low-saturation, current-controlled bidirectional motor driver overview the lb1843v is a low-saturation bidirectional motor driver with output current limitation and detection functions. this design is ideal for controlling the loading motor in a video camera. features . output current limiter and detector built in . low-saturation voltage bidirectional bridge circuit built in: v o sat = 0.40 v typ. at 400 ma . practically no current drain (0.1 a or less) in standby mode . input-linked reference voltage built in . thermal shutdown circuit built in . requires little space, since few external components are needed and the ic is contained in a small ssop-20 package package dimensions unit : mm 3179a-ssop20 [lb1843v] sanyo : ssop20 specifications absolute maximum ratings at ta = 25c parameter symbol conditions ratings unit maximum supply voltage v cc max 10.5 v maximum output current im max 800 ma applied input voltage v in 0.3 to +10 v allowable power dissipation pd max with board ( 50 35 1.6 mm 3 ) 800 mw operating temperature topr 20 to +80 c storage temperature tstg 40 to +150 c allowable operating ranges at ta = 25c parameter symbol conditions ratings unit supply voltage v cc 3.0 to 9.0 v v m voltage v m 2.2 to v cc v high-level input voltage v ih 3.0 to 9.0 v low-level input voltage v il 0.3 to +0.7 v lir input voltage v lir 0.5 to v cc 1.0 v output current limitation i limit 50 to 350 ma ordering number: en 4385b monolithic digital ic lb1843v sanyo electric co.,ltd. semiconductor bussiness headquarters tokyo office tokyo bldg., 1-10, 1 chome, ueno, taito-ku, tokyo, 110-8534 japan o3096ha(ii) no.4385-1/6
electrical characteristics at ta = 25c, v cc = 7.2 v parameter symbol conditions min typ max unit supply current i cc 0 during standby 0.1 10 a i cc 1 during bidirectional operation, no load 9 13 ma i cc 2 during braking 12 18 ma output saturation voltage vsat1 i o = 200 ma (upper side + lower side) 0.20 0.30 v vsat2 i o = 400 ma (upper side + lower side) 0.40 0.60 v reference voltage vref i v ref = 1 ma 1.85 2.0 2.15 v set output current i limit resistance between v cc and v m =1 w , when lir = 2 v 165 185 205 ma input current i in v in = 5 v 90 150 a rd saturation voltage v rd sat i o = 1 ma 0.3 v output current limit is determined by the following equation (r f is the sensing resistance between v cc and v m ): i limit =v lir /10r f (a) the input range for v lir is 0.5 to v cc 1.0 (v) pd max ta specified board (50 35 1.6 mm 3 glass epoxy) allowable power dissipation, pd max mw ambient temperature, ta c lb1843v no.4385-2/6
block diagram and sample application ciruit pin assignment thermal shut down decoder limit detection v cc = 3 to 10.5 v r f = 0.47 to 2 w 0.001 f to 0.01 f top view notes: . connect both v m pins (motor power supply/sensing pins). . connect both p-gnd pins (motor power supply gnd pins). . connect s-gnd (control power supply gnd pin) to the microcontroller's gnd. lb1843v no.4385-3/6
truth table input output mode in1 in2 out1 out2 l l off off standby hlhl forward lhlh reverse h h l l brake output current limitation and detector output del out output rd h limit l non-limit off l saturated off sample application timing chart sample application timing chart 1 connect a dc motor (r l =r w ) between out1 and out2, and with the rd pin pulled up, input a forward rotation signal (in1 = high, in2 = low). because the output is used in the saturated state at startup, set the del input to low. 2 the dc motor starts up, and the startup current (i st =v m /r) flows to the motor. 3 the dc motor rotates in the normal state. at this point, set the del input to high. 4 if the dc motor locks, the motor current i m increases to the point of i limit (= v lir /(10r f )), the output current limiter operates to limit the output current. at the same time, rd is output low from the set current detection circuit. lb1843v no.4385-4/6
reference voltage (vref) the vref output is linked to the input; if either in1 or in2 is high, the reference voltage is output. output current limiter the schematic for the output current limiter is shown below. the output set current is set according to the reference voltage v lir applied to the lir pin. when v lir is applied, 1/10 of that voltage is generated at both ends of r s in the diagram; this voltage is input on the positive (+) side of the current setting amplifier. the motor current i m generates voltage equal to (i m r f ) at both ends of the external resistor r f . this voltage is input to the negative () side of the same amplifier, and the differential amplifier functions and the output transistors are driven so that these inputs become equal. the set current value in this instance is determined by the following equation: i limit =v lir /(10r f ) [a] set current detector (1) when del = high if the motor current i m has not reached the set current i limit , the input voltage on the negative () side of the amplifier is greater than the input voltage on the positive (+) side. as a result, the drive current increases and the output pnp transistors reach the saturation state. if this state is detected, the detection signal is sent to the set current detector, and the rd output goes high. if the motor current i m reaches the set current i limit , the output pnp transistor enters the controlled state, and the rd output goes low. (2) when del = low because the operation of the current setting amplifier is cancelled when a low signal is input to the del pin, the output pnp transistors reach the saturation state and the rd output goes high, just as in the case described above. the following table summarizes the states described above. del out rd h limit l non-limit (saturated) h l saturated h output current limiter and set current detector block diagram set current detector lb1843v no.4385-5/6
no products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. anyone purchasing any products described or contained herein for an above-mentioned use shall: 1 accept full responsibility and indemnify and defend sanyo electric co., ltd., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: 2 not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on sanyo electric co., ltd., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. sanyo believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. this catalog provides information as of october, 1996. specifications and information herein are subject to change without notice. i cc v cc current drain, i cc ma r f = 0.5 w , no load brake bidirec- tional supply voltage, v cc v i in v in input current, i in a input voltage, v in v i limit v lir set output current, i limit ma v lir v i limit v cc set output current, i limit ma supply voltage, v cc v v o (sat) i o output saturation voltage, v o (sat) v output current, i o ma v o (sat) ta output saturation voltage, v o (sat) v ambient temperature, ta c lb1843v no.4385-6/6
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