L6243 [STMICROELECTRONICS]
VOICE COIL MOTOR DRIVER; 音圈电机驱动器
| 型号： | L6243 |
| 厂家： | 
ST |
| 描述： | VOICE COIL MOTOR DRIVER |
| 文件： | 总12页 (文件大小：115K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
L6243
L6243D
VOICE COIL MOTOR DRIVER
12V/5V OPERATION
PARKING FUNCTION FOR HARD DISK
HEAD ACTUATOR
OUTPUT CURRENT UP TO 2A DC, 2.5A
PEAK
LOW SATURATION VOLTAGE
LOGIC AND POWER SUPPLY MONITOR
LINEAR CONTROL
THERMAL PROTECTION
ENABLE FUNCTION
PLCC44
ORDERING NUMBERS:
L6243
SO(24+2+2)
L6243D
CURRENT SENSE RESISTOR CONNEC-
TIONS
as a Transconductance Amplifier to drive a
Voice Coil Motor in LinearMode.
Additional features include Power On Reset De-
lay, Enable and Park, as well as a general pur-
pose Operational Amplifier. A logic low at the
Park input activates the parking function. Holding
the Enable input low will disable the device by
forcing the outputs into a tristate mode. Power
Fail Monitors for the logic and power supplies in-
itiate an automatic parking sequence during a
power failure. A resistor programmed parking
voltage enables a constant velocity head retract.
DESCRIPTION
The L6243/D is a Bipolar IC developed for use in
Hard Disk Head Actuator positioning applications.
The Power Op-Amp Output Bridge, Differential
Amplifier, and Error Amplifier, are controlled by
TTL/CMOS, input compatible, Digital Logic, and
an Analog Current Control Voltage. A simple
RC compensation network, tied to the output of
the Error Amp, will configure the system to work
BLOCK DIAGRAM
July 1996
1/12
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
L6243-L6243D
PIN CONNECTION
PLCC-44
(Top view)
6
5
4
3
2
1 44 43 42 41 40
GND
7
39
38
37
36
35
34
33
32
31
30
29
GND
ERROR AMP INPUT
ERROR AMP OUTPUT
OP AMP -INPUT
8
SENSE AMP INPUT A
9
N.C.
10
11
12
13
14
15
16
17
GND
OP AMP +INPUT
N.C.
OP AMP OUTPUT
GND
GND
N.C.
WRITE DISABLE OUTPUT
POWER ON RESET OUTPUT
PARK VOLTAGE PROGRAM
GND
N.C.
GND
ENABLE INPUT
GND
18 19 20 21 22 23 24 25 26 27 28
D96IN449
V
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
SENSE AMP OUTPUT
SO 24+2+2
REF
N.C.
N.C.
N.C.
2
V
CC
3
PARK POWER
OUTPUT B
4
ERROR AMP INPUT
ERROR OUTPUT
5
SENSE AMP INPUT B
SENSE AMP INPUT A
GND
6
GND
7
GND
8
GND
WRITE DISABLE OUTPUT
POWER ON RESET OUTPUT
PARK VOLTAGE PROGRAM
POWER FAIL THRESHOLD
9
ENABLE
10
11
12
13
14
PARK INPUT
OUTPUT A
5V FILTER
V
CC
SENSE OUTPUT
V
CC
POWER ON RESET DELAY
LOGIC SUPPLY SENSE (5V)
D96IN450
2/12
L6243-L6243D
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
VS
VIN
VID
IO
Supply Voltage
18
0.3V to VS
±VS
V
Input Voltage
Differential Input Voltage
DC Output Current
2
A
A
Ip
Peak Output Current (non repetitive)
2.5
Ptot
Total Power Dissipation (Tamb = 70 C) for L6243
2
1.2
W
W
°
for L6243D
Tstg
Storage and Junction Temperature
-55 to +150
°C
THERMAL DATA
Symbol
Description
L6243
L6243D
Unit
Rth j-pin
Rth j-amb
Rth j-amb
Thermal Resistance Junction to pin
12
62
36
14
°C/W
°C/W
C/W
°
Thermal Resistance Junction to pin floating in air
Thermal Resistance Junction to pin 16 cm2 copper area on board
heat sink
50
PIN FUNCTIONS
Name
VCC
Function
Power supply.
