utc cw574 linear integrated circuit utc unisonic technologies co., ltd. 1 qw-r111-008,b 33v color tv voltage regulator description the utc cw574 is a parallel voltage regulator which provides stable harmonious voltage for high frequency tuner head of color tv. features *low temperature coefficient. *low dynamic resister. *typical voltage: 33v. block diagram 1 2 to-92-2 1 2 to-92-2: 1: output 2: gnd pin function pin symbol function 1 gnd ground 2 out output (31~35v) absolute maximum ratings (tamb=25 c) parameter symbol min. max. unit stable current iz 10 ma power dissipation p d 200 mw operating temperature t amb -20 75 c storage temperature t stg -40 125 c
utc cw574 linear integrated circuit utc unisonic technologies co., ltd. 2 qw-r111-008,b electrical characteristics (tamb=25 c) parameter symbol test conditions min typ max unit stable voltage vz iz=5ma 31 33 35 v dynamic resister rz iz=5ma,i ac =0.5ma,f=1khz 10 25 stable current and temperature characteristics ? vz iz=5ma, tamb= -20~75 c -1.0 1.0 mv/ c application circuit 115v rs vi 2 1 33v a r2 r3 r10 r11 r12 tuner control agc bu bv bl aft vt +b ie the utc cw574 is a parallel voltage regulator which provides stable harmonious voltage for high frequency tuner head of color tv. the main power 115v goes through rs resister to position 2 of utc cw574 then the position a with 33v provides stable voltage for control circuit of high frequency tuner. the circuit from r3 to r10 is potential meter for tuning, according to different channels to change contact positions; to provide corresponding voltage to tuner; and to control the capacity of varicap diode in order to have high frequency tuner into proper channel. the voltage range of utc cw574 is required to cover necessary frequency range, and main issue of utc cw574 is its reliable voltage stability which avoids unexpected frequency offset; therefore, the circuit of utc cw574 contains temperature compensation to have lowermost temperature coefficient .
|
