SimCom SIM800L Hardware Design page 16

VDD_EXT 18
2,6,8,35,37,38,39,
41,43,44,45,58,67
GND ,71,72,73,76,77,7
8,79,80,81,82,83,
84,85,86,87,88
Power on/down
PWRKEY 48
Audio interfaces
MIC1P 52
MIC1N 12
SPK1P 53
SPK1N 13
MIC2P 9
MIC2N 10
SPK2P 51
SPK2N 11
PCM interface
PCM_CLK 29
PCM_OUT 30
PCM_SYNC 65
PCM_IN 66
Keypads interface
KBC4 24
KBC3 21
KBC2 22
KBC1 25
KBC0 20
KBR4 63
KBR3 23
KBR2 61
KBR1 60
KBR0 62
GPIO
GPIO1 3
GPIO2 27
GPIO3 28
SIM800L(MT6261)_Hardware Design_V1.01
O 2.8V power output
Ground
PWRKEY should be pulled low at
I least 1 second and then released to
power on/down the module.
I Differential audio input
O Differential audio output
I Differential audio input
O Differential audio output
O
O
PCM interface for digital audio
O
I
I
I
I
I
I
Support up to 50 buttons (5*5*2)
O
O
O
O
O
I/O
Programmable general purpose input
I/O
and output
I/O
Smart Machine Smart Decision
capacitor (e.g. 4.7uF).
If these pins are unused,
keep open.
GND for VBAT recommend
to use 2,43,44,45pin
Internally
VBAT.
If these pins are unused,
keep open.
If these pins are unused,
keep open.
If these pins are unused,
keep open.（Please make
sure pin20 at high level
when power on）
16
pulled up to
2016-07-07