TPS2830, TPS2831

FAST SYNCHRONOUSBUCK MOSFET DRIVERS

WITH DEADTIME CONTROL

SLVS196C − JANUARY1999 − REVISED JANUARY 2001

3

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

I/O

DESCRIPTION

NAME

NO.

I/O

DESCRIPTION

BOOT

14

I

Bootstrap terminal. A ceramic capacitor is connected between BOOT and BOOTLO terminals to develop the

floating bootstrap voltage for the high-side MOSFET. The capacitor value is typically between 0.1

µF and 1 µF.

A 1-M

Ω resistor should be connected across the bootstrap capacitor to provide a discharge path when the driver

has been powered down.

BOOTLO

11

O

This terminal connects to the junction of the high-side and low-side MOSFETs.

CROWBAR

3

I

CROWBAR can to be driven by an external OVP circuit to protect against a short across the high-side MOSFET.

If CROWBAR is driven low, the low-side driver will be turned on and the high-side driver will be turned off,

independent of the status of all other control terminals.

DT

6

I

Dead-time control terminal. Connect DT to the junction of the high-side and low-side MOSFETs.

ENABLE

1

I

If ENABLE is low, both drivers are off.

HIGHDR

12

O

Output drive for the high-side power MOSFET

IN

2

I

Input signal to the MOSFET drivers (noninverting input for the TPS2830; inverting input for the TPS2831).

LOWDR

10

O

Output drive for the low-side power MOSFET

NC

4, 9, 13

No internal connection

PGND

7

Power ground. Connect to the FET power ground

SYNC

5

I

Synchronous Rectifier Enable terminal. If SYNC is low, the low-side driver is always off; If SYNC is high, the

low-side driver provides gate drive to the low-side MOSFET.

VCC

8

I

Input supply. Recommended that a 1-

µF capacitor be connected from VCC to PGND.

detailed description

low-side driver

The low-side driver is designed to drive low Rds(on) N-channel MOSFETs. The current rating of the driver is

2 A, source and sink.

high-side driver

The high-side driver is designed to drive low Rds(on) N-channel MOSFETs. The current rating of the driver is

2 A, source and sink. The high-side driver can be configured as a GND-reference driver or as a floating bootstrap

driver. The internal bootstrap diode is a Schottky, for improved drive efficiency. The maximum voltage that can

be applied from BOOT to ground is 30 V.

Dead-time control prevents shoot through current from flowing through the main power FETs during switching

transitions by controlling the turn-on times of the MOSFET drivers. The high-side driver is not allowed to turn

on until the gate drive voltage to the low-side FET is low, and the low-side driver is not allowed to turn on until

the voltage at the junction of the power FETs (Vdrain) is low; the DT terminal connects to the junction of the power

FETs.

The ENABLE terminal enables the drivers. When enable is low, the output drivers are low.

The IN terminal is the input control signal for the drivers. The TPS2830 has a noninverting input; the TPS2831

has an inverting input.

†High-level input voltages on ENABLE, SYNC, CROWBAR, IN, and DT must be greater than or equal to 0.7VCC.