Rainbow Electronics MAX1618 - Manual

________________General Description
The MAX1618 precise digital thermometer reports the
temperature of a remote sensor. 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 MAX1618 can also measure the die temper-
ature 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. Measurements can be done
automatically and autonomously, with the 16Hz conversion
rate or programmed to operate in a single-shot mode.
The thermostat mode configures the ALERT output as an
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
this ALERT output.
The MAX1618 is available in a small (1.1mm high) 10-pin
µMAX package.
________________________Applications
Desktop and Notebook Central Office
Computers Telecom Equipment
Smart Battery Packs Test and Measurement
LAN Servers Multichip Modules
Industrial Controls
____________________________Features
♦ Single Channel: Measures Remote CPU
Temperature
♦ No Calibration Required
♦ SMBus 2-Wire Serial Interface
♦ Programmable Under/Overtemperature Alarms
♦ Overtemperature Output for Fan Control
(Thermostat Mode)
♦ Supports SMBus Alert Response Accuracy
±3°C (+60°C to +100°C)
±5°C (-55°C to +120°C)
♦ 3µA (typ) Standby Supply Current
♦ 900µA (max) Supply Current in Autoconvert Mode
♦ +3V to +5.5V Supply Range
♦ Small 10-Pin µMAX Package
MAX1618
†
Remote Temperature Sensor
with SMBus Serial Interface
________________________________________________________________ Maxim Integrated Products 1
MAX1618
SMBCLK
ADD0 ADD1
V CC STBY
GND
ALERT
SMBDATA
DXP
DXN INTERRUPT
TO
µC
3V TO 5.5V
200 Ω
0.1 µF
CLOCK
10k EACH
DATA
2N3904 2200pF
___________________Pin Configuration
1
2
3
4
5
10
9
8
7
6
ALERT
SMBDATA
SMBCLK
STBY DXN
GND
ADD1
ADD0
MAX1618
µMAX
TOP VIEW
V CC DXP
Typical Operating Circuit
19-1495; Rev 1; 12/99
PART
MAX1618MUB -55°C to +125°C
TEMP. RANGE PIN-PACKAGE
10 µMAX
Ordering Information
SMBus is a trademark of Intel Corp.
†Patents Pending
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.