COMP

3

FB

4

TPS40200

SS

2

ISNS

7

Soft-Start

and

E/A and SS

Reference

+

Enable E/A

+

700 mV

8

Logic

Driver

6

RC

1

OSC

UVLO

5 GND

PWM

VDD

GDRV

DD

8V) typical

GDRV voltage swing

limited to (V

±

Overcurrent

TPS40200-Q1

SLUS739F – SEPTEMBER 2006 – REVISED JANUARY 2016

www.ti.com

7 Detailed Description

7.1 Overview

The TPS40200-Q1 is a nonsynchronous controller with a built-in 200-mA driver designed to drive high-speed

P-channel FETs up to 500 kHz. Its small size combined with complete functionality makes the device both

versatile and easy to use.

The controller uses a low-value current-sensing resistor in series with the input voltage and the source

connection of the power FET to detect switching current. When the voltage drop across this resistor exceeds

100 mV, the device enters a hiccup fault mode at approximately 2% of the operating frequency.

The device uses voltage feedback to an error amplifier that is biased by a precision 700-mV reference. Feed-

forward compensation from the input keeps the PWM gain constant over the full input voltage range, eliminating

the need to change frequency compensation for different input voltages.

The device also incorporates a soft-start feature, where the output follows a slowly rising soft-start voltage,

preventing output-voltage overshoot.

7.2 Functional Block Diagram

NOTE

In this block diagram and the following sections, the internal R resistor values and

capacitor mV reference values are typical. Resistor and reference voltage values will vary

based on process, temperature, and supply voltage of the device. Please see Electrical

Characteristics for tolerances, where applicable.

10

Submit Documentation Feedback

Copyright © 2006–2016, Texas Instruments Incorporated

Product Folder Links: TPS40200-Q1