10/94 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 full bridge power amplifier uc3176 uc3177 features description the uc3176/7 family of full bridge power amplifiers is rated for a continu- ous output current of 2a. intended for use in dem anding 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. out- put stage protection includes foldback current limiting and thermal shut- down, resulting in a very rugged device. auxiliary functions on this device include a dual input under-voltage com- parator 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 char- acteristics. block diagram
input supply voltage, (+v in ) . . . . . . . . . . . . . . . . . . . . . . . 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 +v in al sink and bl sink 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 . . . . . . . . -55c to +150c power dissipation at tc = +75c qp package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4w storage temperature . . . . . . . . . . . . . . . . . -65c to +150c note 1: unless otherwise indicated, voltages are reference to ground and currents are positive into, negative out of, the specified terminals. parameter test conditions min. typ. max. units input supply supply current +v in = 12v 18 25 ma +v in = 35v 21 30 ma uvol threshold +v in low to high 2.8 3.0 v threshold hysteresis 220 300 mv power, amplifier, a and b input offset voltage v cm = 6v, v out = 6v 8mv input bias current v cm = 6v, except a+ input -500 -100 na input bias current at a+/reference input (a+/ref - bi sink )/36kohms; t j = 25c 23 28 35 m a/v input offset current b amp (uc3176 only) v cm = 6v 200 na cmrr v cm = 1 to 33v, +v in =35v, v out = 6v 70 100 db psrr +v in = 5 to 35v, v cm = 2.5v 70 100 db large signal voltage gain v out = 3v, w/ iout = 1a to v out = 9v, w/ iout = -1a 1.5 4 v/mv thermal feedback +v in = 20v, pd = 20w at opposite output 25 200 m v/w saturation voltage i out = -2a, high side, t j = 25 1.9 v ci out = 2a, low side, t j = 25c 1.6 v total v sat at 2a, t j = 25c 3.5 3.7 v unity gain bandwidth 1mhz slew rate 1v/ m s differential i out sense error current i out (a) = -i out (b), /i out /- /ai sink - bi sink/ in bridge configuration i out 200ma 3.0 6.0 ma i out 2a 5.0 10 ma high side current limiting =v in - v out < 12v -2.7 -2.0 a uc3176 uc3177 absolute maximum ratings (note 1) qp package: thermal resistance junction to leads, q jl . . . . . . 15c/w thermal resistance junction to ambient, q ja . . . . 50c/w thermal data package pin function function pin +v in 1 b output 2 bi sink (sense) 3 bi sink 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 ai sink 25 ai sink (sense) 26 a output 27 gnd 28 * pin 9: uc3176, b+ input uc3177, supply ok plcc-28 (top view) qp package connection diagram electrical characteristics: unless otherwise stated, specifications hold for t a = 0 to 70c, +v in = 12v, t a = t j . 2
parameter test conditions min. typ. max. units current sense amplifier input offset voltage v cm = 0v, a+/ref at 6v 3mv ref = 2v to 20v, +v in = 35, change with ref input voltage 600 m v/v thermal gradient sensitivity +v in = 20v, ref = 10v pd = 20w @ a or b output 5.0 75 m v/w psrr ref = 2.5v, +v in = 5 to 35v 70 100 db gain /ai sink - bi sink / 0.5v 7.8 8 8.1 v/v slew rate 2v/ m s 3db bandwidth 1mhz max output current i source = +v in - v out = 0.5v 2.5 3.5 ma output saturation voltage i source = 1.5ma, high side 0.15 0.30 v i sink = 5ma, low side 1.4 1.7 v under-voltage comparator threshold voltage low to high, other input at 5v 1.44 1.50 1.56 v threshold hysteresis 50 70 80 mv input current input = 2v, other input at 5v -2 -.05 m a supply ok v sat (uc3177 only) i out = 5ma 0.45 v supply ok leakage (uc3177 only) v out = 35v 5 m a park/inhibit park/inhibit thld 1.1 1.3 1.7 v park/inhibit input current at threshold 60 100 m a parking drive saturation voltage i out = 100ma 0.3 0.7 v parking drive leakage v out = 35v 15 m a thermal shutdown shutdown temperature 165 c uc3176 uc3177 electrical characteristics: unless otherwise stated, specifications hold for t a = 0 to 70c, +v in = 12v, t a = t j . output saturation voltage vs current maximum source current vs +v in - v out crossover current error characteristic 3
uc3176 uc3177 transconductance (g o ) = i l v s = r f2 r f1 ? ? 1 8 r s ? ? with: r sa = r sb and r f3 = r f4 parking current (i p ) = v in - 1.5 r p + r l where: r l = load resistance under-voltage thresholds, at supplies high to low threshold, (v lh ) = 1.425 (r a + r b )/r b low to high threshold, (v hl ) = 1.5 (r a + r b )/r b application and operation information design equations waveforms for above application unitrode integrated circuits 7 continental blvd. merrimack, nh 03054 tel. (603) 424-2410 fax (603) 424-3460 4
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