ISL62875 Datasheet, PDF (7/22 Pages) Intersil Corporation – PWM DC/DC Controller with VID Inputs for Portable GPU Core-Voltage Regulator

ISL62875
Table of Contents
Application Schematics ....................................................................................................................... 2
Block Diagram .................................................................................................................................... 4
Pin Configuration ................................................................................................................................ 5
ISL62875 Functional Pin Descriptions ................................................................................................ 5
Ordering Information ......................................................................................................................... 6
Absolute Maximum Ratings ................................................................................................................ 8
Thermal Information .......................................................................................................................... 8
Recommended Operating Conditions .................................................................................................. 8
Electrical Specifications ...................................................................................................................... 8
Theory of Operation .......................................................................................................................... 11
Modulator ...................................................................................................................................... 11
Synchronous Rectification ................................................................................................................. 11
Diode Emulation .............................................................................................................................. 11
Power-On Reset .............................................................................................................................. 12
V_IN and PVCC Voltage Sequence ....................................................................................................... 12
Start-Up Timing .............................................................................................................................. 12
PGOOD Monitor ............................................................................................................................... 12
LGATE and UGATE MOSFET Gate-Drivers ............................................................................................ 12
Adaptive Shoot-Through Protection .................................................................................................... 12
Setpoint Reference Voltage Programming ........................................................................................ 13
Calculating Setpoint Voltage Programming Resistor Values ................................................................... 13
External Setpoint Reference .............................................................................................................. 14
Soft-Start and Voltage-Step Delay .................................................................................................... 14
Circuit Description ........................................................................................................................... 14
Component Selection For C_SOFT Capacitor .......................................................................................... 15
Compensation Design ....................................................................................................................... 15
Fault Protection ................................................................................................................................ 15
Overcurrent .................................................................................................................................... 15
Component Selection for R_OCSET and C_SEN ......................................................................................... 16
Overvoltage .................................................................................................................................... 16
Undervoltage .................................................................................................................................. 16
Over-Temperature ........................................................................................................................... 16
General Application Design Guide ..................................................................................................... 16
Selecting the LC Output Filter ........................................................................................................... 17
Selection of the Input Capacitor ........................................................................................................ 17
Selecting The Bootstrap Capacitor ..................................................................................................... 17
Driver Power Dissipation .................................................................................................................. 18
MOSFET Selection and Considerations ................................................................................................ 18
PCB Layout Considerations ............................................................................................................... 19
Power and Signal Layers Placement on the PCB ................................................................................... 19
Component Placement ..................................................................................................................... 19
Signal Ground and Power Ground ...................................................................................................... 19
Routing and Connection Details ......................................................................................................... 19
Copper Size for the Phase Node ........................................................................................................ 20
Revision History ............................................................................................................................... 21
Products ........................................................................................................................................... 21
Package Outline Drawing ................................................................................................................. 22
7
September 18, 2009
FN6905.1