Datasheet LTM4604A (Analog Devices) - 9

LTM4604A
operaTion Power Module Description
PGOOD output low if the output feedback voltage exits a The LTM4604A is a standalone non-isolated switch mode ±7.5% window around the regulation point. Furthermore, DC/DC power supply. It can deliver up to 4A of DC output in an overvoltage condition, internal top FET M1 is turned current with few external input and output capacitors. off and bottom FET M2 is turned on and held on until the This module provides a precise regulated output voltage overvoltage condition clears. programmable via one external resistor from 0.8V DC to Pulling the RUN/SS pin below 0.5V forces the controller 5.0V DC over a 2.375V to 5.5V input voltage. A typical into its shutdown state, turning off both M1 and M2. At application schematic is shown in Figure 15. low load current, the module works in continuous current The LTM4604A has an integrated constant frequency mode by default to achieve minimum output voltage ripple. current mode regulator with built-in power MOSFETs with The TRACK pin is used for power supply tracking. See the fast switching speed. The typical switching frequency is Applications Information section. 1.25MHz. With current mode control and internal feedback The LTM4604A is internally compensated to be stable over loop compensation, the LTM4604A module has sufficient a wide operating range. Table 4 provides a guideline for stability margins and good transient performance under a input and output capacitance for several operating con- wide range of operating conditions and with a wide range ditions. The LTpowerCAD™ GUI is available for transient of output capacitors, even all ceramic output capacitors. and stability analysis. Current mode control provides cycle-by-cycle fast current The FB pin is used to program the output voltage with a limit. In addition, foldback current limiting is provided in single external resistor connected to ground. an overcurrent condition while VOUT drops. Internal over- voltage and undervoltage comparators pull the open-drain 4604afc For more information www.linear.com/LTM4604A 9 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Revision History Package Photograph Related Parts