GND
Common Ground.
Vref
Voltage Reference.
Input. Logic low will disable IC.
ENABLE
PARK POWER
CURRENT SENSE OUT
ERROR AMP IN
ERROR AMP OUT
Input Power supply for the parking circuit.
Current sense operational amplifier output.
Error amplifier inverting input.
Error amplifier output.
SENSE IN
OUT A, B
PARK
Input for external sense resistors.
±
Outputs of the two Power Operational Amplifiers Connections for Voice coil Motor.
External input for parking. Low will activate the park procedure.
Input to set the park voltage.
PARK VOLTAGE PROGRAM
POWER FAIL THRESHOLD
LOGIC SUPPLY SENSE
5V FILTER
Supply monitor threshold setting.
Logic Supply Sense.
Capacitor connection to filter the logic supply ripple.
Power supply failure monitor output.
VCC SENSE OUT
POR
Power on reset output. Low will signal to the controller the failure of the logic supply.
Capacitor connection to set the power on reset delay.
Output for write disable. Low will disable the writing mode.
Inverting input of the additional op amp.
POR DELAY
WRITE DISABLE
AMP–
AMP+
Non-inverting input of the additional op amp.
Output of the additional op amp.
AMPOUT
3/12
L6243-L6243D
ELECTRICAL CHARACTERISTICS (VS = 12V, Tamb = 25°C; unless otherwise specified)
Symbol
Parameter
Supply Range
Test Condition
Min.
Typ.
Max.
Unit
V
VS
Id
4.5
13.2
Quiescent Drain Current
20
mA
°C
Tj
Thermal Shutdown Junction
Temperature
160
ERROR AMPLIFIER
Ib
Input Bias Current
1
300
5
A
µ
IOS
VOS
Gv
Input Offset Current
Input Offset Voltage
nA
mV
dB
Large Signal Open Loop Voltage
Gain
65
5
GBW
Gmin
IO+
Gain Bandwidth
3
MHz
Minimum Voltage Gain
Output Source Current
Output Sink Current
Slew-rate
6
6
2
mA
mA
IO–-
SR
V/ s
µ
SENSE AMPLIFIER
RIN, Vref
Ad
Vref Input Impedance
9
K
Ω
Differential Gain
8
1
3
V/V
V/µs
MHz
KΩ
SR
Slew-rate
GBW
Rin
Gain Bandwidth Product
Sense Input Impedance
Common Mode Rejection Ratio
1.5
55
CMRR
dB
POWER OP. AMP.
GV
Vd
Voltage Gain
26
dB
Total Output Voltage Drop
IO = 250mA
IO = 500mA
IO = 1A
450
750
1.15
mV
mV
V
1.5
2.5
IO = 2A
2.30
V
Voff
BW
Offset Voltage on Sense
Resistor
5
mV
Bandwidth on Resistive Load
100
KHz
GENERAL PURPOSE OP-AMP
Ib
Input Bias Current
Input Offset Current
Input Offset Voltage
1
300
5
µA
nA
mV
dB
IOS
VOS
GV
Large Signal Open Loop Voltage
Gain
65
GBW
IO+
Gain Bandwidth Product
Output Source Current
Output Sink Current
Slew Rate
1
6
6
1
MHz
mA
IO–
mA
SR
V/ s
µ
4/12
L6243-L6243D
ELECTRICAL CHARACTERISTICS (continued)
MONITORS AND CONTROL CIRCUIT
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
Vt1
Threshold Voltage at Logic
Supply Sense
4.45
4.60
4.75
V
Vt2
Threshold Voltage at Power Fail
Threshold Input
1.375
1.4
1.435
V
HVt1
HVt2
Vll
Hysteresis on Vt1
Hysteresis on Vt2
Low Level Voltage
50
15
mV
mV
mV
mV
µA
Write Disable = 2mA
Power on Reset = 2mA
Vi = 2.4V
250
250
500
500
Ie
Ip
Enable Input Current
Input Current at Park
100
Vi = 0.4V
–200
100
µA
Vi = 2.4V
µA
Vi = 0.4V
–200
A
µ
Rf
Equivalent Input Resistance at
5V Filter Input
6.9
KΩ
Venl
Venh
Vph
Vpl
Enable Low Input Voltage
0.8
V
V
Enable High Input Voltage
Parking Input High Voltage
Parking Input Low Voltage
Power Fail Low Output Voltage
Parking Voltage Program Current
2
2
V
0.8
0.5
V
Vpfl
Iprog
Ich
Il = 2mA
V
100
10
µA
µA
Power On Reset Delay
Capacitor Charging
Td
Delay Between Write Disable
and Power on Reset Falling
Edges
4
10
µs
FUNCTIONAL DESCRIPTION
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
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 true”, or ”non asserted” condition. From in-
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.
