5

6

7

8

9

10

GHC

26

27

28

29

19

24

25

SENSE

22

23

21

Dwg. PP-068

11

12

13

CC

GLB

SB

GHB

CB

GLA

SA

GHA

RC

PWM

BRKSEL

BRKCAP

BRAKE

DIR

H2

H3

The A3933SEQ is a three-phase MOSFET controller for use with

bipolar brushless dc motors. It drives all n-channel external power

FETs, allowing system cost savings and minimizing

The high-side drive block is implemented with bootstrap capacitors at

each output to provide the floating positive supply for the gate drive.

The high-side circuitry also employs a unique “intelligent” FET

monitoring circuit that ensures the gate voltages are at the proper levels

before turn-on and during the ON cycle. This device is targeted for

applications with motor supplies from 12 V to 28 V.

Internal fixed off-time PWM current-control circuitry can be used to

regulate the maximum load current to a desired value. The peak load-

current limit is set by the user’s selection of an input reference voltage

and external sensing resistor. The fixed off-time pulse duration is set

by a user-selected external RC timing network.

A power-loss braking circuit brakes the motor on an under-voltage

condition. The device is configured to either coast or dynamically

brake the motor when this occurs.

The A3933SEQ is supplied in a 32-lead rectangular (9 x 7) plastic

chip carrier (quad pack) for minimum-area, surface-mount applica-

tions.

3933

I Drives External N-Channel FETs

I Intelligent High-Side Gate Drive

I Selectable Coast or Dynamic Brake on Power Down

I Adjustable Dead Time for Cross-Conduction Protection

I Selectable Fast or Slow Current-Decay Modes

I Internal PWM Peak Current Control

I Reset/Coast Input

I 120° Hall Commutation with Internal Pullup

I Internal 5-V Regulator

I Low-Side Synchronous Rectification

I Direction Control

I PWM Speed-Control Input

I Fault-Diagnostic Output

I Under-Voltage Protection

THREE-PHASE POWER

MOSFET CONTROLLER

ABSOLUTE MAXIMUM RATINGS

(peak) .............................................. 30 V

(peak) .............................................. 15 V

Logic Input Voltage Range,

Sense Voltage Range,

Output Voltage Range,

Operating Temperature Range,

Storage Temperature Range,