LTM4638 BLOCK DIAGRAM PGOOD 10k INTVCC INTVCC V 2.2µF IN VIN 3.1V TO 20V 0.1µF CIN MODE/CLKIN 22µF 25V 20k 0.24µH VOUT VOUT CLKOUT 1.5V COUT 15A 100µF POWER CONTROL 1µF PHMODE ×3 GND 6.3V TRACK/SS V – OSNS 0.1µF – DIFF RFB RUN AMP 40.2k V FB IN + COMPa 60.4k V + OSNS COMPb INTERNAL INTERNAL FILTER COMP 274k FREQ GND 4638 BD Figure 1. Simplified LTM4638 Block DiagramDECOUPLING REQUIREMENTS SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS CIN External Input Capacitor Requirement IOUT = 15A 22 44 µF (VIN = 3.1V to 20V, VOUT = 1.5V) COUT External Output Capacitor Requirement IOUT = 15A 220* 470* µF (VIN = 3.1V to 20V, VOUT = 1.5V) *Additional capacitance may be required under extreme temperature and/or capacitor bias voltage conditions due to variation of actual capacitance over bias voltage and temperature. Rev. B For more information www.analog.com 9 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Decoupling Requirements Operation Applications Information Package Description Revision History Package Photo Related Parts