MAX1668_00 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Multichannel Remote/Local Temperature Sensor

19-1766; Rev 0; 8/00
Multichannel Remote/Local
Temperature Sensor
________________General Description
The MAX1668/MAX1805 are precise multichannel digi-
tal thermometers that report the temperature of all
remote sensors and their own packages. The remote
sensors are diode-connected transistors—typically low-
cost, easily mounted 2N3904 NPN types—that replace
conventional thermistors or thermocouples. Remote
accuracy is ±3°C for multiple transistor manufacturers,
with no calibration needed. The remote channels 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 two’s-complement format.
The MAX1668/MAX1805 are available in small, 16-pin
QSOP surface-mount packages.
________________________Applications
Desktop and Notebook
Computers
Central Office Telecom
Equipment
LAN Servers
Test and Measurement
Industrial Controls
Multichip Modules
____________________________Features
o Multichannel
4 Remote, 1 Local (MAX1668)
2 Remote, 1 Local (MAX1805)
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 700µA (max) Supply Current
o Small, 16-Pin QSOP Package
_______________Ordering Information
PART
MAX1668MEE
MAX1805MEE
TEMP. RANGE
-55°C to +125°C
-55°C to +125°C
PIN-PACKAGE
16 QSOP
16 QSOP
Pin Configurations
Typical Operating Circuit
TOP VIEW
DXP1 1
DXN1 2
DXP2 3
DXN2 4
(N.C.) DXP3 5
(N.C.) DXN3 6
(N.C.) DXP4 7
(N.C.) DXN4 8
( ) ARE FOR MAX1805.
MAX1668
MAX1805
QSOP
16 GND
15 STBY
14 SMBCLK
13 SMBDATA
12 ALERT
11 ADD0
10 ADD1
9 V_CC
0.1µF
3V TO 5.5V
200Ω
2200pF
*
2200pF
*
V_CC STBY
MAX1668
MAX1805
DXP1
SMBCLK
DXN1
SMBDATA
ALERT
DXP4
DXN4
ADD0 ADD1 GND
10k EACH
CLOCK
DATA
INTERRUPT
TO µC
* DIODE-CONNECTED TRANSISTOR
SMBus is a trademark of Intel Corp.
†Patents Pending
________________________________________________________________ Maxim Integrated Products 1
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