1

11

PGND

SW

TPS53317

OC

ZC

XCON

16 BST

20 V5IN

PWM

10

19 PGOOD

Control Logic

UDG-11106

+

+

+

+

VOUT

+

One-

Shot

UV

OV

+

8 R

8

COMP

R

6

GND

7

VREF

On-Time

Selection

15 2A

18 MODE

+

+

Discharge

UVP

OVP

Current

Sense

+

VS

Amplifier

Current Sense

Amplifier

SW

PGND

4

5

VIN

VIN

12 SW

13 SW

14 SW

15 SW

2

PGND

3

PGND

17

EN

Delay

N

On/Off Time

N

Minimum On/Off

N

SKIP/FPWM

N

OCL/OVP/UVP

N

Discharge

+

9

REFIN

SS

DAC

Ramp

Comp

Internal Voltage

Reference

ZC Threshold

Modulation

PGND

GND

GND

DRVH

DRVL

Pad

TPS53317

www.ti.com

SLUSAK4D – JUNE 2011 – REVISED JULY 2015

7 Detailed Description

7.1 Overview

The TPS53317 device is a D-CAP+™ mode adaptive on-time converter. Integrated high-side and low-side FETs

support a maximum of 6-A DC output current. The converter automatically operates in discontinuous conduction

mode (DCM) to optimize light-load efficiency. Multiple switching frequencies are provided to enable optimization

of the power train for the cost, size and efficiency requirements of the design (see Table 1).

In adaptive on-time converters, the controller varies the on-time as a function of input and output voltage to

maintain a nearly constant frequency during steady-state conditions. In conventional constant on-time converters,

each cycle begins when the output voltage crosses to a fixed reference level. However, in the TPS53317 device,

the cycle begins when the current feedback reaches an error voltage level which is the amplified difference

between the reference voltage and the feedback voltage.

7.2 Functional Block Diagram

Copyright © 2011–2015, Texas Instruments Incorporated

Submit Documentation Feedback

11

Product Folder Links: TPS53317