7 Detailed Description

7.1 Overview

The TPSM861253 is a 1A, integrated FETs and inductor, synchronous buck module that operates from 3.8V

to 17V input voltage. TPSM861253 is a fixed 3.3V output voltage device The device employs a D-CAP3

control mode that provides fast transient response with no external compensation components and an accurate

feedback voltage. The proprietary D-CAP3 control mode enables low external component count, ease of design,

and optimization of the power design for cost, size, and efficiency.

The TPSM861253 is able to adapt to both low equivalent series resistance (ESR) output capacitors such as

POSCAP or SP-CAP, and ultra-low ESR ceramic capacitors.

7.2 Functional Block Diagram

SW

XCON

+

+

OT Protection

155°C /20°C

VIN

Internal

VCC

PGND

PWM

UV

+

SS

VREF

FB

Control Logic

On and off time

Minimum on and off time

Light load

OCP/OVP/UVP/NOC/TSD

Soft start

LDO

Internal Compensation

+

+

+

OV

2.9 V / 2.7 V

VREGOK

EN

UV threshold

OV threshold

EN Threshold

Internal SS

+

+

+

+

OCL

NOCL

ZC

+

Clock

VIN

PG

Internal

BST

AGND

VOUT

AGND

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TPSM861253

SLUSFD2A – SEPTEMBER 2023 – REVISED JANUARY 2024

Copyright © 2024 Texas Instruments Incorporated

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Product Folder Links: TPSM861253