isd1800 Winbond Electronics Corp America, isd1800 Datasheet - Page 11

• Manufacturer Part Number: isd1800
• Description: Single-chip, Single-message Voice Record/playback Device 6- To 16-second Duration
• Manufacturer: Winbond Electronics Corp America

ISD1800 SERIES
8. RECLED operation
The RECLED output pin provides an active-LOW signal, which can be used to drive an LED as a
“record-in-progress” indicator. It returns to a HIGH state when the REC pin is released LOW or when
the recording is completed due to the memory being filled. This pin also pulses LOW to indicate the
end of a message has been reached.
9. ROSC operation
The duration of the device can be varied by changing the value of R2 (R
). This means the
ISD1800
OSC
device can actually be between 6 to 16 seconds duration. See the curve below, which charts typical
durations when the R
is varied from 80 KΩ to 160 KΩ.
OSC
This feature allows frequency shifting where a recorded voice or sound can be played back faster or
slower than normal for special effects. For example, use a 100 KΩ resistor to make the recording and
then playback with either an 80 KΩ resistor for faster “chipmunk” talk or with a 120 KΩ resistor for a
slower, lower voice.
Another feature is a “Pause” or interrupt function that can be done by taking the R
resistor to V
to
OSC
CC
stop playback momentarily, resuming when the resistor is connected back to ground.
Chart 1: ISD Duration Versus R
at T
= 25°C and V
= 3.0V
OSC
A
CC
80
100
120
140
160
Ω
Typical R
(K
)
OSC
Publication Release Date: June 7, 2005
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Revision 0.3