isd1740a Winbond Electronics Corp America, isd1740a Datasheet - Page 26

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

11 TYPICAL APPLICATION CIRCUITS
Two example circuits illustrate recording via MIC and AnaIn inputs, respectively. These examples
show typical implementations of ISD1740A/50A/60A devices. .
Example #1:
Notes:
*
**
***
**
Sample Freq [kHz]: 12 8 6.4 4
Rosc [K ]
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 requirements, they can be 10 PF, 4.7 PF or other values.
Please refer to the ChipCorder Applications section or consult Winbond for layout advice.
For Sampling Freq at 8 kHz, Rosc = 80 K:
It is important to have a separate path for each ground and power back to each terminal to minimize the
noise. Also, the power supplies should be decoupled as close to the device as possible
:
60 80 100 160
V
CC
4.7 K :
4.7 K
4.7 K :
:
0.1 F
Rosc **
0.1 F
4.7 F
Vcc
P
P
P
4.7 F
P
Recording via MIC input
24
23
25
26
19
22
10
11
3
7
6
5
4
20
18
9
REC
PLAY
ERASE
RESET
FT
ANA IN
R
AGC
FWD
TE3
TE2
TE1
NC
MIC -
MIC+
VOL
OSC
ISD1740A
ISD1750A
ISD1760A
- 26 -
V
V
SP-
AUD
RDY
V
SP+
V
V
V
LED
V
SSP1
SSP2
CCA
SSA
CCP
CCD
SSD
28
21
14
16
12
15
13
17
27
2
1
8
1 K:
0.1 F
0.1 F
ISD1700A SERIES
P
P
V
CCP
Optional: based upon the applications
D1
V
CCD
or Buzzer
*
Speaker
0.1 F
vAlert
0.1 F
P
*
P
390 :
V
R6
CC
V
CCA
Speaker
.
*
***
V
V
*
V
0.1 F
CCA
CCD
CCP
C5
V
P
CC
8050C
Q1
***