Datasheet MAX1618 (Maxim)

19-1495; Rev 1; 12/99
Remote Temperature Sensor with SMBus Serial Interface MAX1618 ________________General Description ____________________________Features
The MAX1618 precise digital thermometer reports the ♦
Single Channel: Measures Remote CPU
temperature of a remote sensor. The remote sensor is a
Temperature
diode-connected transistor—typically a low-cost, easily mounted 2N3904 NPN type—that replaces conventional ♦
No Calibration Required
thermistors or thermocouples. Remote accuracy is ±3°C ♦
SMBus 2-Wire Serial Interface
for multiple transistor manufacturers, with no calibration needed. The MAX1618 can also measure the die temper- ♦
Programmable Under/Overtemperature Alarms
ature of other ICs, such as microprocessors, that contain ♦
Overtemperature Output for Fan Control †
an on-chip, diode-connected transistor.
(Thermostat Mode)
The 2-wire serial interface accepts standard System ♦ Management Bus (SMBus™) Write Byte, Read Byte, Send
Supports SMBus Alert Response Accuracy
Byte, and Receive Byte commands to program the alarm
±3°C (+60°C to +100°C)
thresholds and to read temperature data. The data format
±5°C (-55°C to +120°C)
is 7 bits plus sign, with each bit corresponding to 1°C, in ♦
3µA (typ) Standby Supply Current
two’s complement format. Measurements can be done automatically and autonomously, with the 16Hz conversion ♦
900µA (max) Supply Current in Autoconvert Mode
rate or programmed to operate in a single-shot mode. ♦
+3V to +5.5V Supply Range
The thermostat mode configures the ALERT output as an ♦
Small 10-Pin µMAX Package
interrupt or as a temperature reset that remains active only while the temperature is above the maximum temperature limit or below the minimum temperature limit. The ALERT output polarity in thermostat mode can be configured for active high or active low. Fan control is implemented using
Ordering Information
this ALERT output. The MAX1618 is available in a small (1.1mm high) 10-pin
PART TEMP. RANGE PIN-PACKAGE
µMAX package. MAX1618MUB -55°C to +125°C 10 µMAX
________________________Applications
Desktop and Notebook Central Office Computers Telecom Equipment Smart Battery Packs Test and Measurement LAN Servers Multichip Modules Industrial Controls
Typical Operating Circuit ___________________Pin Configuration
3V TO 5.5V 0.1µF 200Ω TOP VIEW VCC STBY 10k EACH ADD0 1 10 ALERT MAX1618 DXP SMBCLK CLOCK ADD1 2 9 SMBDATA MAX1618 SMBDATA DATA GND 3 8 SMBCLK DXN ALERT INTERRUPT DXN 4 7 STBY 2N3904 2200pF TO µC DXP 5 6 VCC ADD0 ADD1 GND µ
MAX
SMBus is a trademark of Intel Corp. †Patents Pending
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