MAX1617A

19-4508; Rev 0; 1/99 UAL IT MAN TION K A ET U E L H A S EV TA WS DA FOLLO Remote/Local Temperature Sensor with SMBus Serial Interface ____________________________Features o Two Channels: Measures Both Remote and Local Temperatures o No Calibration Required o SMBus 2-Wire Serial Interface o Programmable Under/Overtemperature Alarms o Supports SMBus Alert Response o Supports Manufacturer and Device ID Codes o 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) o 3µA (typ) Standby Supply Current o 70µA (max) Supply Current in Auto-Convert Mode o +3V to +5.5V Supply Range o Small 16-Pin QSOP Package ________________General Description The MAX1617A (patents pending) is a precise digital thermometer that reports the temperature of both a remote sensor and its own package. The remote sensor is a diode-connected transistor—typically a low-cost, easily mounted 2N3904 NPN type—that replaces conventional thermistors or thermocouples. Remote accuracy is ±3°C for multiple transistor manufacturers, with no calibration needed. The remote channel 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...