EMB1428Q: EMB1428 SPI Issue

Troy.Tsai

Intellectual 365 points

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

over 6 years ago

0 Taylor Vogt over 6 years ago

TI__Genius 17370 points

Hi Troy.Tsai,

Can you please check if your issue is related/similar to this other thread below (specifically about the reset pin at the bottom)?:

https://e2e.ti.com/support/power-management/f/196/t/817275

Let me know what you find.

Regards,

Taylor

0 Troy.Tsai over 6 years ago in reply to Taylor Vogt

Intellectual 365 points

Hi Taylor,

Thank you for your replying.

Sorry not clear in my original post.Let me clarify.

I have two issue now.

1.SPI doesn't return data and level is wrong. The level should be reach 3.4V(VDDIO=5V)

2.CEXT1 and CEXT2 both has no 1MHz waveform output.

But still thank you for you provide related post!

Let me try to control RESET pin by MCU 3.3V GPIO.

And I have one more question about EVM and datasheet.

Datasheet shows charge pump need "0.01uF" capacitor, but on the EVM is "0.1uF". Please let me know which is right.

BR,

Troy

0 Troy.Tsai over 6 years ago in reply to Troy.Tsai

Intellectual 365 points

Hi Taylor,

Just solved SPI issue. Thank you for your response.

Wrong sequence:

RST always HIGH

1.CS set to LOW

2.SPI send data to EMB1428

3.CS set to HIGH

Correct sequence:

1.RST set to LOW

2.CS set to LOW

3.SPI send data to EMB1428

4.CS set to HIGH

5.RST set to HIGH

BR,

Troy

0 Troy.Tsai over 6 years ago in reply to Taylor Vogt

Intellectual 365 points

Hi Taylor,

SPI is working fine now. But CEXT1, CEXT2 still has no output square waveform.

I've check the block diagram, it should work when VDD5V, VDDP is correct.

Do you have any idea about this? I've put every charge pump component on it.

BR,

Troy

0 Taylor Vogt over 6 years ago in reply to Troy.Tsai

TI__Genius 17370 points

Hi Troy,

I do not know exactly what may be going on, can you provide more waveforms/details in a new thread? I will close this thread as it has been resolved so it is easy to miss a follow up question.

Thanks,

Taylor

0 Troy.Tsai over 6 years ago in reply to Taylor Vogt

Intellectual 365 points

Hi Taylor,

Understand. I'll create new thread. Thank you for your helping.

BR,

Troy

Power management

Power management forum

EMB1428Q: EMB1428 SPI Issue

SPI/GPIO state information:

GPIO

Issue