________________General Description
The MAX1619 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 transis-
tortypically a low-cost, easily mounted 2N3904 NPN
typethat replaces conventional thermistors or thermo-
couples. Remote accuracy is ?癈 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
?/DIV>
) 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癈, 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 MAX1619 is nearly identical to the popular MAX1617A,
with the additional feature of an overtemperature alarm out-
put (OVERT) that responds to the remote temperature; this
is optimal for fan control.
________________________Applications
Desktop and Notebook
Central Office
Computers
Telecom Equipment
Smart Battery Packs
Test and Measurement
LAN Servers
Multichip Modules
Industrial Controls
____________________________Features
o Two Channels Measure Both Remote and Local
Temperatures
o No Calibration Required
o SMBus 2-Wire Serial Interface
o Programmable Under/Overtemperature Alarms
o OVERT Output for Fan Control
o Supports SMBus Alert Response
o Supports Manufacturer and Device ID Codes
o Accuracy
?癈 (+60癈 to +100癈, local)
?癈 (-40癈 to +125癈, local)
?癈 (+60癈 to +100癈, remote)
o 3?/SPAN>A (typ) Standby Supply Current
o 70?/SPAN>A (max) Supply Current in Auto-Convert Mode
o +3V to +5.5V Supply Range
o Write-Once Protection
o Small 16-Pin QSOP Package
Remote/Local Temperature Sensor with Dual-
Alarm Outputs and SMBus Serial Interface
________________________________________________________________ Maxim Integrated Products   1
MAX1619
SMBCLK
ADD0 ADD1
V
CC
STBY
GND
ALERT
SMBDATA
DXP
DXN
INTERRUPT
TO 礐
FAN
CONTROL
+3V TO +5.5V
200&
0.1礔
CLOCK
10k EACH
DATA
2N3904
2200pF
OVERT
___________________Pin Configuration
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
V
CC
N.C.
STBY
SMBCLK
N.C.
SMBDATA
ALERT
ADD0
OVERT
TOP VIEW
MAX1619
QSOP
GND
DXP
ADD1
DXN
N.C.
GND
GND
Typical Operating Circuit
19-1483; Rev 0; 4/99
PART
MAX1619MEE
-55癈 to +125癈
TEMP. RANGE
PIN-PACKAGE
16 QSOP
Ordering Information
SMBus is a registered trademark of Intel Corp.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.