5/12
L6243-L6243D
FUNCTIONAL DESCRIPTION
(continued)
Function
Description
VCC input
This is the Power Supply input.
POWER FAIL
THRESH
Input for the VCC supply monitor. The Threshold can be externally set via a voltage divider.
V
CC SENSE OUT
Output
TTL compatible signal indicating the VCC supply has dropped below the POWER FAIL
THRESHOLD.
LOGIC SUPPLY
SENSE input
This input is used to monitor the Five Volt Logic Supply for the external control and other support
IC’s. The LOGIC SUPPLY SENSE operates independently of the 12V Power Supply. When a
5V supply failure is detected a POWER ON RESET is generated.
5V FILTER input
This pin allows for the application of filter circuitry in order to avoid false triggering.
PARK POWER
input
This input is used during the Power Down/Power Fail Parking operation. When the supply goes
down, a typical Spindle Driver Circuit automatically tristates its output stages. During this time
the spindle motor spins freely and the stored energy is used to drive the VCM to the park
position. The generated BEMF is rectified and filtered across an external PARKING
CAPACITOR.
PROGRAMMABLE Used to set the voltage applied to the VCM during an Automatic Parking Operation.
PARK VOLTAGE
input
PARK
input
Logic signal asserted low, activates parking.
POWER ON
RESET output
Indicates an error condition to the external control and support circuitry. A Logic Supply Fail
condition automatically initiates a POWER ON RESET. Internal 30k Pullup to LSS.
POWER ON
RESET DELAY
input
The intent of this input is to provide a time delay at power up. During this time, the POWER ON
RESET line will be asserted (low). A POWER ON RESET, will hold the system in the PARK
mode. Once the delay has timed out, the POWER ON RESET will be removed to allow the
external system to assume control. When applied in a Disk Drive Application, the POWER ON
RESET DELAY will be required to have a minimum duration which will ensure that the
Read/Write Heads can be fully parked.
WRITE DISABLE
output
Becomes asserted a few microseconds prior to the assertion of POWER ON RESET.
Internal 30k Pullup to LSS.
ENABLE input
This signal originates at the external controller and, when asserted, allows the VCM Drivers to
operate. When deasserted the VCM Driver is forced into Tristate mode. During a POWER ON
RESET condition however, the parking operation is automatic and takes priority over the
ENABLE function. Only at the end of the POWER ON RESET DELAY will the ENABLE input
become active. If active parking is desired, it will be accomplished under control of the VIN
signal, otherwise it is an automatic function at power down.
VREF input
The reference voltage input is basically that voltage, at which the output current is zero.
ERROR AMP IN
input
Inverting input of error amplifier. The non inverting one is internally tied to V .
ref
Open collector output.
ERROR AMP OUT Error amplifier output pin.
output
OUTPUT A power Voice Coil power output.
output
OUTPUT B power Voice Coil power output.
output
SENSE AMP IN
A/B signal input
Sense amplifier input pins. The sense resistor is connected across these pins.
SENSE AMP OUT Output pin of sense amplifier.
signal output
AMPOUT output Output of an internal op-amp for general application.
