Rainbow Electronics ISD1600B - Manual (Page 7)

ISD1600B SERIES
Publication Release Date: Jan. 23, 2007
- 7 - Revision 1.2
5. PIN DESCRIPTION
SOIC / PDIP PIN NAME
PIN NO.
FUNCTIONS
V
SSD
1 Digital Ground : V
SSD
is the ground for digital circuits. It is
important to have a separate path for each ground back to
the system ground terminal to minimize noise.
REC
2
Record : The device starts recording whenever REC
transits from High to Low and stays at Low. Recording stops
when the signal returns to High. This pin has an internal
pull-up
resistor
[1] and an internal debounce on falling edge.
PLAYE
3 Edge-trigger Playback : A playback operation starts when
this input detects a low going signal exceeding the specified
debounced time. This pin has an internal pull-up
resistor
[1]
and an internal debounce on both falling & rising edge.
PLAYL
4 Level-trigger Playback : A playback operation begins when
this input detects a low going signal and remains at Low.
Playback stops when the signal returns to High. This pin has
an internal pull-up
resistor
[1] and an internal debounce on
falling edge.
V
SSA
5 Analog Ground : V
SSA
is the ground for analog circuits. It is
important to have a separate path for each ground back to
the system ground terminal to minimize noise.
MIC+ 6 Microphone Positive Input : The input transfers the signal
to the preamplifier. The internal Automatic Gain Control
(AGC) circuit controls the gain of the preamplifier. An
external microphone should be AC coupled to this pin via a
series capacitor. The capacitor value, together with an
internal 10 KΩ resistance on this pin, determines the low-
frequency cutoff for the ISD1600B passband.
MIC- 7 Microphone Negative Input : This is the inverting input to
the microphone preamplifier. It provides input noise-
cancellation, or common-mode rejection, when the
microphone is connected differentially to the device.
SP- 8 Speaker Negative : The SP-, Class D PWM output,
provides a differential output with SP+ pin to drive 8Ω
speaker or buzzer. During power down or recording, this pin
is tri-stated.
V
SSP
9 PWM Ground : V
SSP
is the ground for PWM speaker driver.
It is important to have a separate path for each ground back
to the system ground terminal to minimize noise.