ISD1810 Datasheet, PDF (5/18 Pages) Winbond – Single-Chip, Single-Message Voice Record/Playback Device 8- to 16-Second Durations

ISD1810 Product
A record cycle is completed when REC is pulled
LOW. An end-of-message (EOM) marker is internally
recorded, enabling a subsequent playback cycle
to terminate appropriately. The device automatical-
ly powers down to standby mode when REC goes
LOW. This pin has an internal pull-down device.
Holding this pin HIGH will increase standby current
consumption.
PLAYBACK, EDGE-ACTIVATED (PLAYE)
When a HIGH-going transition is detected on this
input pin, a playback cycle begins. Playback con-
tinues until an End-of-Message (EOM) marker is en-
countered or the end of the memory space is
reached. Upon completion of the playback cy-
cle, the device automatically powers down into
standby mode. Taking PLAYE LOW during a play-
back cycle will not terminate the current cycle.
This pin has an internal pull-down device. Holding
this pin HIGH will increase standby current con-
sumption.
preamplifier. An external microphone should be
AC coupled to this pin via a series capacitor. The
capacitor value, together with the internal 10 KΩ
resistance on this pin, determine the low-frequency
cutoff for the ISD1810 passband.
MICROPHONE REFERENCE (MIC REF)
The MIC REF input is the inverting input to the mi-
crophone preamplifier. This provides input noise-
cancellation, or common-mode rejection, when
the microphone is connected differentially to the
device.
Figure 1: ISD1810 Pinouts—For Sampling
Only
PLAYBACK, LEVEL-ACTIVATED (PLAYL)
When this input pin transitions from LOW to HIGH, a
playback cycle is initiated. Playback continues
until PLAYL is pulled LOW, an end-of-message
marker is detected, or the end of the memory
space is reached. The device automatically powers
down to standby mode upon completion of the
playback cycle. This pin has an internal pull-down
device. Holding this pin HIGH will increase standby
current consumption.
RECORD LED OUTPUT (RECLED)
The RECLED output is LOW during a record cycle.
It can be used to drive an LED to provide feed-
back that a record cycle is in progress. In addition,
RECLED pulses LOW momentarily when an end-of-
message or end-of-memory marker is encoun-
tered in a playback cycle.
MICROPHONE INPUT (MIC)
The microphone input transfers its signal to the on-
chip preamplifier. An on-chip Automatic Gain
Control (AGC) circuit controls the gain of the
NOTE: NC means must Not Connect.
AUTOMATIC GAIN CONTROL (AGC)
The AGC dynamically adjusts the gain of the
preamplifier to compensate for the wide range of
microphone input levels. The AGC allows the full
range of sound, from whispers to loud sounds, to
be recorded with minimal distortion. Nominal val-
ues of 4.7 µF give satisfactory results in most cas-
es.
2
Voice Solutions in Silicon^™