ISD3900
Publication Release Date: Dec 10, 2013
- 10 -
Revision 1.5
Pin
Number
Pin Name
I/O
Function
18
SPK+
O
PWM driver positive output. This SPK+ output, together with SPK- pin,
provide a differential output to drive 8
Ω speaker or buzzer. During
power down this pin is in tri-state.
Or, can be configured as BTL which, together with SPK- pin, provide a
differential voltage output.
Or, can independently switch to AUDOUT or AUXOUT.
19
V
SSD
_PWM
I
Digital Ground for the PWM Driver.
20
SPK-
O
PWM driver negative output. This SPK- output, together with SPK+
pin, provides a differential output to drive 8
Ω speaker or buzzer.
During power down this pin is tri-state.
Or, can be configured as BTL which, together with SPK+ pin, provide a
differential voltage output.
Or, can independently switch to AUDOUT or AUXOUT.
21
V
CCD
_PWM
I
Digital Power for the PWM Driver.
22
NC
This pin should be left unconnected.
23
NC
This pin should be left unconnected.
24
NC
This pin should be left unconnected.
25
INTB
O
Active low interrupt request pin. This pin is an open-drain output.
26
RDY/BSYB
O
An output pin to report the status of data transfer on the SPI interface.
“High” indicates that ISD3900 is ready to accept new SPI commands
or data.
27
RESET
I
Applying power to this pin will reset the chip. (A high pulse of 50ms or
more will reset the chip.)
28
DO
O
Serial data output of the external serial flash interface. Connects to
data input (DI) of external serial flash.
29
CLK
O
Serial data CLK of the external serial flash interface.
30
GPIO3
I/O
GPIO
31
GPIO2
I/O
GPIO
32
GPIO1
I/O
GPIO
33
NC
This pin should be left unconnected.
34
NC
This pin should be left unconnected.
35
XTALOUT
O
Crystal interface output pin.