Texas Instruments UC3175BQP, UC3175BQPTR, UC3175BDWTR, UC3175BDW Datasheet

10/94

Note: Pin numbers refer to PLCC packag e.

BLOCK DIAGRAM

• Precision Current Control

•

±

800mA Load Current

• 1.25V Total V

SAT at 800mA

• Controlled Velocity Head Parking

• Precision Dual Supply Monitor

with Indicator

• Limit Input to Force Output
Extremes

• Inhibit Input and UVLO

• 4V to 15V operation

This full-bridge power amplifier is rated for continuous output current of 0.8 Am­peres and is intended for use in demanding servo applications such as head
positioning for high-d ensi ty disk drives. The device includes a precision current
sense amplifier that provides accurate control of load current. Current is
sensed with a single resi s tor in seri es with the load. The power amplifier has a
very low output saturation voltage and will operate down to 4V supply levels.
Power output stage protection includes current l imiting and thermal shutdown.

Auxiliary functions on this device include a dual-input under-voltage compara­tor, which can monitor two independent supply voltages and force a built-in
head park function when either is below minimum. When activated by e ither the
UV comparator, or a command at the separate PARK input, the park circuitry
will override the amplifier i nputs to convert the power outputs to a programma­ble constant voltage source which will h old regula tion as th e supply voltage
falls to below 3.0 Volts. Added features include a POWER OK flag output, a
LIMIT input to force the drive output to its maximum level in either polarity, and
a over-riding INHIBIT input to disable al l amplifiers and reduce quiescent sup­ply current.

This device is packaged in a power PLCC surface mount configuration which
maintains a standard 28-pin outline, but with 7 pins along one edge allocated to
ground for optimum thermal transfer. And is also available in a 24-pin surface
mount SOIC package.

UC3175B

Full-Bridge Power Amplifier

FEATURES DESCRIPTION

UDG-92054-1

CONNECTION DIAG RAMS

UC3175B

PACKAGE PIN FUNCTION

FUNCTION PIN

+VIN 1
INH 2
UV2 3
UV1 4
Limit 5
Park Volts 6
C/S- 7
A+/REF Input 8
A- In 9
A Output 10
A Cur Sen 11
Gnd (Heat Dissipat io n Pins) 12-18
B Cur Sen 19
B Output 20
+V

C Supply 21

B- In 22
B+ In 23
C/S+ 24
Pwr OK 25
Park 26
Park Drive 27
C/S Out 28

PLCC-28 (Top View)
QP Package

ABSOLUTE MAXIMUM RATINGS

Input Supply Vo ltag e, (+VIN,+VC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V

UV Comparator, and Digital Input s

Maximum forced vo ltag e. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 10V

Maximum forced cu rrent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10mA

C/S Inputs

Maximum forced vo ltag e. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 20V

A and B Amplifier Inpu ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +V

IN

Open Collector Out put Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V

A and B Output Curren ts (continu ous)

Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited

Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0A

Parking Drive Output Curr ent

Continuous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150mA

Pulsed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A

Output Diode Current (pulsed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A

Power OK Output Cu rrent (c ont inuou s) . . . . . . . . . . . . . . . . . . . . . . . . . 30mA

Operating Jun ctio n Tem per atur e. . . . . . . . . . . . . . . . . . . . . . -55°C to +150 °C

Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C

Note 1: Unless other w ise indicat ed, volt age s are
reference d to grou nd and current s are pos itive
into, negat ive out of, the sp ecif ied te rminals.
"Pulsed" is defined as a less than 10% duty cycle
pulse with a maximum dur ation of 500µs.
Note 2: See Unitrode Int egr at ed Circ uits databoo k
for informat ion regarding thermal specif ic atio ns
and limitat ions of packages.

PARAMETER TEST CONDITION S MIN TYP MAX UNITS

INPUT SUPPLY

+V

IN Supply Current All Amplifier Outpu ts = 6V 35 42 mA

+V

C Supply Current IOUT = 0A 1 mA

+V

IN UVLO Threshold Low to High 2.8 3.0 V

UVLO Threshold Hysteresis 200 mV

ELECTRICAL CHARACTERISTICS:

Unless otherwise stated spec ifications apply for 0°C ≤ TA ≤ 70°C, +VIN = 12V, +VC
= +VIN, A+/REF Inp ut = 6 V. TA=TJ.

SOIC-24 (Top View)
DW Package

Thermal Data

QP Package:

Thermal Resistance Junction to Leads,
θ

JL . . . . . . . . . . . . . . . . . . . . . . . 15°C/W

Thermal Resistance Junction to Ambient,
θ

JA . . . . . . . . . . . . . . . . . . . . . . . 40°C/W

2