Datasheet LTM4630 (Analog Devices) - 10

LTM4630
OPERATION Power Module Description
The LTM4630 is a dual-output standalone nonisolated used for soft-starting the regulator. See the Applications switching mode DC/DC power supply. It can provide two Information section. 18A outputs with few external input and output capacitors The LTM4630 is internally compensated to be stable over all and setup components. This module provides precisely operating conditions. Table 4 provides a guide line for input regulated output voltages programmable via external and output capacitances for several operating conditions. resistors from 0.6VDC to 1.8VDC over 4.5V to 15V input The Linear Technology µModule Power Design Tool will be voltages. The typical application schematic is shown in provided for transient and stability analysis. The V Figure 23. FB pin is used to program the output voltage with a single external The LTM4630 has dual integrated constant-frequency cur- resistor to ground. A differential remote sense amplifier is rent mode regulators and built-in power MOSFET devices available for sensing the output voltage accurately on one with fast switching speed. The typical switching frequency of the outputs at the load point, or in parallel operation is 500kHz. For switching-noise sensitive applications, it sensing the output voltage at the load point. can be externally synchronized from 400kHz to 780kHz. A Multiphase operation can be easily employed with the resistor can be used to program a free run frequency on MODE_PLLIN, PHASMD, and CLKOUT pins. Up to 12 the FSET pin. See the Applications Information section. phases can be cascaded to run simultaneously with re- With current mode control and internal feedback loop spect to each other by programming the PHASMD pin to compensation, the LTM4630 module has sufficient stabil- different levels. See the Applications Information section. ity margins and good transient performance with a wide High efficiency at light loads can be accomplished with range of output capacitors, even with all ceramic output selectable Burst Mode operation or pulse-skipping opera- capacitors. tion using the MODE_PLLIN pin. These light load features Current mode control provides cycle-by-cycle fast current will accommodate battery operation. Efficiency graphs are limit and foldback current limit in an overcurrent condition. provided for light load operation in the Typical Performance Internal overvoltage and undervoltage comparators pull Characteristics section. See the Applications Information the open-drain PGOOD outputs low if the output feedback section for details. voltage exits a ±10% window around the regulation point. A general purpose temperature diode is included inside As the output voltage exceeds 10% above regulation, the the module to monitor the temperature of the module. See bottom MOSFET will turn on to clamp the output voltage. the Applications Information section for details. The top MOSFET will be turned off. This overvoltage protect is feedback voltage referred. The switch pins are available for functional operation monitoring and a resistor-capacitor snubber circuit can Pulling the RUN pins below 1.1V forces the regulators be careful placed on the switch pin to ground to dampen into a shutdown state, by turning off both MOSFETs. any high frequency ringing on the transition edges. See The TRACK pins are used for programming the output the Applications Information section for details. voltage ramp and voltage tracking during start-up or 4630fa 10 For more information www.linear.com/LTM4630 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Operation Applications Information Package Description Related Parts