LP3943: I2C_DATA read/write data mismatch

Jamie Tseng

Part Number: LP3943

Hi team,

My customer is facing the writing value and the reading value of LP3943 are not match.

**Write**

Write I2C address : 0x61 (1 1 0 0 0 0 1 W)

Write LP3943 address : 0x06 (0 0 0 0 0 1 1 0)

Write LP3943 value : 0x04 ( 0 0 0 0 0 1 0 0)

**Read**

Read I2C address : 0x61 (1 1 0 0 0 0 1 W)

Read LP3943 address : 0x06 (0 0 0 0 0 1 1 0)

Read LP3943 value : 0Xff (1 1 1 1 1 1 1 1)

Could you kindly help with this case?

Thanks and best regards,

Jamie

over 5 years ago

0 Charles-Chen over 5 years ago

Hi Jamie,

If a READ function is to be accomplished, a WRITE function must precede the READ function, as shown in Figure6 in datasheet.

0 Jamie Tseng over 5 years ago in reply to Charles-Chen

Hi Charles,

In the previous post, the customer measured the waveforms of write & read at the same time.

And the waveforms on the oscilloscope all meet the requirements of the datasheet, just grab the pictures separately to confirm the bits.

Is there anything that can cause the read/write data mismatch?

Thanks and best regards,

Jamie

0 Charles-Chen over 5 years ago in reply to Jamie Tseng

Hi,

Can customer test it together in the same waveform?

0 Charles-Chen over 5 years ago in reply to Jamie Tseng

Hi Jamie,

It seems that the time between read and write is too long.

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