19-1265; Rev 1; 3/98
KIT
ATION
EVALU
BLE
AVAILA
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 con-
ventional thermistors or thermocouples. Remote accu-
racy 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-con-
nected 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 conver-
sion 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 sur-
face-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
V
CC
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
V
CC
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
