¡ Semiconductor
MSM7715
Name Pin No. I/O
Description
VDD
29
— Power supply. Supply +2.5V to 3.6V.
AIN
31
I Input for the analog receiving signal.
SGO
32
O
Output for the signal ground voltage. The output voltage is 1/2 VDD.
Connect a capacitor of 0.1 mF or more between SGO and GND.
SGC
GAT1
GAT2
MOD
DTO
34
—
Pin for connecting the capacitor of the signal ground voltage generating circuit.
Connect a capacitor of 1 mF or more between SGC and GND.
35
I Input for the sending output level-adjusting amplifier.
36
O Output for the sending output level-adjusting amplifier.
37
O Output for the sending modem signal.
38
O Output for the DTMF signal.
VR1
VR2
GND
DTG1
DTG2
DTG3
39
O
Output for the reference voltage generating circuit.
The potential difference between VR1 and SGO is approximately +0.75 V.
40
I Input for external adjustment of the modem’s carrier detection level.
41
— Ground.
42
Inputs for specifying the DTMF code to be sent.
43
I* Data is latched at the falling edge of TEN.
44
Note: Digital inputs that are pulled up internally by a high resistance.
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