User's Manual

Smart Machine Smart Decision
SIM7500A_User Manual_V1.00 2017-06-30
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Table 18: Pin multiplex function list
Note
： For more details of AT commands about GPIO multiplex function,please refer to
document [1].
3.11 Other interface
3.11.1 Sink Current Source
The ISINK pin is VBATtolerant and intended to drive some passive devices such as LCD backlight,
white LED, etc. Its output current can be up to 40 mA and be set by the AT command “AT+
CLEDITST”.
Table 19: Sink current electronic characteristic
Symbol Description Min. Typ. Max. Unit
V
ISINK
Voltage tolerant 0.5 - VBAT V
I
ISINK
Current tolerant 0 - 40 mA
ISINK is a ground-referenced current sink. The following figure shows its reference circuit.
Figure 26: ISINK reference circuit
Pin Number
Pin Name Default Function Alternate Function
4 SCL SCL GPIO11
5 SDA SDA GPIO10
12 USIM_DET GPIO34 USIM_DET
18 PCM_CLK PCM_CLK
GPIO23,SPI_CLK
I2C_SCL
19 PCM_SYNC PCM_SYNC GPIO20,SPI_MOSI
20 PCM_IN PCM_IN, GPIO21,SPI_MISO
21 PCM_OUT PCM_OUT
GPIO22,SPI_CS_N
I2C_SDA