SE95DP datasheet(5/27 Pages) NXP

5 / 27 page

SE95_7

Product data sheet

Rev. 07 — 2 September 2009

5 of 27

NXP Semiconductors

SE95

Ultra high accuracy digital temperature sensor and thermal watchdog

In OS interrupt mode, the OS output is used for thermal interruption. When the device is

powered-up, the OS output is ﬁrst activated only when Temp exceeds Tos; then it remains

active indeﬁnitely until being reset by a read of any register. Once the OS output has been

activated by crossing Tos and then reset, it can be activated again only when Temp drops

below Thyst; then again, it remains active indeﬁnitely until being reset by a read of any

Thyst trip, reset, Tos trip, reset, Thyst trip, reset, and etc. Putting the device into shutdown

mode also resets the OS output.

In both cases, comparator mode and interrupt mode, the OS output is activated only if a

number of consecutive faults, deﬁned by the device fault queue, has been met. The fault

queue is programmable and stored in bits OS_F_QUE[1:0], of register Conf. Also, the OS

output active state is selectable as HIGH or LOW by setting accordingly the bit OS_POL

of register Conf.

At power-up, the device is put into normal operation mode, register Tos is set to 80

°C,

°C, OS active state is selected LOW and the fault queue is equal

to 1. The data reading of register Temp is not available until the ﬁrst conversion is

completed in about 33 ms.

The OS response to the temperature is illustrated in Figure 4.

(1) OS is reset by either reading register or putting the device in shutdown mode. Assumed that the

fault queue is met at each Tos and Thyst crossing point.

Fig 4.

OS response to temperature

001aad623

(1)

Tos

Thyst

OS RESET

OS ACTIVE

OS RESET

OS ACTIVE

OS output in comparator mode

OS output in interrupt mode

reading temperature limits

SE95DP Datasheet(PDF) 5 Page - NXP Semiconductors