1 LTM4637 . 20A DC/DC Module Step-Down Regulator Features Description n Complete 20A Switch Mode Power Supply The LTM 4637 is a complete 20A output high efficiency n to 20V Input Voltage Range switch mode Step-Down DC/DC Module (micromodule). n to Output Voltage Range Regulator . Included in the package are the switching control- n Total DC Output Voltage Error ler, power FETs, inductor and compensation components. ( 40 C to 125 C) Operating over an input voltage range from to 20V, n Differential Remote Sense Amplifier for Precision the LTM4637 supports an output voltage range of Regulation for (VOUT ) to , set by a single external resistor.
2 Only a few input n Current Mode Control/Fast Transient Response and output capacitors are needed. n Parallel Current Sharing (Up to 80A). n Frequency Synchronization Current mode operation allows precision current sharing n Selectable Pulse-Skipping or Burst Mode Operation of up to four LTM4637 regulators to obtain up to 80A. n Soft-Start/Voltage Tracking output. High switching frequency and a current mode n Up to 88% Efficiency (12V , IN OUT). architecture enable a very fast transient response to line n Overcurrent Foldback Protection and load changes without sacrificing stability.
3 The device n Output Overvoltage Protection supports frequency synchronization, multiphase/current n Internal Temperature Monitor sharing, Burst Mode operation and output voltage tracking n Overtemperature Protection for supply rail sequencing. A diode-connected PNP transis- n 15mm 15mm LGA and tor is available for use as an internal temperature monitor. 15mm 15mm BGA Packages The LTM4637 is offered in 15mm 15mm LGA. n SnPb (BGA) or RoHS Compliant (LGA and BGA) Finish and 15mm 15mm packages. The LTM4637 . is available with SnPb (BGA) or RoHS compliant terminal Applications finish.
4 The LTM4637 is pin compatible with the LTM4627, n Telecom Servers and Networking Equipment a 15A DC/DC Module Regulator . n Industrial Equipment L, LT, LTC, LTM, PolyPhase, Burst Mode, Module, Linear Technology, the Linear logo are registered trademarks and LTpowerCAD is a trademark of Linear Technology Corporation. n Medical Systems All other trademarks are the property of their respective owners. Protected by Patents, n High Ambient Temperature Systems including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611, 6677210, 8163643. Typical Application 12 VIN, , 20A DC/DC Module Regulator 12 VIN Efficiency vs Load Current F 100.
5 VIN. 250kHz 12V 22 F 95. CCM. 16V 10k VIN EXTVCC INTVCC PGOOD. 4 VOUT 90. F COMP VOUT EFFICIENCY (%). 20A. TRACK/SS VOUT_LCL 85. 330pF 100 F* + 470 F. RUN DIFF_OUT LTM4637 80. 2 2. fSET VOSNS+. 75. MODE_PLLIN VOSNS . TEMP VFB 70. SGND GND RFB**. 65. * SEE TABLE 5 4637 TA01a 0 2 4 6 8 10 12 14 16 18 20. ** SEE TABLE 1. OUTPUT CURRENT (A) 4637 TA01b 4637fc For more information 1. LTM4637 . Absolute Maximum Ratings (Note 1). to 22V to to 6V INTVCC Peak Output Current (Note 6)..100mA. INTVCC, VOUT_LCL, PGOOD, to 6V Internal Operating Temperature Range MODE_PLLIN, fSET, TRACK/SS, (Note 2).
6 40 C to 125 C. VOSNS , VOSNS+, to INTVCC Storage Temperature 55 C to 125 C. VFB, COMP (Note 7) .. to Reflow (Peak Body) 245 C. RUN (Note 5).. to 5V. Pin Configuration TOP VIEW TOP VIEW. MODE_PLLIN MODE_PLLIN. VIN INTVCC TRACK/SS COMP VIN INTVCC TRACK/SS COMP. 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12. A A. RUN RUN. VIN B fSET VIN B fSET. C C. INTVCC INTVCC. D D. TEMP TEMP. E EXTVCC E EXTVCC. PGOOD PGOOD. F VFB F VFB. GND GND. G PGOOD G PGOOD. H SGND H SGND. J VOSNS+ J VOSNS+. K DIFF_OUT K DIFF_OUT. VOUT VOUT. L VOUT_LCL L VOUT_LCL.
7 M VOSNS M VOSNS . LGA PACKAGE BGA PACKAGE. 133-LEAD (15mm 15mm ) 133-LEAD (15mm 15mm ). TJ(MAX) = 125 C, JA = C/W, JCbottom = 4 C/W, JCtop = C/W, JB = C/W TJ(MAX) = 125 C, JA = C/W, JCbottom = C/W, JCtop = C/W, JB = C/W. JA DERIVED FROM 95mm 76mm PCB WITH 4 LAYERS; WEIGHT = JA DERIVED FROM 95mm 76mm PCB WITH 4 LAYERS; WEIGHT = VALUES DETERMINED PER JESD51-12 VALUES DETERMINED PER JESD51-12. Order Information PART NUMBER PAD OR BALL FINISH PART MARKING* PACKAGE MSL TEMPERATURE RANGE. DEVICE FINISH CODE TYPE RATING (Note 2). LTM4637EV#PBF Au (RoHS) LTM4637V e4 LGA 4 40 C to 125 C.
8 LTM4637IV#PBF Au (RoHS) LTM4637V e4 LGA 4 40 C to 125 C. LTM4637EY#PBF SAC305 (RoHS) LTM4637Y e1 BGA 4 40 C to 125 C. LTM4637IY#PBF SAC305 (RoHS) LTM4637Y e1 BGA 4 40 C to 125 C. LTM4637IY SnPb (63/37) LTM4637Y e0 BGA 4 40 C to 125 C. Consult Marketing for parts specified with wider operating temperature Recommended LGA and BGA PCB Assembly and Manufacturing ranges. *Device temperature grade is indicated by a label on the shipping Procedures: container. Pad or ball finish code is per IPC/JEDEC J-STD-609. Terminal Finish Part Marking: LGA and BGA Package and Tray Drawings: 4637fc 2 For more information LTM4637 .
9 Electrical Characteristics The l denotes the specifications which apply over the specified internal operating temperature range (Note 2), otherwise specifications are at TA = 25 C. VIN = 12V, per the typical application in Figure 22. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS. VIN Input DC Voltage l 20 V. VOUT Range VOUT Range l V. VOUT(DC) Output Voltage, Total CIN = 22 F 3 l V. Variation with Line and Load COUT = 100 F Ceramic, 470 F POSCAP. RFB = , MODE_PLLIN = GND. VIN = 5V to 20V, IOUT = 0A to 20A (Note 4). Input Specifications VRUN RUN Pin On Threshold VRUN Rising V.
10 VRUNHYS RUN Pin On Hysteresis 130 mV. IQ(VIN) Input Supply Bias Current VIN = 12V, VOUT = , Burst Mode Operation, IOUT = 17 mA. VIN = 12V, VOUT = , Pulse-Skipping Mode, IOUT = 25 mA. VIN = 12V, VOUT = , Switching Continuous, IOUT = 54 mA. Shutdown, RUN = 0, VIN = 12V 40 A. IS(VIN) Input Supply Current VIN = 5V, VOUT = , IOUT = 20A A. VIN = 12V, VOUT = , IOUT = 20A A. Output Specifications IOUT(DC) Output Continuous Current VIN = 12V, VOUT = (Note 4) 0 20 A. Range VOUT (Line) Line Regulation Accuracy VOUT = , VIN from to 20V l %/V. VOUT IOUT = 0A.