ISD5116 WINBOND [Winbond], ISD5116 Datasheet - Page 34

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

6.2 ANALOG I/O PINS
MIC+, MIC- (Microphone Input +/-)
The microphone input transfers 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 electret microphone output of 2 to 20 mV p-p. The input impedance is typically 10 k .
ANA OUT+, ANA OUT- (Analog Output +/-)
This differential output is designed to go to the microphone input of the telephone chip set. It is designed
to drive a minimum of 5 k
pins have DC bias of approximately 1.2 VDC. The AC signal is superimposed upon this analog ground
voltage. These pins can be used single-ended, getting only half the voltage. Do NOT ground the unused
pin.
ACAP (AGC Capacitor)
This 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; tying it to
V
SP +, SP- (Speaker +/-)
This is the speaker differential output circuit. It is designed to drive an 8
speaker pins up to a maximum of 23.5 mW RMS power. This stage has two selectable gains, 1.32 and
1.6, which can be chosen through the configuration registers. These pins are biased to approximately 1.2
VDC and, if used single-ended, must be capacitively coupled to their load. Do NOT ground the unused
pin.
October 2000
CCA
gives minimum gain for the AGC amplifier but cancels the AutoMute function.
220 F
Microphone
Panasonic
WM-54B
Electret
+
VCC
between the “+” and “–” pins to a nominal voltage level of 700 mV p-p. Both
1.5k
1.5k
1.5k
C
COUP
0.1 F
=0.1 F
MIC+
MIC-
Ra=10k
10k
Internal to the device
NOTE: f
6 dB
AGC
CUTOFF
=
FTHRU
MIC IN
speaker connected across the
2 RaC
1
COUP
Page 33