General description

The PCT2075 is a temperature-to-digital converter featuring ±1 °C accuracy over -25 °C to +100 °C range. It uses an on-chip band gap temperature sensor and Sigma-Delta A-to-D conversion technique with an overtemperature detection output that is a drop-in replacement for other LM75 series thermal sensors. The device contains a number of data registers: Configuration register (Conf) to store the device settings such as device operation mode, OS operation mode, OS polarity and OS fault queue; temperature register (Temp) to store the digital temp reading, set-point registers (Tos and Thyst) to store programmable overtemperature shutdown and hysteresis limits, and programmable temperature sensor sampling time Tidle, that can be communicated by a controller via the 2-wire serial I2C-bus Fast-mode Plus interface.

The PCT2075 also includes an open-drain output (OS) which becomes active when the temperature exceeds the programmed limits. The OS output operates in either of two selectable modes: OS comparator mode or OS interrupt mode. Its active state can be selected as either HIGH or LOW. The fault queue that defines the number of consecutive faults in order to activate the OS output is programmable as well as the set-point limits.

The PCT2075 can be configured for different operation conditions. It can be set in normal mode to periodically monitor the ambient temperature, or in shut-down mode to minimize power consumption.

Features and benefits

■ Pin-for-pin replacement for LM75 series but allows up to 27 devices on the bus

■ Power supply range from 2.7 V to 5.5 V

■ Temperatures range from -55 °C to +125 °C

■ Frequency range 20 kHz to 1 MHz with SMBus time-out to prevent hanging up the bus

■ 1 MHz Fast-mode Plus 30 mA SDA drive allows more devices on the same bus but is

backward compatible to Fast-mode and Standard-mode

■ 11-bit ADC that offers a temperature resolution of 0.125 °C

■ Temperature accuracy of:

◆ ±1 °C (max.) from -25 °C to +100 °C

◆ ±2 °C (max.) from -55 °C to +125 °C

■ Programmable temperature threshold and hysteresis set points during operation

■ Supply current of <1.0 ?A in shut-down mode for power conservation

■ Stand-alone operation as thermostat at power-up

■ ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per

JESD22-C101

■ Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA

■ Small 8-pin package types: SO8, TSSOP8 and 2 mm x 3 mm HWSON8

■ Small 6-pin package type: TSOP6

Applications

■ System thermal management

■ Personal computers

■ Electronics equipment

■ Industrial controllers

■ Cooling system: turn on when the temperature is higher (hotter) than -5°C; turn off

when the temperature is below -10°C