KA2224B dual eq amp with alc general description the KA2224B is a monolithic integrated circuit consisting of a dual equalizer amplifier with alc, and it is suitable for stereo radio cassettes. features dual equalizer amplifier with a built-in alc circuit. recording amp available because of high gain characteristic (variable monitor possible). good channel separation (cs = 50db typ). quick stabilization after power on. capable of direct meter driving and alc transistor. good alc response balance between channels. wide operating supply voltage range: v =4v ~ 13v ordering information block diagram fig. 1 device package operating temperature KA2224B 14-dip-300 -20 c ~ +70 c 1 2 3 4 5 6 7 8 9 10 11 12 13 14 + _ + _ alc2 alc1 vcc output2 comp2 nf2 input2 alc out2 cecouple gnd output1 comp1 nf1 input1 alc out1 alc input 14-dip-300
KA2224B dual eq amp with alc absolute maximum ratings (ta =25 c ) characteristic symbol value unit supply voltage power dissipation operating temperature storage temperature alc tr maximum current v cc p d t opr t stg 14 600 -20 ~ +70 -40 ~ +125 3.5 v mw c c ma electrical characteristics (ta =25 c, v cc =5v, r l =10k w , f =lkhz: play, r l =68 w : recording) characteristic symbol test conditions min typ max unit quiescent circuit current i ccq v i = 0 4.5 10 ma open loop voltage gain g vo 85 db g vc1 play 40 db g vc2 record 58 db output voltage v o thd =1%, play 0.9 1.2 1.0 v total harmonic distortion thd v o = 0.5v, play 0.1 % input resistance r i 21 30 k w equivalent input noise voltage v ni bw (-3db) = 20hz ~ 20khz 1.0 2.0 m v cross talk ct r g = 2.2k w 40 50 db alc range d v alc v i = -60dbm, record 35 45 db alc balance cb alc v i = -20dbm, record 0 2.0 db alc distortion thd alc v i = -20dbm, record 0.5 2.0 % closed loop voltage gain
KA2224B dual eq amp with alc test circuit fig. 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 KA2224B 10k p 680 r r p 4.7k 56 10u 0.033u 22u 4.7u 2.2k in2 220u out2 vcc 220u out1 51k r p 4.7k 0.033u p 10k 680 p r 22u 56 680 4.7u 300k 4.7u 680 4.7u 2.2k in1 4.7u in60x2 in60x2 r p r
KA2224B dual eq amp with alc application information 1. closed loop voltage gain fig. 3. sw on: play off : record a. playback amplifier gv = 20 log (db) at f =1khz, g v = 42db (typ) z = r 1 //(r 2 + ) b. recording ampilfier gv =20 log (db) at f =1khz, g v = 58db (typ) 2. alc circuit fig. 4 the alc circuit consists of tr 1 , tr 2 and some external component. the output level of the amplifier is recti - fied by external circuits. since this dc level is applied to the alc input terminal (pin 7), the impedance between the collector and emitter of tr 1 can change its value, therefore the pre-amplifier input level can be controlled. 2 4 z r 1 51k r 2 4.7k c 2 0.033u c 3 10u r l r f 56 c1 22u 5 7 6 2 input r 1 c 1 c 4 r l r 2 c 2 d 1 d 2 c 3 r 3 r 4 tr 2 tr 1 amp z r f r f r1 1 2 e f c 2
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