EMB1428Q: EMB1428 SPI Issue

Part Number: EMB1428Q

Hi,

We're developing EBM1428. But remove the EMB1499.

We have some SPI issue now.

Please check below picture.

This is our schematic:

We only modify MOSFET switch. And we made a EMB1428 only board for testing charge pump and SPI.

This is our SPI signal:

CH1(Yellow)=EMB1428 SDO

CH2(Blue)=MCU SDO

SPI/GPIO state information:

CLK:250KHz

CPL=LOW

CPHA=1Edge

Level:3.3V

Below picture show MCU send "0x70" to EMB1428.

GPIO

RST=5V(High)

DIR=float

DIR_RT=float

EN=float

DONE=float

Issue

EMB1428 doesn't output correct level and correct waveform.

BR,

Troy.Tsai