Spi Interface - Quectel EG91 Series Hardware Design

3.13. SPI Interface

SPI interface of EG91 series module works as the master only. It provides a duplex, synchronous and
serial communication link with the peripheral devices. It is dedicated to one-to-one connection, without
chip selection. Its operation voltage is 1.8 V with clock rates up to 50 MHz.
The following table shows the pin definition of SPI interface.
Table 14: Pin Definition of SPI Interface
Pin Name Pin No.
SPI_CLK 26
SPI_MOSI 27
SPI_MISO 28
The following figure shows a reference design of SPI interface with peripherals.
Figure 25: Reference Circuit of SPI Interface with Peripherals
NOTE
EG91 series provides 1.8 V SPI interface. A voltage-level translator should be used between the module
and the host if your application is equipped with a 3.3 V processor or device interface.
EG91_Series_Hardware_Design
I/O Description
DO SPI clock
DO SPI master-out slave-in
DI SPI master-in slave-out
LTE Standard Module Series
Comment
1.8 V power domain.
If unused, keep it open.
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