8925
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
WITH LINEAR CURRENT CONTROL
AND POWER DMOS OUTPUTS
DISCONTINUED PRODUCT
— FOR REFERENCE ONL
Y
POWER
GROUND
6 5 4 3 2 1
44 43 42 41 40
7
8
9
10
11
12
13
14
15
16
17
29
30
39
38
37
36
35
34
33
32
31
2827262524232221201918
V
CC
POWER
GROUND
POWER
GROUND
POWER
GROUND
V
BB
CHARGE PUMPS
SEQUENCING AND CONTROL
CIRCUITRY
V
SENSE
BRAKE
COMP.
H
1
H
3
H
2
LOAD SUPPLY
NC NC
LOGIC GROUND NC
A
OUT
B
OUTOUT
C
ENABLE FAULTPOLE TACHNC LOGIC SUPPLY
ERROR AMP
SUB SUB
+
REFERENCE
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
WITH LINEAR CURRENT CONTROL
AND POWER DMOS OUTPUTS
The A8925CEB is a DMOS three-phase brushless dc motor con-
troller/driver designed for use in Winchester disk drives and other data
storage applications. The power output stages are capable of ±4 A
output currents and have DMOS power outputs with less than 0.25 Ω
r
DS(on)
for low power dissipation. Intrinsic ground clamp and flyback
diodes protect the output drivers when switching inductive loads.
Thermal shutdown circuitry is provided to protect the device from ex-
cessive junction temperature.
A transconductance amplifier is used to linearly regulate the load
current and control motor speed. Internal current-sensing circuitry
eliminates the need for external sense resistors. Analog and digital
control circuitry provide complete sequencing of the output drivers as
well as providing brake, disable, and tachometer functions. A FAULT
output flag indicates the presence of an under-voltage condition on the
12 V supply, excessive junction temperature, or an invalid Hall input
combination. The A8925CEB’s commutation logic is compatible with
motors that have digital Hall-effect sensors with 120° of electrical
separation. Internal charge pump circuitry is provided to drive the N-
channel DMOS source drivers to their required gate voltages.
The A8925CEB is provided in a 44-lead PLCC power package for
surface-mount applications. The copper batwing provides for maxi-
mum allowable package power dissipation in the smallest possible
construction.
FEATURES
a73 DMOS Outputs
a73 Low r
DS(on)
- 0.25 Ω Maximum
a73 Linear Current Control
a73 Internal Commutation Circuitry
a73 Internal Current Sensing
a73 Thermal Shutdown Circuitry
a73 Under Voltage Detection Circuitry
a73 Fault Output Flag
a73 Power Surface-Mount Package
Always order by complete part number: A8925CEB .
ABSOLUTE MAXIMUM RATINGS
AT T
A
= +25°C
Load Supply Voltage, V
BB
.....................14 V
Output Current, I
OUT
.......................... ±4.0 A
Logic Supply Voltage, V
CC
.....................14 V
Logic Input Voltage Range,
V
IN
................................ -0.3 V to +6.0 V
Package Power Dissipation,
P
D
......................................... See Graph
Operating Temperature Range,
T
A
..................................... 0°C to +70°C
Junction Temperature, T
J
............... +150°C†
Storage Temperature Range,
T
S
................................ -55°C to +150°C
† Fault conditions that produce excessive
junction temperature will activate device thermal
shutdown circuitry. These conditions can be
tolerated, but should be avoided.
Output current rating may be restricted to a value
determined by system concerns and factors.
These include: system duty cycle and timing,
ambient temperature, and use of any heatsinking
and/or forced cooling. For reliable operation, the
specified maximum junction temperature should
not be exceeded.
Dwg. PP-034
Data Sheet
26301.30
8925