General Description

The MAX1668/MAX1805/MAX1989 are precise multichannel digital thermometers that report the temperature of all remote sensors and their own packages. The remote sensors are diode-connected transistors—typically low-cost, easily mounted 2N3904 NPN types—that replace conventional thermistors or thermocouples. Remote accuracy is ±3°C for multiple transistor manufacturers, with no calibration needed. The remote channels can also measure the die temperature of other ICs, such as microprocessors, that contain an on-chip, diode-connected transistor.

Features

♦ Multichannel

4 Remote, 1 Local (MAX1668/MAX1989)

2 Remote, 1 Local (MAX1805)

♦ No Calibration Required

♦ SMBus 2-Wire Serial Interface

♦ Programmable Under/Overtemperature Alarms

♦ Supports SMBus Alert Response

♦ Accuracy

±2°C (+60°C to +100°C, Local)

±3°C (-40°C to +125°C, Local)

±3°C (+60°C to +100°C, Remote)

♦ 3µA (typ) Standby Supply Current

♦ 700µA (max) Supply Current

♦ Small, 16-Pin QSOP/TSSOP Packages

Applications

Desktop and Notebook Computers

LAN Servers

Industrial Controls

Central-Office Telecom Equipment

Test and Measurement

Multichip Modules