TMP117 datasheet(34/45 Pages) TI1

34 / 45 page

TMP117

SNOSD82 – JUNE 2018

www.ti.com

Product Folder Links: TMP117

Submit Documentation Feedback

Application Information (continued)

The following methods can reduce the SHE:

•

System calibration removes not only the self-heating error and power-supply rejection ratio (PSRR) effect but

also compensates the temperature shift caused by the thermal resistance between the device and the

measured object.

•

If practical, use the device one-shot mode. If continuous conversion is needed, use the conversion cycle

mode with significant standby time. For example, in most cases an 8-sample averaging (125 ms) with a 1-

second conversion cycle provides enough time for the device to cool down to the environment temperature

and removes the SHE.

•

Use the minimal acceptable power supply voltage.

•

Use a printed-circuit board (PCB) layout that provides minimal thermal resistance to the device.

•

Avoid using small-value pullup resistors on the SDA and ALERT pins. Instead, use pullup resistors larger than

2 kΩ.

•

Ensure that the SCL and SDA signal levels remain below 10% or above 90% of the device supply voltage.

•

Avoid heavy bypass traffic on the data line. Communication to other devices on the same data line increases

the supply current even if the device is in SD mode.

•

Use the highest available communication speed.

8.1.1.2.4

Synchronized Temperature Measurements

When four temperature measurements are needed in four different places simultaneously, triggering a reset is

recommended. In this method, four devices are programed with control registers set to CC mode with a

conversion cycle time of 16 s. All four devices are connected to same two-wire bus with four different bus

addresses. The bus general-call reset command is issued by the master. This command triggers all devices to

reset (which takes approximately 1.5 ms) and triggers a simultaneous temperature sampling according to

configuration registers setting. The master has 16 seconds to read data from the devices.

TMP117 Datasheet(PDF) 34 Page - Texas Instruments