L6243 STMicroelectronics, L6243 Datasheet - Page 5

• Manufacturer Part Number: L6243
• Description: MOSFET & Power Driver ICs DISC BY STM 2/01 PLCC44 VOICE COIL DR
• Manufacturer: STMicroelectronics

Specifications of L6243

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

ELECTRICAL CHARACTERISTICS (continued)
MONITORS AND CONTROL CIRCUIT
FUNCTIONAL DESCRIPTION
The VCM Driver is controlled via three control sig-
nals, ENABLE, POWER ON RESET, and WRITE
DISABLE. An analog input voltage, ERROR AMP
IN, controls the polarity and amplitude of the VCM
driving current.
Refer to figure two. This diagram is a repre-
sentation of the function of the VCM System.
Note that the signals with the bars represent the
”not
itial power up, the system is held in the Park
Mode. Upon completion of the POWER UP RE-
SET DELAY the machine moves to Tristate Mode
or Run Mode, depending upon the condition of
the ENABLE input. If ENABLE is asserted, the
machine moves directly to Run Mode. If ENABLE
is not asserted, the machine moves to Tristate
Mode.
Symbol
HV
HV
V
I
V
V
V
V
V
V
prog
I
V
R
T
I
I
enh
ch
enl
e
p
ph
pfl
t1
t2
pl
d
ll
f
t1
t2
true”, or ”non asserted” condition. From in -
Threshold Voltage at Logic
Supply Sense
Threshold Voltage at Power Fail
Threshold Input
Hysteresis on V
Hysteresis on Vt2
Low Level Voltage
Enable Input Current
Input Current at Park
Equivalent Input Resistance at
5V Filter Input
Enable Low Input Voltage
Enable High Input Voltage
Parking Input High Voltage
Parking Input Low Voltage
Power Fail Low Output Voltage
Parking Voltage Program Current
Power On Reset Delay
Capacitor Charging
Delay Between Write Disable
and Power on Reset Falling
Edges
Parameter
t1
Write Disable = 2mA
Power on Reset = 2mA
V
V
V
V
I
l
i
i
i
i
= 2mA
= 2.4V
= 0.4V
= 2.4V
= 0.4V
Test Condition
POWER ON RESET is an asynchronous output.
Additionally it affects the internal logic as a hard
wired reset and therefore if a supply failure occurs
during Tristate or Run state, the machine moves
directly back to the Park Mode. A WRITE DIS-
ABLE occurs a few to ten microseconds prior to
the POWER ON RESET in order for the system
to halt any read/write activity before a head re-
tract begins.
While in Tristate Mode, the assertion of ENABLE
will move the machine to the Run Mode. Run
Mode will typically be the steady running state.
The deassertion of the ENABLE signal causes
the machine to move into Tristate. If it is desired
to perform an active Parking function, the PARK
input must be driven low by the external hard-
ware, or the the VCM can be driven to the Park
position via the ERROR AMP IN control voltage
1.375
Min.
4.45
2
2
Typ.
4.60
250
250
100
1.4
6.9
50
15
10
4
L6243-L6243D
1.435
Max.
–200
–200
4.75
500
500
100
100
0.8
0.8
0.5
10
Unit
mV
mV
mV
mV
K
V
V
V
V
V
V
V
A
A
A
A
A
A
s
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