LTM4618 operaTion Power Module Description The LTM4618 is a standalone non-isolated switching mode Current mode control provides cycle-by-cycle fast current DC/DC power supply. It can deliver up to 6A (DC current) limit and current foldback in a short-circuit condition. Pull- output with few external input and output capacitors. This ing the RUN pin below 1.1V forces the controller into its module provides precisely regulated output voltages pro- shutdown state, by turning off both MOSFETs. The TK/SS grammable via external resistors from 0.8VDC to 5.0VDC pin can be used for programming the output voltage ramp over 4.5V to 26.5V input voltages. The typical application and voltage tracking during start-up. See the Applications schematic is shown in Figure 21. For VIN ≤ 6V, connect Information section. VIN, INTVCC and EXTVCC together. The LTM4618 is internally compensated to be stable over The LTM4618 has an integrated constant frequency current all operating conditions. LTpowerCAD™ is provided for mode regulator and built-in power MOSFET devices with transient and stability analysis. The VFB pin is used to fast switching speed. The typical switching frequency is program the output voltage with a single external resistor 780kHz. to ground. Multiphase operation can be easily employed With current mode control and internal feedback loop with the synchronization control. compensation, the LTM4618 module has sufficient stabil- High efficiency at light loads can be accomplished with ity margins and good transient performance with a wide selectable Burst Mode or pulse-skipping mode operations range of output capacitors, even with all ceramic output using the MODE/PLLIN pin. Efficiency graphs are provided capacitors. for light load operation in the Typical Performance Char- acteristics section. 4618fb For more information www.linear.com/LTM4618 9 Document Outline Features Description Applications 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 Photograph Package Description Revision History Typical Application Related Parts