1.

General description

The SE95 is a temperature-to-digital converter using an on-chip band gap temperature

sensor and Sigma Delta analog-to-digital conversion technique. The device is also a

thermal detector providing an overtemperature detection output.

The SE95 contains a number of data registers accessed by a controller via the 2-wire

device operation mode, OS operation mode, OS polarity, and OS fault queue

and hysteresis limits

The device includes an open-drain output (pin OS) which becomes active when the

temperature exceeds the programmed limits. There are three selectable logic address

pins (pins A2 to A0) so that eight devices can be connected on the same bus without

address conflict.

The SE95 can be configured for different operation conditions. It can be set in normal

mode to periodically monitor the ambient temperature, or in shutdown mode to minimize

power consumption. The OS output operates in either of two selectable modes: OS

comparator mode and 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 temperature register always stores a 13-bit two’s complement data giving a

temperature resolution of 0.03125

°C. This high temperature resolution is particularly

useful in applications of measuring precisely the thermal drift or runaway. For normal

operation and compatibility with the LM75A, only the 11 MSBs are read, with a resolution

of 0.125

°C to provide the accuracies specified. To be compatible with the LM75, read only

the 9 MSBs.

The device is powered-up in normal operation mode with the OS in comparator mode,

temperature threshold of 80

°C and hysteresis of 75 °C, so that it can be used as a

stand-alone thermostat with those pre-defined temperature set points. The conversion

rate is programmable, with a default of 10 conversions/s.

SE95

Ultra high accuracy digital temperature sensor and thermal

watchdog

Rev. 07 — 2 September 2009

Product data sheet