TMP112: SDA logic high voltage level is wrong

Raghuveer Kasaraneni

Part Number: TMP112

TMP112AIDRLR is connected to an I2C bus along with other I2C slaves. The design is same as Figure 17 of datasheet (SBOS473H–MARCH 2009–REVISED OCTOBER 2018). The filtering resistance is also added as per Figure 18. All the other slaves on I2C bus are functioning properly. But the SDA logical high voltage level is lower than expected when TMP112 is transmitting. The situation didn't change when a pull-up resistor of 1.6kohms is used on SDA. Voltage at V+ is 3.3V.

over 5 years ago

0 Amit Ashara over 5 years ago

TI__Guru**** 244380 points

Hello Raghuveer

Looking at the SDA line, it seems there is a current draw happening which is causing the line to be lower than the expected 3.3V due to pull up

Step-1: Replace the TMP112 to see if it is a faulty device
Step-2: Remove the other I2C bus to ensure it is TMP112 causing the behavior

Let us know what you find after following the steps 1-2 above.

0 Raghuveer Kasaraneni over 5 years ago in reply to Amit Ashara

Prodigy 140 points

Hello Amit,
The problem is that there is another slave with same I2C address. Thank you for your reply.

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TMP112: SDA logic high voltage level is wrong