UNITRODE UC3176, UC3177 Technical data

UC3176QP

UC3176

UC3177

Full Bridge Power Amplifier

FEATURES

∙Dual Power Operational Amplifiers

∙±2A Output Current Guaranteed

∙Precision Current Sense Amplifier

∙Two Supply Monitoring Inputs

∙Parking Function and Under-Voltage Lockout

∙Safe Operating Area Protection

∙3V to 35V Operation

DESCRIPTION

The UC3176/7 family of full bridge power amplifiers is rated for a continuous output current of 2A. Intended for use in demanding servo applications such as disk head positioning, the onboard current sense amplifier can be used to obtain precision control of load current, or where voltage mode drive is required, a standard voltage feedback scheme can be used. Output stage protection includes foldback current limiting and thermal shutdown, resulting in a very rugged device.

Auxiliary functions on this device include a dual input under-voltage comparator that can be programmed to respond to low voltage conditions on two independent supplies. In response to an under-voltage condition the power Op-Amps are inhibited and a high current, 100mA, open collector drive output is activated. A separate Park/Inhibit command input.

The devices are operational over a 3V to 35V supply range. Internal un- der-voltage lockout provides predictable power-up and power-down characteristics.

BLOCK DIAGRAM

10/94

ABSOLUTE MAXIMUM RATINGS (Note 1)

Input Supply voltage, (+VIN) . . . . . . . . . . . . . . . . . . . . . . . 40V Park/Inhibit, UV1 and UV2 inputs (zener clamped)

Maximum forced voltage . . . . . . . . . . . . . . . . -0.3V to 10V Maximum forced current. . . . . . . . . . . . . . . . . . . . . ±10mA Other Input Voltages. . . . . . . . . . . . . . . . . . . . . -0.3V to +VIN AlSINK and BlSINK Voltages . . . . . . . . . . . . . . . . . . -0.3V to 6V Open Collector Output Voltages. . . . . . . . . . . . . . . . . . . . 40V

A and B Output Currents (Continuous)

Source . . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Sink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5A Total Supply Current (Continuous). . . . . . . . . . . . . . . . . . . 4A Parking Drive Output Current (Continuous) . . . . . . . . 200mA Supply OK Output Current, UC3177 (Continuous) . . . 30mA Operating Junction Temperature . . . . . . . . -55°C to +150°C

Power Dissipation at TC = +75°C

QP package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4W Storage Temperature . . . . . . . . . . . . . . . . . -65°C to +150°C

Note 1: Unless otherwise indicated, voltages are reference to ground and currents are positive into, negative out of, the specified terminals.

THERMAL DATA

QP package:

Thermal Resistance Junction to Leads, θJL . . . . . . 15°C/W Thermal Resistance Junction to Ambient, θJA . . . . 50°C/W

			UC3176
			UC3177
	CONNECTION DIAGRAM
	PLCC-28 (Top View)	PACKAGE PIN FUNCTION
		FUNCTION	PIN
	QP Package
		+VIN	1
		B Output	2
		BISINK(Sense)	3
		BISINK	4
		N/C	5-7
		B- Input	8
		*	9
		Park/Inhibit	10
		Parking Drive	11
		Gnd (Heat Flow Pins)	12-18
		UV1	19
		UV2	20
		Current Feedback	21
		A+ Input	22
		A- Input	23
		N/C	24
		AISINK	25
		AISINK(Sense)	26
		A Output	27
		Gnd	28

*Pin 9: UC3176, B+ Input

UC3177, Supply OK

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, specifications hold for TA = 0 to 70°C, +VIN = 12V, TA = TJ.

PARAMETER	TEST CONDITIONS	MIN.	TYP.	MAX.	UNITS
Input Supply
Supply Current	+VIN = 12V		18	25	mA
	+VIN = 35V		21	30	mA
UVOL Threshold	+VIN low to high		2.8	3.0	V
	Threshold Hysteresis		220	300	mV
Power, Amplifier, A and B
Input Offset Voltage	VCM = 6V, VOUT = 6V			8	mV
Input Bias Current	VCM = 6V, Except A+ Input	-500	-100		nA
Input Bias Current at A+/Reference Input	(A+/Ref - BISINK)/36kohms; TJ = 25°C	23	28	35	μA/V
Input Offset Current B Amp (UC3176 Only)	VCM = 6V			200	nA
CMRR	VCM = 1 to 33V, +VIN =35V, VOUT = 6V	70	100		dB
PSRR	+VIN = 5 to 35V, VCM = 2.5V	70	100		dB
Large Signal Voltage Gain	VOUT = 3V, w/IOUT = 1A to VOUT = 9V, w/IOUT = -1A	1.5	4		V/mV
Thermal Feedback	+VIN = 20V, Pd = 20W at opposite output		25	200	μV/W
Saturation Voltage	IOUT = -2A, High Side, TJ = 25°		1.9		V
	CIOUT = 2A, Low Side, TJ = 25°C		1.6		V
	Total VSAT at 2A, TJ = 25°C		3.5	3.7	V
Unity Gain Bandwidth			1		MHz
Slew Rate			1		V/μs
Differential IOUT Sense Error Current	IOUT(A) = -IOUT(B), /IOUT/- /AISINK - BISINK/
in Bridge Configuration	IOUT ≤200mA		3.0	6.0	mA
	IOUT ≤ 2A		5.0	10	mA
High Side Current Limiting	=VIN - VOUT < 12V		-2.7	-2.0	A

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