TPS2834, TPS2835

SYNCHRONOUS-BUCK MOSFET DRIVERS

WITH DEADTIME CONTROL

SLVS223 – NOVEMBER 1999

2

POST OFFICE BOX 655303

functional block diagram

DT

6

IN

VCC

LOWDR

BOOTLO

HIGHDR

BOOT

PGND

2

8

14

12

11

10

VCC

7

ENABLE

1

SYNC

5

CROWBAR

3

(TPS2834 Only)

(TPS2835 Only)

200 k

Ω

200 k

Ω

200 k

Ω

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 to develop the floating

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

µF and 1 µF.

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

Deadtime 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 TPS2834; inverting input for the TPS2835).

LOWDR

10

O

Output drive for the low-side power MOSFET

NC

4, 9, 13

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.