ISD2500 ETC1 [List of Unclassifed Manufacturers], ISD2500 Datasheet - Page 23

• Manufacturer Part Number: ISD2500
• Description: Single-Chip Voice Record/Playback Devices 32-, 40-, 48-, 64-,60-,75,90-, and 120-Second Durations
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

Product Data Sheets
APPLICATION EXAMPLE – PASSIVE COMPONENT FUNCTIONS
EXPLANATION
In this simplified block diagram of a microcontroller
application, the Push-Button mode and message
cueing are used. The microcontroller is a 16-pin
version with enough port pins for buttons, an LED,
and the ISD2500 Series device. The software can
be written to use three buttons: one each for play
and record, and one for message selection.
Because the microcontroller is interpreting the but-
tons and commanding the ISD2500 device,
software can be written for any functions desired in
a particular application.
R1
R2
R3, R5
R4
R6
C1, C5
C2
C3
C4
C6, C7, C8
Part
Microphone power supply
decoupling
Release time constant
Microphone biasing resistors
Series limiting resistor
Series limiting resistor
Microphone DC–blocking capacitor
Low-frequency cutoff
Attack/Release time constant
Low-frequency cutoff capacitor
Microphone power supply
decoupling
Power supply capacitors
Function
Reduces power supply noise
Sets release time for AGC
Provides biasing for microphone operation
Reduces level to prevent distortion at higher supply
voltages.
Reduces level to high supply voltages
Decouples microphone bias from chip. Provides single-
pole low-frequency cutoff and common mode noise
rejection.
Sets attack/release time for AGC
Provides additional pole for low-frequency cutoff
Reduces power supply noise
Filter and bypass of power supply
NOTE
*
Advance information: ISD2532/40/48/64 devices.
ISD does not recomend connecting
address lines directly to a microprocessor
bus. Address lines should be externally
latched.
Comments
ISD2500 Series
1–101
1