Example #2:
ISD1700A SERIES
vAlert
S1
24 REC
S2
23 PLAY
S3
25 ERASE
R1
D1
LED 2 1 K Ω
VCC
Vcc
Gnd
S4
26 FWD
S5
19 VOL
S6
3
VCCD 1
VSSD 28
C4
0.1 µF
VCCD
C8 *
***
VCCA
VCCD
VCCP
***
S7
Vcc
RESET
22 FT
7 TE3
6 TE2
5 TE1
ISD1740A
ISD1750A
VCCA 21
VSSA 8
VCCP 14
VSSP1 16
VSSP2 12
C5
0.1µ F
VCCP
C6
0.1µF
C7
C10 * 0.1 µ F
VCCA
C9 *
C11 *
4 NC ISD1760A
10 MIC+
11 MIC -
SP+ 15
SP- 13
Speaker
or Buzzer
VCC
Speaker
C2
0.1 µ F 9 ANA IN
R2 **
20
18
C1
4.7 µF
ROSC
AGC
AUD 17
RDY 27
390 Ω
Q1
8050C
0.1µ F
Optional: based upon the applications
Recording via AnaIn input
Notes:
* These capacitors may be needed in order to optimize for the best voice quality, which is also dependent
upon the layout of the PCB. Depending on system requirement, they can be 10 µF, 4.7 µF or other values.
Please refer to ChipCorder Applications section or consult Winbond for layout advice.
** For Sampling Freq at 8 kHz, R2 = 80 KΩ
*** It is important to have a separate path for each ground and power back to the related terminal to minimize
the noise. Also, the power supplies should be decoupled as close to the device as possible.
11.1 GOOD AUDIO DESIGN PRACTICES
To ensure the highest quality of voice reproduction, it is important to follow good audio design
practices in layout and power supply decoupling. See Application Information or links below for
details.
Good Audio Design Practices
http://www.winbond-usa.com/products/isd_products/chipcorder/applicationinfo/apin11.pdf
Single-Chip Board Layout Diagrams
http://www.winbond-usa.com/products/isd_products/chipcorder/applicationinfo/apin12.pdf
Confidential
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Publication Release Date: March 28, 2005
Revision A0