Datasheet LTM4628 (Analog Devices) - 10

LTM4628
OPERATION Power Module Description
The LTM4628 is internally compensated to be stable over The LTM4628 is a dual-output standalone nonisolated all operating conditions. Table 2 provides a guideline switching mode DC/DC power supply. It can provide two for input and output capacitances for several operating 8A outputs with few external input and output capacitors conditions. LTpowerCAD™ is available for transient and and setup components. This module provides precisely stability analysis. The VFB pin is used to program the regulated output voltages programmable via external output voltage with a single external resistor to ground. resistors from 0.6V A differential remote sense amplifier is available for sens- DC to 5VDC over 4.5V to 26.5V input voltages. The typical application schematic is shown in ing the output voltage accurately on one of the outputs at Figure 28. the load point, or in parallel operation sensing the output voltage at the load point. The LTM4628 has dual integrated constant-frequency cur- rent mode regulators and built-in power MOSFET devices Multiphase operation can be easily employed with the with fast switching speed. The typical switching frequency MODE_PLLIN, PHASMD, and CLKOUT pins. Up to 12 is 550kHz. For switching-noise sensitive applications, it phases can be cascaded to run simultaneously with re- can be externally synchronized from 400kHz to 780kHz. spect to each other by programming the PHASMD pin to A resistor can be used to program a free run frequency different levels. See the Applications Information section. on the fSET pin. See the Applications Information section. High efficiency at light loads can be accomplished with With current mode control and internal feedback loop selectable Burst Mode operation or pulse-skipping compensation, the LTM4628 module has sufficient stabil- operation using the MODE_PLLIN pin. These light load ity margins and good transient performance with a wide features will accommodate battery operation. Efficiency range of output capacitors, even with all ceramic output graphs are provided for light load operation in the Typical capacitors. Performance Characteristics section. See the Applications Information section for details. Current mode control provides cycle-by-cycle fast current limit and foldback current limit in an overcurrent condition. A temperature diode is included inside the module to moni- Internal overvoltage and undervoltage comparators pull tor the temperature of the module. See the Applications the open-drain PGOOD outputs low if the output feedback Information section for details. voltage exits a ±7.5% window around the regulation point. The switch pins are available for functional operation If the output voltage exceeds 10% above its normal op- monitoring and a resistor-capacitor snubber circuit can erating point then the bottom power MOSFET will try to be carefully placed on the switch pin to ground to dampen clamp the output to protect it. any high frequency ringing on the transition edges. See Pulling the RUN pins below 1.1V forces the regulators into the Applications Information section for details. a shutdown state, by turning off both MOSFETs. The TRACK pins are used for programming the output voltage ramp and voltage tracking during start-up or used for soft-starting the regulator. See the Applications Information section. 4628fe 10 For more information www.linear.com/LTM4628 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Package Photos Revision History Typical Application Related Parts