Datasheet
SLVS367A − MARCH 2001 − REVISED JUNE 2001
4
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Terminal Functions
TERMINAL
NAME
NO.
DESCRIPTION
NAME
TPS283x TPS284x
DESCRIPTION
ADJ 6 — Adjust. The adjust pin is the feedback pin for the drive regulator (TPS283X only)
AGND 8 7 Analog ground
BOOT 16 14 Bootstrap. A capacitor is connected between the BOOT and BOOTLO pins to develop the floating
bootstrap voltage for the high-side MOSFET. The capacitor value is typically between 0.1 µF and 1 µF.
BOOTLO 14 12 Boot low. This pin connects to the junction of the high-side and low-side MOSFETs.
DELAY 4 4 Delay. Connecting a capacitor between this pin and ground adjusts the deadtime for high-side driver
DT 7 6 Deadtime control. Connect DT to the junction of the high-side and low-side MOSFETs
ENABLE 1 1 Enable. If ENABLE is low, both drivers are off.
HIGHDR 15 13 High drive. This pin is the output drive for the high-side power MOSFET.
IN 2 2 Input. This pin is the input signal to the MOSFET drivers.
LOWDR 11 9 Low drive. This pin is the output drive for the low-side power MOSFET.
NC 10 5 No internal connection
PGND 9 8 Power ground. This pin is connected to the FET power ground.
PWRRDY 3 3 Power ready. This open-drain pin indicates a power good for VDRV and V
CC
.
SYNC 5 — Synchronous rectifier enable. 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.
V
CC
13 11 Input power supply. It is recommended that a capacitor (minimum 1 µF) be connected from V
CC
to
PGND. Note that V
CC
must be 2 V higher than VDRV.
VDRV 12 10 Drive regulator output voltage. It is recommended that a capacitor (minimum 1 µF) be connected from
VDRV to PGND. Note that V
CC
must be 2 V higher than VDRV.
detailed description
low-side driver
The low-side driver is designed to drive low r
DS(on)
N-channel MOSFETs. The current rating of the driver is 4 A,
source and sink.
high-side driver
The high-side driver is designed to drive low r
DS(on)
N-channel MOSFETs. The current rating of the driver is 4 A
minimum, 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 (DT) control
Dead-time control prevents shoot-through current from flowing through the main power FETs during switching
transitions by controlling the turnon 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 (BOOTLO) is low. The TTL-compatible DT terminal connects to
the junction of the power FETs.
ENABLE
The ENABLE terminal enables the drivers. When enable is low, the output drivers are low. ENABLE is a
TTL-compatible digital terminal.