ISD1700A Datasheet, PDF (9/31 Pages) Winbond – Multi-Message Single-Chip Voice Record&Playback Devices

ISD1700A SERIES
PIN NAME
V_SSP1
AUD
AGC
VOL
R_OSC
V_CCA
FT
PLAY
PDIP
PIN NO.
16
17
18
19
20
21
22
23
FUNCTIONS
Ground for Positive PWM Speaker Driver: It is important to have a
separate path for each ground signal including V_SSA, V_SSD, V_SSP1 and V_SSP2
to minimize the noise coupling.
Auxiliary Output: AUD is a single-ended current output. It can be used to
drive an external amplifier.
Automatic Gain Control (AGC): The AGC adjusts the gain of the
preamplifier dynamically to compensate for the wide range of microphone
input levels. The AGC allows the full range of signals to be recorded with
minimal distortion. The AGC is designed to operate with a nominal
capacitor of 4.7 µF connected to this pin.
Connecting this pin to ground (V_SSA) provides maximum gain to the
preamplifier circuitry. Conversely, connecting this pin to the power supply
(V_CCA) provides minimum gain to the preamplifier circuitry.
Volume Control: This control has 8 steps of volume adjustment. Each
Low pulse decreases the volume by one level. Repeated pulses decrease
the volume level from the current setting to the minimum then increase
back to the maximum, and continue this loop. The factory default is set at
maximum. This pin has an internal pull-up device ^[1] and an internal
debounce (T_Deb) ^[2] for start and end, allowing the use of a push button
switch.
Oscillator Resistor: A resistor connected from R_OSC pin to ground
determines the sample frequency of the device, which sets the duration.
Please refer to the Duration Section for details.
Analog Power Supply. It is important to have a separate path for each
power signal including V_CCD, V_CCA and V_CCP to minimize the noise
coupling. Decoupling capacitors to V_SSA should be as close to the device
as possible.
Feed-through: When FT is engaged Low, the AnaIn feed-through path is
activated. As a result, the AnaIn signal is transmitted directly from AnaIn
to both the Speaker and AUD outputs, via the volume control circuit. This
pin has an internal pull-up device ^[1] and an internal debounce (T_Deb) ^[2] for
start and end, allowing the use of a push button switch.
Playback: Pulsing PLAY to Low once initiates a playback operation.
Playback stops automatically when it reaches the end of the message.
Pulsing it to Low again during playback stops the operation.
Holding PLAY Low constantly functions as a sequential playback
operation loop. This looping continues until PLAY returns to High. This
pin has an internal pull-up device ^[1] and an internal debounce (T_Deb) ^[2] for
start and end, allowing the use of a push button switch.
Confidential
Publication Release Date: March 28, 2005
-9-
Revision A0