EN_UVLO

VOSNS

AGND

+

PWM

FSEL

ILIM

UV

OV

Delay

Control

PGOOD

REFIN_TRK

RSN

RSP

MODE

VSEL

MUX

+

+

External

soft-start

Internal

soft-start

+

+

+

SW

XCON

PVIN

BOOT

PGND

One-Shot

DRGND

VDD

LDO

Regulator

Control

Logic

BP

+

+

D-CAP3

TM

Ramp Generator

Switching

Frequency

Programmer

Reference

Generator

ZC

OCP

+

+

x

(1/16)

x

(±1/16)

MODE Logic

Copyright © 2016, Texas Instruments Incorporated

11

TPS548D21

www.ti.com

SLUSCI8 – JULY 2016

Product Folder Links: TPS548D21

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Copyright © 2016, Texas Instruments Incorporated

7 Detailed Description

7.1 Overview

TPS548D21 device is a high-efficiency, single channel, FET-integrated, synchronous buck converter. It is

suitable for point-of-load applications with 40 A or lower output current in storage, telecomm and similar digital

applications. The device features proprietary D-CAP3 mode control combined with adaptive on-time architecture.

This combination is ideal for building modern high/low duty ratio, ultra-fast load step response DC-DC converters.

TPS548D21 device has integrated MOSFETs rated at 40-A TDC.

The converter input voltage range is from 1.5 V up to 16 V, and the VDD input voltage range is from 4.5 V to

22 V. The output voltage ranges from 0.6 V to 5.5 V.

Stable operation with all ceramic output capacitors is supported, since the D-CAP3 mode uses emulated current

information to control the modulation. An advantage of this control scheme is that it does not require phase

compensation network outside which makes it easy to use and also enables low external component count. from

4 preset values via resistor settings by FSEL pin. Adaptive on-time control tracks the preset switching frequency

over a wide range of input and output voltage while increasing switching frequency as needed during load step

transient.

7.2 Functional Block Diagram