54 ms

26 ms

26 ms

Startup

Start of

Conversion

Figure 4. Conversion Diagram

Functional Modes

Continuous Mode

The default mode of the TMP75 is continuous conversion, where the ADC performs continuous temperature

conversions and stores each result to the Temperature register, overwriting the result from the previous conversion.

The typical conversion rate of TMP75 is 12 Hz, with 80 ms between the start of each consecutive conversion. The

TMP75 has a typical conversion time of 26 ms. To achieve its conversion rates, the TMP75 makes a conversion, and

then powers down and waits for a delay 54 ms.

After power-up, the TMP75 immediately starts a conversion, as shown in Figure 4. The first result is available

after 26 ms (typical). The active quiescent current during conversion is 40 μA (typical at +25°C). The quiescent current

during delay is 2.2 μA (typical at +25°C).

Shutdown Mode

The shutdown mode saves maximum power by shutting down all device circuitry other than the serial interface,

and reduces current consumption to typically less than 0.5 μA. Shutdown mode is enabled when the SD bit in the

configuration register is set to 1; the device shuts down and terminates a conversion if it is ongoing. When SD is

equal to 0, the device operates in continuous-conversion mode. When shutdown mode is enabled, the ALERT pin

and fault counter clear in both comparator and interrupt modes. The ALERT pin and the fault counter remain clear

until the SD bit is set.

One-Shot Mode

The TMP75 features a one-shot temperature measurement mode. When the device is in continuous conversion

(SD = 0), writing a 1 to the OS bit enables shutdown mode, where any write to the one-shot register triggers a single

temperature conversion. The device returns to the shutdown state at the completion of the single conversion, and a

subsequent write to the one-shot register triggers another single conversion followed by a return to shutdown state.

This mode reduces power consumption in the TMP75 when continuous temperature monitoring is not required.

When the device is in complete shutdown (SD = 1), the one-shot mode is not active regardless of the state of

the OS bit, and a write to the one-shot register has no effect.

UMW R

www.umw-ic.com

9

UTD Semiconductor Co.,Limited

TMP75

1.8V Digital Temperature Sensor with I 2C Interface and Alarm Function

UMW R