isd1740a Winbond Electronics Corp America, isd1740a Datasheet - Page 8

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

5 PIN DESCRIPTION
PIN NAME
RESET
AnaIn
MIC+
V
MIC-
V
LED
V
V
TE1
TE2
TE3
SP+
SP-
NC
SSP2
CCD
CCP
SSA
PIN NO.
PDIP
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
Digital Power Supply: It is important to have a separate path for each
power signal including V
coupling. Decoupling capacitors should be as close to the device as
possible.
LED: This output turns on a LED during a record cycle and blinks LED
during playback, forward and erase operations.
RESET: When Low, the device enters into a known state and initializes all
pointers to the default state. This pin has an internal pull-up resistor
NC: No Connect.
Test pin #1: Connect to V
Test pin #2: Connect to V
Test pin #3: Connect to V
Analog Ground: It is important to have a separate path for each ground
signal including V
coupling.
AnaIn: Auxiliary analog input to the device for recording or feed-through.
An AC-coupling capacitor (typical 0.1uF) is necessary and the amplitude
of the input signal should not exceed 1.0 Vpp.
MIC+: Non-inverting input of the differential microphone signal. The input
signal should be AC-coupled to this pin via a series capacitor. The
capacitor value, together with an internal 10 KŸ resistance on this pin,
determines the low-frequency cutoff for the pass band filter.
MIC-: Inverting input of the differential microphone signal. The input signal
should be AC-coupled to the MIC+ pin. It provides input noise-
cancellation, or common-mode rejection, when the microphone is
connected differentially to the device.
Ground for Negative PWM Speaker Driver: It is important to have a
separate path for each ground signal including V
to minimize the noise coupling.
SP-: The negative Class D PWM provides a differential output with SP+
pin to directly drive an 8 speaker or typical buzzer. During power down
or recording, this pin is tri-stated.
Power Supply for PWM Speaker Driver: It is important to have a
separate path for each power signal including V
minimize the noise coupling. Decoupling capacitors to V
should be as close to the device as possible. The V
ground pins have large transient currents and need low impedance
returns to the system supply and ground, respectively.
SP+: The positive Class D PWM provides a differential output with the
SP- pin to directly drive an 8 speaker or typical buzzer. During power
down or recording, this pin is tri-stated.
SSA
- 8 -
, V
SSD
CCD
CCD
CCD
CCD
, V
.
.
.
, V
FUNCTIONS
SSP1
CCA
and V
and V
ISD1700A SERIES
SSP2
CCP
SSA
to minimize the noise
to minimize the noise
CCD
, V
CCP
, V
SSD
, V
CCA
supply and V
SSP1
SSP1
and V
and V
and V
[1]
CCP
.
SSP2
SSP2
SSP
to