Datasheet LTM4630A (Analog Devices) - 10

LTM4630A
OPERATION Power Module Description
The LTM4630A is a dual-output standalone nonisolated voltage tracking during start-up or used for soft-starting switching mode DC/DC power supply. It can provide two the regulator. See the Applications Information section. 18A outputs with few external input and output capacitors The LTM4630A is internally compensated to be stable and setup components. This module provides precisely over all operating conditions. Table 6 provides a guide line regulated output voltages programmable via external for input and output capacitances for several operating resistors from 0.6VDC to 8VDC over 4.5V to 18V input conditions. The Linear Technology µModule Power Design voltages. The typical application schematic is shown in Tool will be transient and stability analysis. The V Figure 34. See Table 1 for different output current and FB pin is used to program the output voltage with a single external frequency guideline. resistor to ground. A differential remote sense amplifier is The LTM4630A has dual integrated constant-frequency available for sensing the output voltage accurately on one current mode regulators and built-in power MOSFET of the outputs at the load point, or in parallel operation devices with fast switching speed. For switching-noise sensing the output voltage at the load point. sensitive applications, it can be externally synchronized Multiphase operation can be easily employed with the from 300kHz to 780kHz. A resistor can be used to program MODE_PLLIN, PHASMD, and CLKOUT pins. Up to 12 a free run frequency on the FSET pin. See the Applications phases can be cascaded to run simultaneously with re- Information section. spect to each other by programming the PHASMD pin to With current mode control and internal feedback loop different levels. See the Applications Information section. compensation, the LTM4630A module has sufficient High efficiency at light loads can be accomplished with stability margins and good transient performance with selectable Burst Mode operation or pulse-skipping opera- a wide range of output capacitors, even with all ceramic tion using the MODE_PLLIN pin. These light load features output capacitors. will accommodate battery operation. Efficiency graphs are Current mode control provides cycle-by-cycle fast current provided for light load operation in the Typical Performance limit and foldback current limit in an overcurrent condition. Characteristics section. See the Applications Information Internal overvoltage and undervoltage comparators pull section for details. the open-drain PGOOD outputs low if the output feedback A general purpose temperature diode is included inside voltage exits a ±10% window around the regulation point. the module to monitor the temperature of the module. See As the output voltage exceeds 10% above regulation, the the Applications Information section for details. bottom MOSFET will turn on to clamp the output voltage. The top MOSFET will be turned off. This overvoltage protect The switch pins are available for functional operation is feedback voltage referred. monitoring and a resistor-capacitor snubber circuit can be careful placed on the switch pin to ground to dampen Pulling the RUN pins below 1.1V forces the regulators into any high frequency ringing on the transition edges. See a shutdown state, by turning off both MOSFETs. The TRACK the Applications Information section for details. pins are used for programming the output voltage ramp and 4630afb 10 For more information www.linear.com/LTM4630A Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Operation Applications Information Related Parts