UNITRODE UC3173A Technical data

UC3173A

Full Bridge Power Amplifier

FEATURES

• Precision Current Control

•

±

500mA Load Current

• 1.3V Typical Total V

SAT

at 550mA

• Controlled Velocity Head Parking

• Precision Dual Supply Monitor with

Indicator

• Range Control for 4:1 Gain Change

• Compensation Adjust Pin for

Bandwidth Control

• Inhibit Input and UVLO

• 5V or 12V Operation

• 12mA Quiescent Supply Current

• PLCC, SOIC, and Low Profile Quad

Flat Pack Packages

DESCRIPTION

This full bridge power amplifier, rated for continuous output current of

0.55A, is intended for use in demanding servo applications such as head

positioning for high density disk drives. This device includes a precision cur-

rent sense amplifier that senses load current with a single resistor in series

with the load. The UC3173A is optimized to consume a minimum of supply

current, and is designed to operate in both 5V and 12V systems. The power

output stages have a low saturation voltage and are protected with current

limiting and thermal shutdown. When inhibited the device will draw less

than 1.5mA of total supply current.

Auxiliary functions on this device include a dual input undervoltage com-

parator, which can monitor two independent supply voltages and activate

the built in head park function when either is below minimum. The park cir-

cuitry allows a programmable retract voltage to be applied to the load for

limiting maximum head velocity. A separate low side parking drive pin per-

mits a series impedance to be inserted to control maximum retract current.

The parking drive function can be configured to operate with supply volt-

ages as low as 1.2V.

The closed loop transconductance of the configured power amplifier can be

switched between a high and low range with a logic input. The 4:1 change

in gain can be used to extend the dynamic range of the servo loop. Band-

width variations that would otherwise result with the gain change can be

controlled with a compensation adjust pin.

BLOCK DIAGRAM

04/99

UDG-94039

查询UC3173ADW供应商

2

UC3173A

Input Supply Voltage, (VIN, VC, VL) . . . . . . . . . . . . . . . . . . 20V

UV Comparator

Maximum Forced Voltage . . . . . . . . . . . . . . . . −0.3V to 10V

Maximum Forced Current. . . . . . . . . . . . . . . . . . . . .

±

10mA

B Amplifier Inverting Input . . . . . . . . . . . . . . −0.3V to VIN + 1.0

A Amplifier Inverting Inputs,

(Aux. and Normal) . . . . . . . . . . . . . . . . . −0.3V to VC + 1.0V

Open Collector Output Voltages . . . . . . . . . . . . . . . . . . . . . 20V

A and B Output Currents (Continuous)

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

Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6A

Parking Drive Output Current

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

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

Output Diode Current (Pulsed). . . . . . . . . . . . . . . . . . . . . . 0.6A

Power OK Output Current (Continuous). . . . . . . . . . . . . . 30mA

Operating Junction Temperature . . . . . . . . . . −55°C to +150°C

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

Lead Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C

Note 1: Unless otherwise indicated, voltages are referenced to

ground and currents are positive into, negative out of, the speci-

fied terminals, “Pulsed” is defined as a less than 10% duty cycle

pulse with a maximum duration of 500

µ

s.

ABSOLUTE MAXIMUM RATINGS (Note 1)

DW Package:

Thermal Resistance Junction to Leads, θjl . . . . . . . . 35°C/W

Thermal Resistance Junction to Ambient, θja . . . . 60-70°C/W

FQ Package:

Thermal Resistance Junction to Leads, θjl. . . . . . . . . 60°C/W

Thermal Resistance Junction to Ambient, θja . . 110-120°C/W

QP Package:

Thermal Resistance Junction to Leads, θjl. . . . . . . . . 15°C/W

Thermal Resistance Junction to Ambient, θja . . . . 30-40°C/W

Note 2: The above numbers for

θ

jl are maximums for the limiting

thermal resistance of the package in a standard mounting con-

figuration. The

θ

ja numbers are meant to be guide lines for the

thermal performance of the device/pc-board system. All of the

above numbers assume no ambient airflow.

