HT8658 Datasheet, PDF (1/15 Pages) Holtek Semiconductor Inc – Voice Recorder (DRAM)

HT8658/HT8659
Voice Recorder (DRAM)
Features
• _{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 inter-
face 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 compo-
nents are required for normal applications.
Each IC can be offered in a dice form or 28 pin
dual-in-line package.
Pin Assignment
AS4 ₁
AS3 ₂
AS2 3
AS1 4
AS0 5
VDD 6
AIN 7
AO 8
BIAS 9
FOUT 10
VSS 11
CAS1B 12
CAS2B 13
CAS3B 14
28 AS5
27 AS6
26 AS7
25 AS8
24 AS9
23 OSC1
22 OSC2
21 DATA
20 RASB
19 WRB
18 RESB
17 RECB
16 PLYB
15 LEDB
HT8658A/8659A
– 28 DIP
AS4 ₁
AS3 ₂
AS2 3
AS1 4
AS0 5
VDD 6
AIN 7
AO 8
BIAS 9
VOUT 10
VSS 11
CAS1B 12
CAS2B 13
CAS3B 14
28 AS5
27 AS6
26 AS7
25 AS8
24 AS9
23 OSC1
22 OSC2
21 DATA
20 RASB
19 WRB
18 RESB
17 RECB
16 PLYB
15 LEDB
HT8658B/8659B
– 28 DIP
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26th Sep ’96