Smart Machine Smart Decision
SIM800_Hardware Design_V1.10
15
2018-08-13
3.2.
Pin Description
Table 4: Pin description
Pin name
Pin
number
I/O
Description
Comment
Power supply
VBAT
55,56,57
I
SIM800 supplies 3 VBAT pins, and
the power range is from 3.4V to 4.4V.
Power supply should provide
sufficient current so that the module
can work normally; the peak current
is nearly 2A.
Zener diode is Strongly
recommended to anti surge
on VBAT.
VRTC
26
I/O
Power supply for RTC
It is recommended to
connect VRTC to a battery
or a capacitor (e.g. 4.7uF).
VDD_EXT
15
O
2.8V power output
Keep floating if unused.
GND
2,17,18,29,3
9,45,46,54,5
8,59,61,62,6
3,64,65
Ground
GND for VBAT
recommend to use 62, 63,
64, 65 pin
.
Power on/off
PWRKEY
1
I
PWRKEY should be pulled low at
least 1.2 second and then released to
power on/down the module.
Internally pulled up to
VBAT.
Audio interface
MICP
19
I
Differential audio input
Keep floating if unused.
MICN
20
SPKP
21
O
Differential audio output
SPKN
22
PCM interface
PCM_OUT
6
O
PCM interface for audio
Keep floating if unused.
PCM_IN
12
I
PCM_SYNC
14
O
PCM_CLK
68
I
Keypad interface
KBC4
47
I
Support up to 50 buttons (5*5*2)
Keep floating if unused.
(KBC0 can not be pulled
down).
KBC3
48
I
KBC2
49
I
KBC1
50
I
KBC0
51
I
KBR4
40
O
