8925 Datasheet, PDF (1/8 Pages) Allegro MicroSystems – 3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER WITH LINEAR CURRENT CONTROL AND POWER DMOS OUTPUTS

8925
8925 ^{3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER}
WITH LINEAR CURRENT CONTROL
AND POWER DMOS OUTPUTS
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
POWER ₇
39 ^POWER
output currents and have DMOS power outputs with less than 0.25 Ω
GROUND
GROUND
8
9
10
11
T ₁₂
C ₁₃
14
U ₁₅
D ^Y 16
L _{POWER 17}
+
GROUND
SUB
38
37
36
35
34
33
32
31
30
29 ^POWER
GROUND
SUB
PRO ^ON _Dwg.PP-034
ED ^{CE ABSOLUTE MAXIMUM RATINGS}
U ^{N AT TA = +25°C}
Load Supply Voltage, V_BB ..................... 14 V
IN ^{E Output Current, IOUT .......................... ±4.0 A}
R _{Logic Supply Voltage, VCC .....................14 V}
Logic Input Voltage Range,
T _{E VIN ................................ -0.3 V to +6.0 V}
N ^F Package Power Dissipation,
P_D ......................................... See Graph
O E Operating Temperature Range,
T_A ..................................... 0°C to +70°C
C ^R _{Junction Temperature, TJ ............... +150°Câ€} 
Storage Temperature Range,
IS ^R T_S ................................ -55°C to +150°C
D ^O † Fault conditions that produce excessive
junction temperature will activate device thermal
F _{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.}
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
s DMOS Outputs
s Low r_DS(on) - 0.25 Ω Maximum
s Linear Current Control
s Internal Commutation Circuitry
s Internal Current Sensing
s Thermal Shutdown Circuitry
s Under Voltage Detection Circuitry
s Fault Output Flag
s Power Surface-Mount Package
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.
Always order by complete part number: A8925CEB .