DAC7678: Maximum I2C clock speed

David Naviaux

Intellectual 590 points

Part Number: DAC7678

Tool/software:

From the datasheet, the DAC supports 3 I2C standards:

1. Standard Mode (100kHz)

2. Fast Mode (400kHz)

3. High-speed mode (3.4MHz)

Accidentally, I had configured my MCU's I2C clock speed for 1MHz and released a product several months ago. I was just reviewing the firmware associated with this DAC and I noticed that according to the datasheet, the maximum I2C clock speed is 400kHz. However, I never seemed to have a problem at 1MHz.

I was wondering if maybe the datasheet is not current and the DAC does actually support the "Fast Mode Plus" (1MHz)?

Thank you,

David

over 1 year ago

0 Erin Bowrie over 1 year ago

TI__Genius 10280 points

Hi David,

This isn't in the spec table, but the device does support Fast Mode+ with no special requirements. I'm not sure why they didn't add this to the I2C spec table. I'll put in a request to make an edit to the datasheet.

Thanks,
Erin

+1 Katlynne Jones over 1 year ago

TI__Mastermind 41903 points

Hi David,

Later in the datasheet the text does mention that the device supports fast mode+:

If you haven't experienced any issues then you can continue using your design as is. It looks like the fast mode+ wasn'tt explicitly stated because we don't meet the low level output current specified in the I2C bus standard, but this device can support the data speeds of fast mode +.

Best,

Katlynne Jones

0 David Naviaux over 1 year ago in reply to Katlynne Jones

Intellectual 590 points

Thank you Katlynee!

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DAC7678: Maximum I2C clock speed