1 standard ics 7-channel high current driver BA6257 the BA6257 is a printer hammer solenoid driver for electronic calculators. it consists of seven circuits and is provid- ed with a high input impedance in order to enable direct drive from mos ics. it features a built-in clamp diode and 16-pin dip for easy installation. applications hammer solenoid drivers relay drivers led drivers features block diagram in1 in2 in3 in4 in5 in6 in7 gnd out1 out2 out3 out4 out5 out6 out7 v cc 8 16 15 14 13 12 11 10 1 2 3 4 5 6 7 9 BA6257 1) 7-channel darlington transistor array. 2) high current driver capability of 100ma. 3) can be directly connected to mos ic devices. 4) high withstanding voltage of 38v for input and 24v for output. 5) built-in clamp diode for driving inductive loads.
2 standard ics BA6257 internal circuit configuration 1 16 r 1 r 2 r 3 q1 q2 2 15 r 1 r 2 r 3 q3 q4 3 14 r 1 r 2 r 3 q5 q6 4 13 r 1 r 2 r 3 q7 q8 5 12 r 1 r 2 r 3 q9 q10 6 11 9 8 r 1 r 2 r 3 q11 q12 7 10 r 1 r 2 r 3 q13 q14 r 1 = 25k w r 2 = 25k w r 3 = 2k w d1 d2 d3 d4 d5 d6 d7 fig.1 absolute maximum ratings (ta = 25?) parameter symbol limits unit power supply voltage v cc 24 v power dissipation 500 * mw operating temperature c storage temperature c collector current i c 100 ma input voltage v in v pd ? 25 ~ + 75 ? 55 ~ + 125 ? 0.5 ~ + 38 * reduced by 5mw for each increase in ta of 1 c over 25 c. tstg topr electrical characteristics (unless otherwise noted, ta = 25?, v cc = 20v) parameter symbol min. typ. max. unit conditions measurement circuit usage voltage range (output) v cc 20 v output leakage current i l 100 m av c = 20v, v in = 0v fig.2 1.4 2.2 v i out = 75ma, v in = 17v fig.3 2.2 v i out = 75ma, v in = 8v fig.3 input current i in 0.6 1.4 ma i out = 0ma, v in = 17v fig.4 diode leakage current i r 100 m av r = 20v fig.5 diode forward voltage v in 1.2 vi f = 75ma fig.6 collector saturation voltage 1 collector saturation voltage 2 v ce ( sat ) 1 v ce ( sat ) 2 measurement circuits 8 9 out in a 1 unit fig.2 8 9 out in v 1 unit v v ce (sat) i out fig.3
3 standard ics BA6257 8 9 out i in a 1 unit v in in fig.4 8 9 out in 1 unit ir a fig.5 in out if v 1 unit vf 9 8 fig.6 electrical characteristic curve 120 100 80 60 40 20 0 020406080100 duty cycle (%) maximum output current : i out (ma) 7 circuits operating simultaneously ta = 75 c max. v in = 20v fig.7 output current vs. duty cycle external dimensions (units: mm) dip16 0.51min. 0.3 0.1 9 16 8 1 6.5 0.3 3.2 0.2 4.25 0.3 0.5 0.1 19.4 0.3 2.54 0 ~ 15 7.62
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