MAX1668/MAX1805†
19-1766; Rev 0; 8/00
Multichannel Remote/Local Temperature Sensor
________________General Descriptio...
MAX1668/MAX1805†
19-1766; Rev 0; 8/00
Multichannel Remote/Local Temperature Sensor
________________General Description
The MAX1668/MAX1805 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 lowcost, 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.
The 2-wire serial interface accepts standard System Management Bus (SMBus™) Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read temperature data. The data format is 7 bits plus sign, with each bit corresponding to 1°C, in two’s-complement format.
The MAX1668/MAX1805 are available in small, 16-pin QSOP surface-mount packages.
________________________Applications
Desktop and Notebook Computers
Central Office Telecom Equipment
LAN Servers
Test and Measurement
Industrial Controls
Multichip Modules
____________________________Features
o Multichannel 4 Remote, 1 Local (MAX1668) 2 Remote, 1 Local (MAX1805)
o No Calibration Required
o SMBus 2-Wire Serial Interface
o Programmable Under/Overtemperature Alarms
o Supports SMBus Alert Response
o Accuracy ±2°C (+60°C to +100°C, local...