DESCRIPTION

The NE1617 is an accurate two-channel temperature monitor. It measures the temperature of itself and the temperature of a remote sensor. The remote sensor is a diode connected transistor. This can be in the form of either a discrete NPN/PNP, such as the 2N3904/2N3906, or a diode connected PNP built into another die, such as is done on some INTEL microprocessors.

The temperature of both the remote and local sensors is stored in a register that can be read via a 2-wire SMBus. The temperatures are updated at a rate that is programmable via the SMBus (the average supply current is dependent upon the update rate—the faster the rate, the higher the current).

In addition to the normal operation, which is to update the temperature at the programmed rate, there is a one shot mode that will force a temperature update.

There is also an alarm that senses either an over or under temperature condition. The trip points for this alarm are also programmable.

The device can have 1 of 9 addresses (determined by 2 address pins), so there can be up to 9 of the NE1617 on the SMBus.

It can also be put in a standby mode (in order to save power). This can be done either with software (over the SMBus) or with hardware (using the STANDBY pin).

FEATURES

• Replacement for Maxim MAX1617 and Analog Devices ADM1021

• Monitors local and remote temperature

• Accuracy

– ± 2°C local (on-chip) sensor

– ± 3°C remote sensor

• No calibration required

• Programmable over/under temperature alarm

• SMBus 2-wire serial interface

• 3V to 5.5V supply range

• 70µa supply current in operating mode

• 3µa (typical) supply current in standby mode

• Small 16–lead QSOP package

APPLICATIONS

• Desktop computers

• Notebook computers

• Smart battery packs

• Industrial controllers

• Telecom equipment