Ratings Input Voltage: Continuous or transient On/Off Control (Pin 1) Input Reverse-Polarity Protection Output Overvoltage Protection Output Current short without damage. Storage Temperature Lead Temperature (soldering, 10 sec.) 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 4.5 to 5.5 Volts (5V nominal) See Ordering Guide 0.01A2sec 8mA 110mA average 10mAp-p Capacitive (44μF) None None None On = open (internal pull-up to +VIN) Off = 0 to +0.8V (1ma max.) 6 Volts +VIN None None Current limited. Devices can withstand sustained output circuits –40 to +125°C 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. Output VOUT Accuracy (50% load) Minimum Loading Maximum Capacitive Load VOUT Trim Range Ripple/Noise (20MHz BW) Total Accuracy Efficiency ±1% maximum No load 1000μF (low ESR, OSCON) ±10% (0.8V not trimmable) See Ordering Guide 3% over line/load temperature See Ordering Guide TECHNICAL NOTES I/O Filtering and Noise Reduction All models in the LSM D3 Series are tested and specified with external 22μF 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 D3'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 D3'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 22μF 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. Overcurrent Detection and Short-Circuit Protection: Current-Limiting Detection Point 17 (13-23.5) Amps Short-Circuit Detection Point 98% of VOUT set SC Protection Technique Hiccup with auto recovery Short-Circuit Current 600mA average Dynamic Characteristics Transient Response (50% load step) Start-Up Time: VIN to VOUT On/Off to VOUT Switching Frequency: Calculated MTBF 100μsec to ±2% of final value 7msec 6msec 300kHz (+40/–50kHz) Environmental 2.3-1.8 million hours (1VOUT to 5VOUT) Operating Temperature: (Ambient) Without Derating (Natural convection) –40 to +65/71°C (model dependent) With Derating See Derating Curves Thermal Shutdown Dimensions Pin Dimensions/Material Weight Flammability Rating Safety +115°C (110 to 125°C) Physical 1.3" x 0.53" x 0.34" (33.02 x 13.46 x 8.64 mm) 0.112" x 0.062" (2.84 x 1.57mm) rectangular copper with gold plate over nickel underplate 0.28 ounces (7.8g) UL94V-0 UL/cUL/IEC/EN 60950, CSA-C22.2 No. 60950 All models are tested and specified with external 22μF 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. 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 = +25°C, full power, natural convection, +67°C pcb temperature. Figure 2. Measuring Input Ripple Current www.murata-ps.com Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000 MDC_LSM-10A D3.B01 Page 3 of 13 LSM-10A D3 Models Single Output, Non-Isolated, 3.3VIN, 0.8-2.5VOUT 10 Amp DC/DC’s in SMT Packages 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. Input Overvoltage and Reverse-Polarity Protection LSM D3 SMT Series DC/DC's 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 (3 Volts) 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 D3 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 DC/DC 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 low-impedance 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. 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 +SENSE +OUTPUT 6 4 COPPER STRIP C1 C2 SCOPE RLOAD COMMON 3 COPPER STRIP C1 = NA C2 = 22μF 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 D3 Series DC/DC converters 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 17 Amps should be installed within the ungrounded input path to the converter. As a rule of thumb however, we recommend to use a normal-blow or slowblow fuse with a typical value of about twice the maximum input current, calculated at low line with the converters minimum efficiency. Safety Considerations LSM D3 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). 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. 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: (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. For the "B" model number option (sense pad removed), the sense is internally connected to +VOUT. Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000 www.murata-ps.com MDC_LSM-10A D3.B01 Page 4 of 13 LSM-10A D3 Models Single Output, Non-Isolated, 3.3VIN, 0.8-2.5VOUT 10 Amp DC/DC’s in SMT Packages On/Off Control The On/Off Control pin may be used for remote on/off operation. LSM D3 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 +0.8V relative to Common). As shown in Figure 4, all models have an internal 5k pull-up resistor to VIN (+Input). 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. +INPUT 5k 10k EXTERNAL OPEN COLLECTOR INPUT COMMON External Input Open: External Input Low: On/Off pin Low = DC/DC converter Off On/Off pin High = DC/DC converter On Figure 5. Driving the External Power-Up Open Collector 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 D3 SMT Series DC/DC converters incorporate an output overcurrent detection and shutdown function that serves to protect both the power converter and its load. ON/OFF pin open: ON/OFF pin