Figure 6. Internal Register Structure

registers to the power-up reset values, and aborts the current temperature conversion. If the second byte is other

value, the TMP175 will not respond.

High-Speed Mode

For the two-wire bus to operate at frequencies above 400kHz, the host device must issue a High-Speed mode

host code (0000 1xxxb) as the first byte after a START condition to switch the bus to high-speed operation. The

TMP175 device does not acknowledge this byte, but it does switch the input filters on the SDA and SCL and the

output filters on the SDA to operate in High-Speed mode, allowing the bus to transmit data at frequencies up to

2.75MHz. After the High-Speed mode host code is issued, the host transmits a two-wire device address to initiate a

data transfer operation. The bus continues to operate in High-Speed mode until a STOP condition occurs on

the bus. Upon receiving the STOP condition, the TMP175 switches the input and output filters back to fast-mode

operation.

Time-Out Function

The TMP175 resets the serial interface if SCL is held low for 30ms (typical value) between a START and

STOP condition, the TMP175 releases the SDA bus and waits for a START condition. To avoid activating the

Time-Out function, a communication speed of at least 1kHz must be maintained.

Register Descriptions

Pointer Register

Figure 6 shows the internal register structure of the TMP175 device. The 8-bit Pointer Register of the device is

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Low-Power, LM75-Compatible Digital Temperature Sensor WithSMBus and I 2C Interface

TMP175

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