isd1740a Winbond Electronics Corp America, isd1740a Datasheet - Page 9

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

Confidential
PIN NAME
PLAY
V
AGC
AUD
R
V
VOL
FT
SSP1
OSC
CCA
PIN NO.
PDIP
16
17
18
19
20
21
22
23
Ground for Positive PWM Speaker Driver: It is important to have a
separate path for each ground signal including V
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
preamplifier circuitry. Conversely, connecting this pin to the power supply
(V
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
debounce (T
switch.
Oscillator Resistor: A resistor connected from R
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
coupling. Decoupling capacitors to V
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
start and end, allowing the use of a push button switch.
Playback: Pulsing
Playback stops automatically when it reaches the end of the message.
Pulsing it to Low again during playback stops the operation.
Holding
operation loop. This looping continues until
pin has an internal pull-up device
start and end, allowing the use of a push button switch.
CCA
) provides minimum gain to the preamplifier circuitry.
PLAY
Deb
)
Low constantly functions as a sequential playback
[2]
for start and end, allowing the use of a push button
PLAY
- 9 -
CCD
to Low once initiates a playback operation.
, V
FUNCTIONS
CCA
[1]
[1]
SSA
and an internal debounce (T
and an internal debounce (T
Publication Release Date: March 28, 2005
SSA
and V
) provides maximum gain to the
ISD1700A SERIES
should be as close to the device
CCP
PLAY
SSA
to minimize the noise
, V
returns to High. This
SSD
OSC
[1]
, V
and an internal
pin to ground
SSP1
and V
Revision A0
Deb
Deb
)
)
[2]
[2]
SSP2
for
for