SGS Thomson Microelectronics L6243DS Datasheet

5-12V OPERATION
PARKING FUNCTION FOR HARD DISK

HEAD ACTUATOR
OUTPUT CURRENT UP TO 1A DC, 1.2A

PEAK
LOW SATURATION VOLTA GE
LOGIC AND POWER SUPPLY MONITOR
LINEAR CONTROL
THERMAL PROTECTION
ENABLE FUNCTION
CURRENT SENSE RESISTOR CONNEC-

TIONS

DESCRIPTION

The L6243DS is a Bipolar IC developed for use in
Mass Storage 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 net work, tied to the
output of the Error Amp, will configure the system

L6243DS

VOICE COIL MOTOR DRIVER

SO24

ORDERING NUMBER:

to work as a Transconductance Amplifier to drive
a Voice Coil Motor in Linear Mode.

Additional features include Power On Reset De­lay, Enable and Park. 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 initiate an auto­matic parking sequence during a power failure. A
resistor programmed parking voltage enables a
constant velocity head retract.

L6243DS

BLOCK DIAGRAM

PARK POWER

PARK VOLTAGE

February 1998

GND
VDD A
VDD B

PROGRAM

POWER FAIL
THRESHOLD

(12V)

LOGIC

SUPPLY

SENSE

SNUBBER

VOICE COIL

OUT A OUT B SENSE IN B SENSE IN A SENSE OUT ERROR IN ERROR OUT

BRIDGE
POWER

STAGE

PARK

VOLTAGE

GENERATOR

­+

+

-

INTERNAL
VOLTAGE

REFERENCE

Rsense

V

CC

POR DELAYLOGIC SUPPLY FILTER

­+

­+

PORVCC SENSE OUT

V

IN

Cf

R1

R2

Rf

­+

THERMAL

PROTECTION

FALL TIME

DELAY

VREF

PARK

ENABLE

D96IN469

1/8

L6243DS

PIN CONNECTION

(Top view)

LOGIC SUPPLY SENSE

VDDA
OUTA
PARK

ENABLE

GND
GND

SENSE IN A

LOGIC SUPPLY FILTER ERROR IN

SENSE IN B VREF

OUT B SENSE OUT11 14

2
3
4
5
6
7
8
9
10

D96IN467

24
23
22
21
20
19
18
17
16
15

1312PARK POWER VDD B

POR DELAY1
VDD SENSE OUT
POWER FAIL THRESHOLD
PARK VOLTAGE PROG
POR
GND
GND
ERROR OUT

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V
V
V

I
I

P

T

Supply Voltage 14 V

S

Input Voltage 0.3V to V

IN

Differential Input Voltage ±V

ID

DC Output Current 1 A

O

Peak Output Current (non repetitive) 1.2 A

p
tot

Total Power Dissipation (T
Storage and Junction Temperature -55 to +150 °C

stg

= 70°C) 1.2

amb

S

S

W
W

PIN FUNCTIONS

Name Function

V

DD

GND Common Ground.

V

ref

ENABLE Input. Logic low will disable IC.

PARK POWER Input Power supply for the parking circuit.

CURRENT SENSE OUT Current sense operational amplifier output.

ERROR AMP IN Error amplifier inverting input.

ERROR AMP OUT Error amplifier output.

SENSE IN Α/Β Input for external sense resistors.

OUT A, B Outputs of the two Power Operational Amplifiers Connections for Voice coil Motor.

PARK External input for parking. Low will activate the park procedure.

PARK VOLTAGE PROGRAM Input to set the park voltage.

POWER FAIL THRESHOLD Supply monitor threshold setting.

LOGIC SUPPLY SENSE Sense the logic supply level

POR Power on reset output. Low will signal to the controller the failure of the logic supply.

POR DELAY Capacitor connection to set the power on reset delay.

LOGIC SUPPLY FILTER Capacitor connection to filter the logic supply ripple

2/8

Power supply.

Voltage Reference.

L6243DS

THERMAL DATA

Symbol Description Value Unit

R

th j-amb

Thermal Resistance Junction - Ambient 77 to 97 °C/W

ELECTRICAL CHARACTERISTICS

(V

S

= 12V, T

= 25°C; unless otherwise specified)

amb

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

S

I

d

T

j

Supply Range 4.5 13.2 V
Quiescent Drain Current 20 mA
Thermal Shutdown Junction

160 °C

Temperature

ERROR AMPLIFIER

I

b

I

OS

V

OS

Gv Large Signal Open Loop Voltage

GBW Gain Bandwidth 3 MHz

G

min

+ Output Source Current 6 mA

I

O

I

O–-

SR Slew-rate 2 V/µs

Input Bias Current 1 µA
Input Offset Current 300 nA
Input Offset Voltage -5 +5 mV

65 dB

Gain

Minimum Voltage Gain 5

Output Sink Current 6 mA

SENSE AM PL I F IE R

RIN, V

A

d

SR Slew-rate 1 V/µs

GBW Gain Bandwidth Product 3 MHz

R

in

CMRR Common Mode Rejection Ratio 55 dB

V

ref

ref Input Impedance

9KΩ

Differential Gain 8 V/V

Sense Input Impedance 1.5 KΩ

POWER OP. AMP.

G

V

V

d

V

off

Voltage Gain 26 dB
Total Output Voltage Drop IO = 250mA

I

= 500mA

O

I

= 1A

O

Offset Voltage on Sense

450
750

1.15 1.5

mV
mV

V

5mV

Resistor

BW Bandwidth on Resistive Load 100 KHz

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