________________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 3C 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 (SMBusTM) 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
1C, 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.
________________________Applications
Desktop and Notebook
Central Office
Computers
Telecom Equipment
Smart Battery Packs
Test and Measurement
LAN Servers
Multi-Chip Modules
Industrial Controls
____________________________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:
2C (+60C to +100C, local)
3C (-40C to +125C, local)
3C (+60C to +100C, remote)
o
3A (typ) Standby Supply Current
o
70A (max) Supply Current in Auto-Convert Mode
o
+3V to +5.5V Supply Range
o
Small, 16-Pin QSOP Package
MAX1617
Remote/Local Temperature Sensor
with SMBus Serial Interface
________________________________________________________________
Maxim Integrated Products
1
MAX1617
SMBCLK
ADD0 ADD1
V
CC
STBY
GND
ALERT
SMBDATA
DXP
DXN
INTERRUPT
TO
C
3V TO 5.5V
200
0.1
F
CLOCK
10k EACH
DATA
2N3904
2200pF
___________________Pin Configuration
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
N.C.
N.C.
STBY
SMBCLK
N.C.
SMBDATA
ALERT
ADD0
N.C.
TOP VIEW
MAX1617
QSOP
V
CC
DXP
ADD1
DXN
N.C.
GND
GND
__________Typical Operating Circuit
19-1265; Rev 1; 3/98
PART*
MAX1617MEE
-55C to +125C
TEMP. RANGE
PIN-PACKAGE
16 QSOP
EVALUATION KIT
AVAILABLE
_______________Ordering Information
SMBus is a 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 408-737-7600 ext. 3468.
*
U.S. and foreign patents pending.
Patents Pending
MAX161
7
Remote/Local Temperature Sensor
with SMBus Serial Interface
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.3V,
T
A
= 0C to +85C
, unless otherwise noted.)
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
V
CC
to GND ..............................................................-0.3V to +6V
DXP, ADD_ to GND ....................................-0.3V to (V
CC
+ 0.3V)
DXN to GND ..........................................................-0.3V to +0.8V
SMBCLK, SMBDATA, ALERT, STBY to GND ...........-0.3V to +6V
SMBDATA, ALERT Current .................................-1mA to +50mA
DXN Current .......................................................................1mA
ESD Protection (SMBCLK, SMBDATA,
ALERT, human body model) .......................................... 4000V
ESD Protection (other pins, human body model)...............2000V
Continuous Power Dissipation (T
A
= +70C)
QSOP (derate 8.30mW/C above +70C) .....................667mW
Operating Temperature Range .........................-55C to +125C
Junction Temperature ......................................................+150C
Storage Temperature Range .............................-65C to +165C
Lead Temperature (soldering, 10sec) .............................+300C
T
A
= +60C to +100C
Monotonicity guaranteed
ADD0, ADD1; momentary upon power-on reset
DXP forced to 1.5V
Logic inputs
forced to V
CC
or GND
Auto-convert mode
From stop bit to conversion complete (both channels)
V
CC
, falling edge
T
A
= 0C to +85C
V
CC
input, disables A/D conversion, rising edge
Auto-convert mode, average
measured over 4sec. Logic
inputs forced to V
CC
or GND.
CONDITIONS
A
160
Address Pin Bias Current
V
0.7
DXN Source Voltage
A
8
10
12
80
100
120
Remote-Diode Source Current
%
-25
25
Conversion Rate Timing Error
ms
94
125
156
Conversion Time
A
120
180
35
70
Average Operating Supply Current
-2
2
Bits
8
Temperature Resolution (Note 1)
A
4
Standby Supply Current
3
10
mV
50
POR Threshold Hysteresis
V
1.0
1.7
2.5
Power-On Reset Threshold
C
-3
3
Initial Temperature Error,
Local Diode (Note 2)
V
3.0
5.5
Supply-Voltage Range
V
2.60
2.80
2.95
Undervoltage Lockout Threshold
mV
50
Undervoltage Lockout Hysteresis
UNITS
MIN
TYP
MAX
PARAMETER
T
R
= +60C to +100C
T
R
= -55C to +125C
-3
3
C
-5
5
Temperature Error, Remote Diode
(Notes 2 and 3)
Including long-term drift
-2.5
2.5
C
-3.5
3.5
Temperature Error, Local Diode
(Notes 1 and 2)
0.25 conv/sec
2.0 conv/sec
T
A
= +60C to +100C
T
A
= 0C to +85C
High level
Low level
ADC AND POWER SUPPLY
SMBus static
Hardware or software standby, SMB-
CLK at 10kHz
MAX161
7
Remote/Local Temperature Sensor
with SMBus Serial Interface
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.3V,
T
A
= 0C to +85C
, unless otherwise noted.)