Note 3: Consult Packaging Section of Unitrode Integrated Cir-

cuits databook for thermal specifications and limitations of pack-

ages.

THERMAL DATA

SOIC-24 (Top View)

DW Package

PLCC-28 (Top View)

QP Package

48

47

46

45

1

44

43

42

41

40

39

38

37

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

36

35

34

33

32

31

30

29

28

27

26

25

N/C

N/C

VIN

BIN

N/C

N/C

PRKDRV

PWROK

REFIN

N/C

N/C

N/C

BOUT

BOUT

N/C

N/C

N/C

AOUT

AOUT

N/C

N/C

N/C

AIN

VC

RANGE

CS+

COMP

VP ARK

N/C

GND

CSOUT

VL

INH

N/C

UV1

UV2

PARK

PGND

N/C

PGND

CS–

N/C

N/C

N/C

N/CN/C

N/C

N/C

CONNECTION DIAGRAMS

TQFP-48 (Top View)

FQ Package

3

UC3173A

ELECTRICAL CHARACTERISTICS:

Unless otherwise stated, these specifications apply for T

A

= 0 to +70°C, VIN = 5V,

VC = VIN = VL, REFIN = VIN/2, RANGE, PARK, and INH = 0V, and T

A

=T

J

.

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Input Supply

VIN Supply Current 10 13 mA

VC Supply Current I

OUT

= 0A 1.2 2.0 mA

VL Supply Current 0.65 1.0 mA

Total Supply Current Supplies = 5V, I

OUT

= 0A 12 16 mA

Supplies = 12V, I

OUT

= 0A 13 18 mA

VL UVLO Threshold Low to High 2.6 2.8 V

UVLO Threshold Hysteresis 300 mV

Under Voltage (UV) Comparator

Input Bias Current Max at Either UV Input −0.25 −1.0 µA

UV Thresholds Low to High, Other Input = 5V 1.28 1.3 1.32 V

UV Threshold Hysteresis 19 24 29 mV

PWROK Vsat I

OUT

= 5mA, UV Input Low 0.15 0.45 V

PWROK Leakage V

OUT

= 20V 5 µA

Power Amplifiers A and B

Input Offset Voltage A Amplifier, V

CM

= 2.5V 4 mV

B Amplifier, V

CM

= 2.5V 12 mV

Input Bias Current V

CM

= 2.5V, Inverting Inputs Only −150 −500 nA

Input Bias Current at Ref. Input (REFIN − CS+)/48kΩ,T

J

= 25°C 152127µA/V

CMRR V

CM

= 1V to 10V, Supplies = 12V 70 90 dB

PSRR VIN = 4V to 15V, V

CM

= 1.5V 70 90 dB

Large Signal Voltage Gain Supplies = 12V, V

OUT

= 1V, I

OUT

= 300mA to

V

OUT

= 11V, I

OUT

= −300mA

3.0 15.0 V/mV

Gain Bandwidth Product A Amplifier (Note 4) 2.0 MHz

B Amplifier (Note 4) 1.0 MHz

Slew Rate (Note 4) 1.0 V/µs

High-Side Current Limit Low Range Mode 0.6 0.8 A

High Range Mode 1.1 1.6 A

Output Saturation Voltage High-Side, I

OUT

= −100mA (Note 5) 0.7 V

High-Side, I

OUT

= −300mA (Note 5) 0.8 V

High-Side, I

OUT

= −550mA (Note 5) 0.95 V

Low-Side, I

OUT

= 100mA 0.2 V

Low-Side, I

OUT

= 300mA 0.25 V

Low-Side, I

OUT

= 550mA 0.35 V

Total V

SAT

,I

OUT

= 100mA 0.9 1.2 V

Total V

SAT

,I

OUT

= 300mA 1.05 1.4 V

Total V

SAT

,I

OUT

= 550mA 1.3 1.7 V

VC to VIN Headroom Volts below VIN, delta High-Side, V

SAT

= 100mV, I

OUT

= −550mA (Note 5)