AMP+ input
AMP- input
General purpose op-amp non inverting input.
General purpose op-amp inverting input.
6/12
L6243-L6243D
Write Disable and Power on Reset are delayed
(typ 4µs) in order to disable the writing on the disk
before the Power on Reset is activated. An addi-
tional supervisor circuit is present in the IC with a
programmable threshold, which is set by an exter-
nal resistive divider. The TTL compatible output
can be used separately or connected to Park in-
put in order to park the head.
BLOCK DESCRIPTION
OUTPUT STAGE
It consists of two Power Op Amps connected in
bridge configuration.
CURRENT SENSE AMPLIFIER
Differential amplifier whose inputs are connected
to the sense lines and whose output is accessible
externally. Closing the loop will transform the
differential voltage signal from the sense lines into
a current signal for the Error Amplifier.
The VCC sense output pin can also be connected
to 5V filter input in order to implement a POWER
ON RESET function sensitive both to 5V and VCC
.
PARKING CIRCUIT OPERATIONT
The voice coil driver is switched into the parking
condition when Power on Reset output or Park in-
put are low. In such a condition a fixed voltage is
superimposed on the load and the value of such a
voltage is set by connecting an external resistor
between Park Voltage Program input and
ERROR AMPLIFIER
Error amplifier which drives the output stage. The
input and the output pins are accessible exter-
nally.
µ
ground: (Vpark=Rext x Iref, Iref=100 A typ). Con-
POWER SUPPLY MONITOR OPERATION
necting ENABLE input to GND the driver will be
disabled (outputs in high impedance mode).
The circuit monitors the logic supply voltage input
(typ 5V) and activates Power on Reset and Write
Disable output when such a supply drops below
the safe operating limit. After the logic supply volt-
age reaches its nominal value a delay capacitor
has to be charged [Tdelay=3x10e5 x C sec] be-
fore Power on Reset and Write Disable outputs
change from low to high level. Falling edges of
THERMAL SHUTDOWN
It will disable the IC when the junction tempera-
ture exceeds the threshold value above which the
device could be damaged.
Figure 1: ApplicationCircuit (The pinout refers to the L6243)
7/12
L6243-L6243D
Figure 2: Waveforms
8/12
L6243-L6243D
THERMAL CHARACTERISTICS
Figure 3: Rth (j-amb) vs. Dissipated Power
Figure 4:
Rth (j-amb) vs. Dissipated Power
9/12
L6243-L6243D
PLCC44 PACKAGE MECHANICAL DATA
mm
inch
TYP.
DIM.
MIN.
17.4
16.51
3.65
4.2
TYP.
MAX.
17.65
16.65
3.7
MIN.
0.685
0.650
0.144
0.165
0.102
MAX.
0.695
0.656
0.146
0.180
0.108
A
B
C
D
4.57
2.74
d1
d2
E
2.59
0.68
0.027
14.99
16
0.590
0.630
e
1.27
12.7
0.46
0.71
0.050
0.500
0.018
0.028
e3
F
F1
G
0.101
0.004
M
M1
1.16
1.14
0.046
0.045
10/12
L6243-L6243D
SO28 PACKAGE MECHANICAL DATA
mm
inch
TYP.
DIM.
MIN.
TYP.
MAX.
2.65
0.3
MIN.
MAX.
0.104
0.012
0.019
0.013
A
a1
b
0.1
0.004
0.014
0.009
0.35
0.23
0.49
0.32
b1
C
c1
D
E
0.5
0.020
45° (typ.)
17.7
10
18.1
0.697
0.394
0.713
0.419
10.65
e
1.27
0.050
0.65
e3
F
16.51
7.4
0.4
7.6
0.291
0.016
0.299
0.050
L
1.27
S
8° (max.)
11/12
L6243-L6243D
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specification mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as criticalcomponents in life support devices or systems without express
written approval of SGS-THOMSON Microelectronics.
1996 SGS-THOMSON Microelectronics – Printedin Italy – All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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12/12
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