U2860B-M

Features Two Alignment-free PLL FM Demodulators, Automatic Lock-in on the Received Sound Carrier Frequency Mono and Dual Channel Application Sound IF Inputs Provided for Ceramic Filters Automatic Mute for Second Sound Channel (Squelch) Mute Function for Both Sound Channels 5-V Supply Voltage, Low-power Consumption Few External Components Description The U2860B-M is a dual-channel FM sound demodulator realized with Atmel ’s advanced bipolar process. All TV FM standards, from 4.5 MHz up to 6.5 MHz (standard M, B/G, I, D/K) can be processed with high performance. The circuit is alignment-free and has a minimum number of external components. With 5 V supply voltage, the U2860B-M is suitable for TV, VCR and multimedia applications. Dual-Channel FM Sound Demodulator for TV Systems U2860B-M Figure 1. Block Diagram VS 13 Cstab 12 11 Supply Vin1 1 VCO 1 Loop filter 1 Mute 3 Mute VCO offset Vin2 14 VCO 1 Loop filter 2 Squelch 4 Squelch Squelch (second carrier) 8 7 VAF1 10 VCO offset Rref (optional) 6 VAF2 9 Rev. 4794A–TVVCR–02/04 Pin Configuration Figure 2. Pinning Vin1 NC Vmute Vsque NC VAF2 VAF1 1 2 3 4 5 6 7 14 Vin2 13 VS 12 GND 11 Cstab 10 Rref 9 C9 8 C8 Pin Description Pin Symbol 1 Vin1 2 NC 3 Vmute 4 Vsque 5 NC 6 VAF2 7 VAF1 8 C8 9 C9 10 Rref 11 Cstab 12 GND 13 VS 14 Vin2 Function Intercarrier input of sound channel 1 (5.5 MHz) Not connected Mute for sound channel 1+2 “on/off” Automatic mute for 2nd sound channel (squelch) “on/off” Not conne...