0.23 0.4 V

High-Side Diode, V

F

I

D

= 550mA 1.0 V

Low-Side Diode, V

F

I

D

= 550mA, INH Activated, B Amplifer Only 1.0 V

4

UC3173A

ELECTRICAL CHARACTERISTICS:

Unless otherwise stated, these specifications apply for T

A

= 0 to +70°C, VIN = 5V,

VC = VIN = VL, REFIN = VIN/2, RANGE, PARK, and INH = 0V, and T

A

=T

J

.

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Current Sense Amplifier

Input Offset Voltage V

CM

= 2.5V, Low range mode 2.0 mV

V

CM

= 2.5V, High range mode 4.0 mV

Input Offset Change with Common

Mode Input

V

CM

= –1V to 13V, Supplies = 12V, Low Range Mode 2000 µV/V

V

CM

= –1V to 13V, Supplies = 12V, High Range Mode 4000 µV/V

Voltage Gain V

DIFF

= +1.0 to −1.0V, V

CM

= 2.5V, High Range Mode 0.485 0.50 0.515 V/V

V

DIFF

= +1.0 to −1.0V, V

CM

= 2.5V, Low Range Mode 1.95 2.0 2.05 V/V

Saturation Voltage Low-Side, I

OUT

= 1mA 0.1 0.3 V

High-Side, I

OUT

= −1mA, Referenced to VIN 0.1 0.3 V

Parking Function

Park Input Threshold Voltage 0.6 1.1 1.7 V

Park Input Threshold Current Internal Pull-Up, VIN = 0.6V 50 75 µA

Park Drive Saturation Voltage I

OUT

= 50mA 0.15 0.35 V

Park Drive Leakage V

OUT

= 20V 50 µA

Regulating Voltage at Park Volts Input 1.275 1.30 1.325 V

Amplifier A Auxiliary Input Bias Current −300 −750 nA

Amplifier A Parking High-Side

Saturation Voltage

I

OUT

= −50mA, VIN = 0V, VC = VL = 5V, PARK Open,

VC to V

OUT

0.8 0.95 V

Minimum Parking Supply At VC and VL, VIN = 0V,

A Amplifier Out - V

SAT

PRKDRV > 0.5V, I

PARK

=

50mA

1.4 1.7 V

Minimum Supply for Parking Drive and

Power OK Operation

At VL, VC = VIN = 0V, V

SAT

< 0.5V,

I

OUT

PRKDRV = 50mA, Rl = 30Ω to 2V

1.1 1.4 V

I

OUT

PWROK = 5mA, Rl = 300Ω to 2V 1.2 1.6 V

VL Parking Supply Current PARK Open, VL = 5V, VC = 1.6V, VIN = 0V,

PWROK I

OUT

= 5mA, PRKDRV I

OUT

= 50mA

1.6 3.0 mA

Auxiliary Functions

Inhibit Input Threshold 0.6 1.1 1.7 V

Inhibit Input Current INH = 1.7V −0.5 −1.0 µA

Range Input Threshold 0.6 1.1 1.7 V

Range Input Current RANGE = 1.7V 50 100 µA

Comp Adjust Pin Saturation Voltage RANGE = 0V, Pin Current = ±500µA,

Referenced to A

OUT

0.02 0.1 V

Comp Adjust Leakage Current RANGE = 1.7V, Supplies = 12V,

A

OUT

-V

COMP

= ±6V

5 µA

Total Supply Current when Inhibited VIN, VC, and VL currents 1.0 1.5 mA

Thermal Shutdown Temperature (Note 4) 165 °C

Note 4: Guaranteed by design. Not 100% tested in production.

Note 5: The high-side saturation performance of the UC3173A is referenced to the VIN supply pin.

The VC supply pin can operate about 400mV below the VIN supply input without affecting the performance.