About resister writing of LDC1000

Satoshi

Guru 19485 points

When resister writing to LDC1000, nothing is sometimes written in.

Can some cause think of?

I think there is timing until begin to write after a power supply is turned on.

When it's right, please tell me the this time.

------------------------------------------------------------------------------------

【Additional information】

・PWR_mode is "Stand by". (No problem)

・Customer don't use CSB pin. (Controlling one LDC1000)

・Procedure

　・Power supply on

　　↓

　・Initialization

　　　(1) RpMAX (0x01)

　　　(2) RpMIN (0x02)

　　　(3) Min Resonating Frequency (0x03)

　　　(4) Amplitude & Response Time (0x04)

　　　(5) PWR_Mode：Active mode set (0x08)

------------------------------------------------------------------------------------

Best regards,

Satoshi

over 9 years ago

0 Chris Oberhauser66 over 9 years ago

TI__Genius 14270 points

Hi Satoshi,

The CSB signal is necessary to set registers.

Regards,

ChrisO

0 Daniel Schmidt over 9 years ago

Prodigy 70 points

Just to make sure, you are not applying CSB at all? Is it continuously low?

As far as I understand you need to use the CSB to make the LDC work properly.

"It is required to deassert CSB after the 16th clock; if CSB is deasserted before the 16th clock, no data write will occur." Quote form the Manual (SPI Description)

Your working scenario seem to initiate the Extended SPI transactions.

0 Natallia Holubeva1 over 9 years ago in reply to Daniel Schmidt

TI__Expert 6550 points

Daniel,

You are correct. Thank you for your help.

Best Regards,

Natallia Holubeva

0 Satoshi over 9 years ago in reply to Natallia Holubeva1

Guru 19485 points

Dear All

Thank you for advice.

I got waveform data, please see attach.

※CS is CSB-pin.

The waveform of writing in NG is same as writing in OK.

When a power supply is turned off and it's turned on immediately, it can write(OK).

I think that a writing signal is sent before LDC normally moves.

(Is the one of the function of the CPU early?)

Is there time until LDC normally moves after a power supply is turned on?

(If VIO will be 1.8V(MIN), immediately, is it possible to start?)

Best regards,

Satoshi

0 Natallia Holubeva1 over 9 years ago in reply to Satoshi

TI__Expert 6550 points

Hello Satoshi,

The minimum analog voltage supply for the part to start is 4.75V. The SPI timing diagram is described below:

Best Regards,

Natallia Holubeva

Sensors

Sensors forum

About resister writing of LDC1000