isd1740a Winbond Electronics Corp America, isd1740a Datasheet - Page 11

• Manufacturer Part Number: isd1740a
• Description: Multi-message Single-chip Voice Record&playback Devices
• Manufacturer: Winbond Electronics Corp America

6 FUNCTIONAL DESCRIPTION
Confidential
6.1 D
The memory array provides storage for four special Sound Effects (SE) and the audio data. The
memory array is addressed by rows. A row is the minimum storage resolution by which the
memory can be addressed. The memory assignment is handled automatically by the internal
message management system.
The four sound effects occupy four rows of the first sixteen rows in the memory array. The
minimum storage resolution varies with the sampling frequency, as shown in Table 6.2.
Table 6.2 Minimum Storage Resolution vs. Sampling Frequency
For example, at 8 kHz sampling frequency, the minimum storage resolution is 125 msec, so, each
Sound Effect (SE) is approximately 0.5 seconds long. The remaining memory is dedicated to audio
data storage.
6.2 M
Sampling Frequency
Minimum Storage Resolution
6.1.1
Winbond’s patented ChipCorder
high-quality record and playback solution on a single chip. The input voice signals are stored
directly in the Flash memory and are reproduced in their natural form without any of the
compression artifacts caused by digital speech solutions.
6.1.2
The ISD1740A/50A/60A devices offer record and playback duration from 26 seconds to 120
seconds. Sampling rate and message duration are determined by an external resistor
connected to the R
Table 6.1 Duration vs. Sampling Frequency
6.1.3
The ISD1740A/50A/60A devices utilize embedded Flash memory to provide non-volatile
storage. A message can be retained for a minimum of 100 years without power. Additionally,
each device can be re-recorded over 10,000 times (typical).
ETAILED
Sample Rate
EMORY
6.4 kHz
5.3 kHz
12 kHz
8 kHz
4 kHz
Audio Quality
Message Duration
Flash Storage
A
RRAY
D
ESCRIPTION
A
RCHITECTURE
OSC
ISD1740A
pin.
26 sec
40 sec
50 sec
60 sec
80 sec
83.3 msec
®
12 kHz
Multi-Level Storage (MLS) technology provides a natural,
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ISD1750A
100 sec
33 sec
50 sec
62 sec
75 sec
125 msec
8 kHz
Publication Release Date: March 28, 2005
156 msec
ISD1700A SERIES
6.4 kHz
ISD1760A
120 sec
40 sec
60 sec
75 sec
90 sec
187 msec
5.3 kHz
Revision A0
250 msec
4 kHz