Rainbow Electronics APR6008 - Manual (Page 15)

APR6008
Voice Recording & Playback Device Page 15
Revision 2.1
Sample Application
Figure 15 shows a sample application utilizing a generic
microcontroller and SPI interface for message management.
The microcontroller uses three general purpose inputs for the
play, record and skip buttons. Five general purpose I/O sig-
nals are utilized in the SPI interface. The /RESET and /BUSY
signal are not used in this design.
The output signal must be amplified in order to drive a
speaker. Several vendors supply integrated speaker amplifi-
ers that can be used for this purpose.
A microphone amplifier and AGC are recommended. Both
blocks are optional. Several vendors supply integrated micro-
phone/AGC amplifiers that can be used for this purpose.
Note that the AGC circuit can be simplified by using the SQLCAP signal as a
peak detector signal.
Figure 15 Sample Schematic using DIP package
All resistors 2.2 K
/C S
D I
D O
V S SD
N C
N C
N C
A N AO U T-
AN A O U T +
N C
/R ES E T
VS SA
A U D O U T
S Q LC AP
S C LK
V C C D
E XT C LK
/IN T
S AC
V SS A
N C
/BU S Y
N C
N C
V C C A
A N AIN +
A N AIN -
/SQ L O U T 28
27
26
25
24
23
22
21
20
19
18
17
16
15 1
2
3
4
5
6
7
8
9
10
11
12
13
14
G eneric
M icrocontroller
I/O_4
I/O_5
I/O _7
I/O _8
I/O _6
0 .1 µ F
1 0 0 K
V c c
/IR Q
I/O_3
I/O_2
I/O _1 Play
Record
Skip
Vcc
1 .0 u F
V cc
Speaker
APR6008 DIP
AG C
Block
S p e a k e r
A m p lifie r
Vcc
Mic
Pre-Amp
M ic
Vcc
2.2K 2.2K