AF103

~National ~ Semiconductor Active Filters AF103 Low Band Splitter General Description The AF103 is a fourth order elliptic low pass filter designed to reject frequencies above 1200 Hz and pass signals· below 950 Hz. This filter is used to separate the low band of frequencies from the high band in a Dual Tone Multi Frequency (DTMF) Touch Tone® receiver. The unit is fully tuned and requires no external components - only power supply, input and output connections. Features Fully tuned High input impedance Low output impedance Wide power supply range Connection Diagram ~ 121 HP2 -IN2 ijUTPUTllPl -11.11 HP2 111 111 ~ NC 241 23 22 21 20 19 18 17 16 15\14 13\ I ±5V to ±18V 4th ORDER lOW PASS elLIPTIC FilTER J l I10 111 121 ru122 Q2 Ql~. 112 BPI NC NC Ceramic Dual-In-Line Package HY24A AF103CJ Note: Only those pin functions marked with a 0 need be connected for normal operation. All other pins are internal connections or test points; DO NOT USE. 14-26 ® Regist...