Document
19-1265; Rev 1; 3/98
KIT ATION EVALU E L B A AVAIL
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 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 MAX1617 (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 twos-complement format. Measurements can be done automatically and autonomously, with the conversion rate programmed by the user or programmed to operate in a single-shot mode. The adjustable rate allows the user to control the supply-current drain. The MAX1617 is available in a small, 16-pin QSOP surface-mount package.
MAX1617 †
_______________Ordering Information
PART* MAX1617MEE TEMP. RANGE -55°C to +125°C PIN-PACKAGE 16 QSOP
________________________Applications
Desktop and Notebook Computers Smart Battery Packs LAN Servers Industrial Controls Central Office Telecom Equipment Test and Measurement Multi-Chip Modules
*U.S. and foreign patents pending.
___________________Pin Configuration
TOP VIEW
N.C. 1 VCC 2 DXP 3 DXN 4 N.C. 5 ADD1 6 GND 7 GND 8 16 N.C. 15 STBY 14 SMBCLK
__________Typical Operating Circuit
0.1µF 3V TO 5.5V 200Ω VCC STBY 10k EACH
MAX1617
DXP SMBCLK SMBDATA 2N3904 DXN 2200pF ALERT CLOCK DATA INTERRUPT TO µC
MAX1617
13 N.C. 12 SMBDATA 11 ALERT 10 ADD0 9 N.C.
ADD0 ADD1 GND
QSOP
SMBus is a trademark of Intel Corp.
†Patents Pending 1
________________________________________________________________ Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468.
Remote/Local Temperature Sensor with SMBus Serial Interface MAX1617
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.3V to +6V DXP, ADD_ to GND ....................................-0.3V to (VCC + 0.3V) D.