HT8665

HT8665 Talking Back with Echo Features www.DataSheet4U.com Single power supply: 4.5V~5.5V ADM algorithm Auto playback with an echo effect DRAM options: – 64K – 256K Sampling rate options: – 32K bps (bits per second) – 16K bps Recording capacity: 2, 4, 8, 16 seconds A built-in 2 stage microphone amplifier A built-in DRAM refresh circuit A voltage type D/A output A current type D/A output Auto power-off Low power dissipation Applications Toys Educations Games General Description The HT8665 is a single chip CMOS LSI using an ADM algorithm. It is designed for applications on talking back with an echo effect. Functions of the IC consist of recording/playing and auto power off in addition to an echo effect. The IC starts recording when a sound input is detected, and stops to play back when silence lasts 0.5 seconds during recording. The auto power off function is activated once a REC/PLAY cycle has been implemented 64 times or an interval of silence exceeds 2 minutes. The HT8665 provides a recording capacity of 2 seconds at a 32K bps sampling rate for DRAM of 64K (8 seconds for DRAM of 256K) and 4 seconds at a 16K bps sampling rate (16 seconds for DRAM of 256Kb). A higher sampling rate results in sounds of better quality but sacrifices the recording time, and vice versa. 1 21st Dec ’95 HT8665 www.DataSheet4U.com Pin Assignment A0 RASB WRB DATA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 ...