BOOT

SW

ILIM

EN/SS

COMP

FB

GND

VDD

BP

PGOOD

PAD

VIN

+

+

FB

0.6 V

0.6 V

+

Fault

Controller

SS

Soft Start

BP

Anti-Cross

Conduction

and

Pre-Bias

Circuit

PWM

Logic

BP

Clock

6-V

Regulator

References

0.6

V

REF

SD

BP

Oscillator

+

Calibration

Circuit

+

UDG-11046

0.6 V

REF

SS

10 mA

750 kW

Fault Controller

Thermal

Shutdown

OC

Threshold

Setting

10 mA

OC

SS

SD

PWM

Clock

OC

TPS56221

10

TPS56221

SLUSAH5D – MARCH 2011 – REVISED FEBRUARY 2016

www.ti.com

Product Folder Links: TPS56221

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Copyright © 2011–2016, Texas Instruments Incorporated

7 Detailed Description

7.1 Overview

The TPS56221 is a 25-A high-performance synchronous buck converter with two integrated N-channel NexFET

power MOSFETs. The device implements a voltage-mode control with voltage feed-forward compensation that

responds instantly to input voltage change. Prebias capability eliminates concerns about damaging sensitive

loads.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Voltage Reference

The 600-mV bandgap cell is internally connected to the noninverting input of the error amplifier. The reference

voltage is trimmed with the error amplifier in a unity gain configuration to remove amplifier offset from the final

regulation voltage. The 1% tolerance on the reference voltage allows the user to design a very accurate power

supply.