TMP75: I2C access to TMP75A immediately, after Power-up?

Motoyasu Hattori

Genius 9695 points

Part Number: TMP75
Other Parts Discussed in Thread: TMP1075

Hi,

After Power-up, can MCU operate I2C access to TMP75A immediately?

If TMP75A needs some periods from power-up to accepting I2C access, could you please let us know the period?

Thanks and best regards,
M.HATTORI

over 2 years ago

+1 Eddie LaCost over 2 years ago

TI__Mastermind 40360 points

Hello Motoyasu,

We do not have the power up time specified in the datasheet of the TMP75A. The TMP75A is based on the TMP1075 device and this device does specify the reset time until an ADC conversion starts. See section 6.5 of the TMP75 datasheet.

https://www.ti.com/lit/ds/symlink/tmp1075.pdf

It is also important to note that the TMP75A will read 0 for the temperature until the first conversion is complete. Conversion times can be found in section 6.5 of the TMP75 datasheet.

Let me know if this is sufficient for your customer.

0 Motoyasu Hattori over 2 years ago in reply to Eddie LaCost

TI__Genius 9695 points

Eddie-san,

Thank you for your support. I have one additional question,

RESET time between reset till ADC conversion start is typical 0.3ms on the datasheet. My customer wants to know the worst case of this time, because he wants to define worst case of system start-up time. If difficult, could you please let us know whether this worst case is <1ms.?

Thanks and best regards,
M.HATTORI.

0 Eddie LaCost over 2 years ago in reply to Motoyasu Hattori

TI__Mastermind 40360 points

Hattori-san,

I am checking with the design team if we have a maximum specification available.

+1 Eddie LaCost over 2 years ago in reply to Eddie LaCost

TI__Mastermind 40360 points

Hattori-san,

The timing for the specification of time between reset till ADC conversion start can vary by up to 15%. Worst case is 0.35ms.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

Sensors

Sensors forum

TMP75: I2C access to TMP75A immediately, after Power-up?