8936
VOICE COIL MOTOR DRIVER
TEST CIRCUIT AND TYPICAL APPLICATION
RZ
Rgm
CZ
VIN
VREF = 2 V
H GAIN
PWR OFF
FRAULT ≥ 200 kΩ
ERROR
– AMP
+
V CC
I SENSE +
+5 V
V DD
V REF
––
POWER
AMP
+
2V –
C1 R1
VOICE COIL
MOTOR
POWER
CONTROL
LOGIC
TSD
I SENSE –
CURRENT-SENSE
AMP
–
VREF +
RS
V SENS
PROTECTION
CIRCUITRY
RETRACT
CONTROL
QS
WINDOW
COMP.
V REF
QR
R
5
VCC
R7
R6
R8
BACK EMF FROM
SPINDLE MOTOR
VDD
DIODE FOR RETRACT FUNCTION
OTHERWISE SHORT TO SUPPLY
Dwg. EP-043A