MOTOR DRIVER. 8958 Datasheet

8958 DRIVER. Datasheet pdf. Equivalent

Part 8958
Description VOICE COIL MOTOR DRIVER
Feature 8958 LOGIC SUPPLY INHIBIT UV1 UV2 LIMIT GROUND AB GROUND AB PARK VOLTAGE SENSE IN– IN A+ IN A– OUT A.
Manufacture Allegro MicroSystems
Datasheet
Download 8958 Datasheet

8958 LOGIC SUPPLY INHIBIT UV1 UV2 LIMIT GROUND AB GROUND AB 8958 Datasheet
Recommendation Recommendation Datasheet 8958 Datasheet





8958
8958
LOGIC
SUPPLY
1
VCC
INHIBIT
UV1
2
1.5 V +
3
UV2 4
LIMIT 5
GROUNDAB 6
GROUNDAB
PARK
VOLTAGE
SENSE IN–
7
8
99
IN A+ 10
IN A–
OUT A
11
12
+
A
-
24 SENSE OUT
23 PARK
DRIVE
22 PARK
21 GROUND
20 PWR OK
19 GROUNDAB
18 GROUNDAB
17 SENSEIN+
+ 16
B
- 15
VBB 14
13
IN B+
IN B–
LOAD
SUPPLY
OUT B
Dwg. PP-054
ABSOLUTE MAXIMUM RATINGS
at TA = 25°C
Supply Voltages, VBB and VCC ............... 16 V
Output Current, IOUT ............................ ±1.0 A
Park Drive Output Current, IPARK
Continuous ................................ 250 mA
Peak .............................................. 1.0 A
Amplifier Input Voltage Range,
VIN ..................................... -2.0 V to VCC
Sense Input Voltage Range,
VSENSE IN ............................ -0.3 V to VCC
Comparator and Digital Inputs,
VIN .................................... -0.3 V to 10 V
IIN .............................................. ±10 mA
Power OK Output, VCEX ......................... 20 V
IC ................................................. 30 mA
Output Clamp Diode Current,
IF (pulsed) ..................................... 1.0 A
Package Power Dissipation, PD .. See Graph
Operating Temperature Range,
TA ...................................... 0°C to +70°C
Junction Temperature, TJ ................... 150°C*
Storage Temperature Range,
TS ................................ -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.
VOICE COIL MOTOR DRIVER
Providing control and drive of the voice coil motor used for head
positioning in disk drive applications, the A8958CLB is a full-bridge
driver which can be configured so that its output current is a direct
function of an externally applied control voltage or current. This linear
current control function is supplemented by additional circuitry to
protect the heads and the data disk during system failure or normal
system shutdown.
The two ±800 mA driver outputs provide very-low saturation voltage
drops and precise current control utilizing a single current-sensing
resistor connected in series with the load. Under-voltage lockout
disables the system in a controlled sequence if a fault condition occurs.
When activated by the under-voltage comparator, or a park com-
mand, the output power drivers change from a controlled current to a
user-determined constant park voltage. Other features include a power
ok flag, a limit input to force the outputs to their maximum level in either
polarity, an over-riding output disable to shut down both power amplifi-
ers and reduce quiescent supply current, and internal thermal shutdown
which disables the load (but still allowing the head to be parked) in the
event of excessive junction temperatures. The load is re-enabled when
the junction temperature returns to a safe level.
The A8958CLB is supplied in a 24-lead power SOIC for surface-
mount applications. The copper batwing construction provides for
maximum package power dissipation in a minimum package size. It is
rated for continuous operation over the temperature range of 0°C to
+70°C.
FEATURES
s Controlled-Velocity Head Parking
s Zero Deadband
s High Transconductance Bandwidth
s User-Adjustable Transconductance Gain
s ±800 mA Load Current
s Dual Under-Voltage Monitors
with Flag and User-Selectable Trip Points
s Internal Thermal Shutdown Circuitry
s Replaces UC3175
Always order by complete part number, e.g., A8958CLB .



8958
8958
VOICE COIL
MOTOR DRIVER
PARK
VOLTAGE
8
LIMIT 5
+
1.5 V
IN A– 11
IN A+ 10
GROUNDAB 6, 7
SENSE IN+ 17
SENSE IN– 9
4 k
4 k
PARK 22
PWR OK 20
(ACTIVE HIGH)
FUNCTIONAL BLOCK DIAGRAM
14 LOAD
SUPPLY
2 INHIBIT
A
1.5 V
+
12
OUT A
8 k
+
8 k
24
SENSE OUT
VBB
13
OUT B
TSD
B
+
15 INB–
16 IN B+
18, 19 GROUNDAB
23 PARK
DRIVE
1.5 V
BANDGAP REF
V CC
+
3V
1
LOGIC
SUPPLY
21 GROUND
+
+ 1.5 V
4 UV1
3 UV2
Dwg. FP-020C
5
RθJT = 6.0°C/W
4
3
2
1 RθJA = 55°C/W
0
25
50 75 100
TEMPERATURE IN °C
125 150
Dwg. GP-033A
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1990, 2000 Allegro MicroSystems, Inc.





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