19-1483; Rev 0; 4/99
Remote/Local Temperature Sensor with DualAlarm Outputs and SMBus Serial Interface
____________________________Features
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 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 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®) 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 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 output (OVERT) that responds to the remote temperature; this
is optimal for fan control.
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
±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 Write-Once Protection
o Small 16-Pin QSOP Package
Ordering Information
________________________Applications
Desktop and Notebook
Computers
Central Office
Telecom Equipment
Smart Battery Packs
LAN Servers
PART
MAX1619MEE
Test and Measurement
Multichip Modules
TEMP. RANGE
-55°C to +125°C
PIN-PACKAGE
16 QSOP
Typical Operating Circuit
Industrial Controls
+3V TO +5.5V
200Ω
0.1µF
___________________Pin Configuration
TOP VIEW
VCC
VCC 1
15 STBY
10k EACH
16 N.C.
GND 2
STBY
MAX1619
DXP
14 SMBCLK
DXP 3
DXN 4
MAX1619
SMBDATA
13 N.C.
12 SMBDATA
N.C. 5
ADD1 6
11 ALERT
GND 7
10 ADD0
GND 8
9
SMBCLK
2N3904
DXN
2200pF
ALERT
OVERT
CLOCK
DATA
INTERRUPT
TO µC
FAN
CONTROL
ADD0 ADD1 GND
OVERT
QSOP
SMBus is a registered trademark of Intel Corp.
________________________________________________________________ Maxim Integrated Products
1
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.
MAX1619
________________General Description
