Specifications

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5. Reference Design
5.1. UART Interface Design
For devices with 3.3V power supply, you can directly connect the device UART port with
module UART port according to the illustration in Fig 12.
Fig 12 Circuit diagram (3.3V)
If your device is powered by 5V, you can refer to the circuit shown in Fig 13 or design your
own circuit for power conversion. The value of resistor can be adjusted according to actual circuit
design.
5.2. Power Supply Requirement
If an LDO is used to supply the module with 3.3V power, C1 capacitor can be considered to
be used with 10u-22u; If a DCDC is used to supply 3.3V power, C1 capacitor can be considered to
be used with 22uF.
It is recommended to supply the module with power higher than 400mA to ensure enough
power supply to the module and avoid power down during data transmission.