TMP175: Low temperature test

Kung Poyuan

Part Number: TMP175
Other Parts Discussed in Thread: TMP117, TMP1075

Tool/software:

HI TI Teams

As shown in the attached image, the IIC communication waveform (400 K) of the TMP175 at room temperature, with both SDA and SCL rise times being less than 300ns.

During a week-long low-temperature (-40°C) stress test, there was one instance of IIC lock-up (SDA Force 0).

Do you have any recommended solutions for this issue?

8 months ago

0 Ren Schackmann 8 months ago

TI__Mastermind 43785 points

Please see the following post regarding TMP117 as it also pertains to your question.

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1452081/tmp117-crashing-the-i2c-bus-when-temperature-rises/5571895#5571895

TMP175 also has the SMBus Timeout feature that causes it to release SDA in the event a transaction is corrupted or stalled. It wouldn't be possible for TMP175 to hold SDA low indefinitely. I2C does not have the timeout feature in its specification, so a strict I2C device on the same bus could behave this way. It's recommended to send 9 clocks to clear the I2C bus under this condition.

thanks,

ren

0 Kung Poyuan 8 months ago in reply to Ren Schackmann

Prodigy 241 points

Would the TMP1075 have the same issue?

0 Ren Schackmann 8 months ago in reply to Kung Poyuan

TI__Mastermind 43785 points

TMP1075 and TMP117 both have the SMBus Timeout feature which prevents SDA lock up.

ren

0 Kung Poyuan 8 months ago in reply to Ren Schackmann

Prodigy 241 points

Currently, access is through LINUX IIC. Is it possible to enable the Timeout feature to prevent SDA lock?

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TMP175: Low temperature test