ISD5116 WINBOND [Winbond], ISD5116 Datasheet - Page 25

• Manufacturer Part Number: ISD5116
• Description: Single-Chip Voice Record/Playback Device Up to 16-Minute Duration with Digital Storage Capability
• Manufacturer: WINBOND [Winbond]

4.6 ANA OUT DESCRIPTION
4.7 ANALOG INPUTS
4.7.1 Microphone Inputs
The microphone inputs transfer the voice signal to the on-chip AGC preamplifier or directly to the ANA
OUT MUX, depending on the selected path. The direct path to the ANA OUT MUX has a gain of 6 dB so
a 208 mV p-p signal across the differential microphone inputs would give 416 mV p-p across the ANA
OUT pins. The AGC circuit has a range of 45 dB in order to deliver a nominal 694 mV p-p into the storage
array from a typical electric microphone output of 2 to 20 mV p-p. The input impedance is typically 10kΩ.
The ACAP pin provides the capacitor connection for setting the parameters of the microphone AGC
circuit. It should have a 4.7 µF capacitor connected to ground. It cannot be left floating. This is because
the capacitor is also used in the playback mode for the AutoMute circuit. This circuit reduces the amount
of noise present in the output during quiet pauses. Tying this pin to ground gives maximum gain; to VCCA
gives minimum gain for the AGC amplifier but will cancel the AutoMute function.
October 2000
*DIFFERENTIAL PATH
AI G1
VLS1
15
15
VLS0
AI G0
14
14
*FTHRU
*INP
*VOL
*FILTO
*SUM1
*SUM2
MIC+
M I C –
ACAP
AIPD
VOL2
13
13
* Diffe re ntial Path
VOL1
AXG1 AXG0 AXPD
12
12
VOL0
11
11
3 (AOS2,AOS1,AOS0)
S1S1
10
10
AOS2
0
0
0
0
1
1
1
1
S1S0
I NS0
9
9
6 dB
AGC
AOS1
S1M1
AOS2 AOS1 AOS0 AOPD
0
0
1
1
0
0
1
1
8
8
1 ( AGPD)
To AutoMute
(Pl ayback Only)
S1M0 S2M1 S2M0
AOS0
7
7
0
1
0
1
0
1
0
1
*
6
6
MIC IN
FTHRU
AGC
SOURCE
FTHRU
FILTO
SUM1
SUM2
VOL
INP
N/C
N/C
5
5
(AOPD)
1
FLS0
OPS1
4
4
FLD1
OPS0 OPA1
3
3
AGPD
(1 Vp-p max. from AUX IN or ARRAY)
(694 mV p-p max. from mi crophone input)
0
1
FLD0
ANA OUT+
ANA OUT–
2
2
AOPD
CONDITION
Power Up
Power Down
0
1
FLPD
OPA0 VLPD
1
1
AGPD
CONDITION
Power Up
Power Down
0
0
Chip Set
CFG0
CFG1
Page 24