HT8658

HT8658/HT8659 Voice Recorder (DRAM) Features www.DataSheet4U.com Single power supply: 4.5V~5.5V ADM coding algorithm DRAM options: – 4×256K bits – 3×1M bits A built-in 2 stage MIC amplifier A built-in low pass filter Data rate options (bits per second): – 32K bps – 22K bps – 16K bps – 11K bps A status LED indicator Auto playback Applications Message box Recorder Toys General Description The HT8658/HT8659 are single chip CMOS LSIs using an ADM coding technology. They are designed for applications on recording sounds. The HT8658 and HT8659 have almost the same functions apart from the reset time. The reset time of the HT8658 has to be over 4 seconds but of the HT8659 over 2 seconds. Blocks within each chip include a DRAM interface circuit, signal amplifier, 8 bit ADC and internal low pass filter. Encoded data are stored in external DRAMs and played back after the PLYB pin be triggered. Each IC provides four kinds of sampling rate to be selected, namely 32K/22K/16K/11K bps (bits per second). A higher sampling rate results in sounds of better quality but sacrifices the recording time. With such a powerful built-in circuit, only few components are required for normal applications. Each IC can be offered in a dice form or 28 pin dual-in-line package. Pin Assignment AS4 AS3 AS2 AS1 AS0 VDD AIN AO BIAS FOUT VSS CAS1B CAS2B CAS3B 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 AS5 AS6 AS7 AS8 AS9 OSC1 OSC2 DATA RASB WRB RESB...