STBY, SMBCLK, SMBDATA; V
CC
= 3V to 5.5V
t
HIGH
, 90% to 90% points
t
LOW
, 10% to 10% points
(Note 4)
SMBCLK, SMBDATA
Logic inputs forced to V
CC
or GND
ALERT forced to 5.5V
STBY, SMBCLK, SMBDATA; V
CC
= 3V to 5.5V
ALERT, SMBDATA forced to 0.4V
CONDITIONS
s
4
SMBCLK Clock High Time
s
4.7
SMBCLK Clock Low Time
kHz
DC
100
SMBus Clock Frequency
pF
5
SMBus Input Capacitance
A
-1
1
Logic Input Current
A
1
ALERT Output High Leakage
Current
V
2.2
Logic Input High Voltage
V
0.8
Logic Input Low Voltage
mA
6
Logic Output Low Sink Current
UNITS
MIN
TYP
MAX
PARAMETER
t
SU:DAT
, 10% or 90% of SMBDATA to 10% of SMBCLK
t
SU:STO
, 90% of SMBCLK to 10% of SMBDATA
t
HD:STA
, 10% of SMBDATA to 90% of SMBCLK
t
SU:STA
, 90% to 90% points
ns
800
SMBus Data Valid to SMBCLK
Rising-Edge Time
s
4
SMBus Stop-Condition Setup Time
s
4
SMBus Start-Condition Hold Time
ns
500
SMBus Repeated Start-Condition
Setup Time
s
4.7
SMBus Start-Condition Setup Time
t
HD:DAT
(Note 5)
s
0
SMBus Data-Hold Time
Master clocking in data
s
1
SMBCLK Falling Edge to SMBus
Data-Valid Time
SMBus INTERFACE
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.3V,
T
A
= -55C to +125C
, unless otherwise noted.) (Note 6)
CONDITIONS
Monotonicity guaranteed
T
A
= +60C to +100C
Bits
8
Temperature Resolution (Note 1)
-2
2
T
R
= +60C to +100C
T
A
= -55C to +125C
C
-3
3
Initial Temperature Error,
Local Diode (Note 2)
V
3.0
5.5
Supply-Voltage Range
From stop bit to conversion complete (both channels)
Auto-convert mode
ms
94
125
156
Conversion Time
%
-25
25
Conversion Rate Timing Error
-3
3
T
R
= -55C to +125C
C
UNITS
MIN
TYP
MAX
-5
5
PARAMETER
Temperature Error, Remote Diode
(Notes 2 and 3)
ADC AND POWER SUPPLY
0
6
3
9
12
50
5k
500k
50k
5M
500
50M
TEMPERATURE ERROR vs.
POWER-SUPPLY NOISE FREQUENCY
MAX1617TOC04
FREQUENCY (Hz)
TEMPERATURE ERROR (C)
V
IN
= SQUARE WAVE APPLIED TO
V
CC
WITH NO 0.1
F V
CC
CAPACITOR
V
IN
= 250mVp-p
REMOTE DIODE
V
IN
= 250mVp-p
LOCAL DIODE
V
IN
= 100mVp-p
REMOTE DIODE
-20
-10
0
10
20
1
10
30
3
100
TEMPERATURE ERROR
vs. PC BOARD RESISTANCE
MAX1617TOC01
LEAKAGE RESISTANCE (M
)
TEMPERATURE ERROR (C)
PATH = DXP TO V
CC
(5V)
PATH = DXP TO GND
-2
-1
0
1
2
-50
50
100
0
150
TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
MAX1617TOC02
TEMPERATURE (C)
TEMPERATURE ERROR (C)
SAMSUNG KST3904
MOTOROLA MMBT3904
ZETEX FMMT3904
RANDOM
SAMPLES
__________________________________________Typical Operating Characteristics
(T
A
= +25C, unless otherwise noted.)
MAX161
7
Remote/Local Temperature Sensor
with SMBus Serial Interface
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.3V,
T
A
= -55C to +125C
, unless otherwise noted.) (Note 6)
Note 1:
Guaranteed but not 100% tested.
Note 2:
Quantization error is not included in specifications for temperature accuracy. For example, if the MAX1617 device tempera-
ture is exactly +66.7C, the ADC may report +66C, +67C, or +68C (due to the quantization error plus the +1/2C offset
used for rounding up) and still be within the guaranteed 1C error limits for the +60C to +100C temperature range. See
Table 2.
Note 3:
A remote diode is any diode-connected transistor from Table 1. T
R
is the junction temperature of the remote diode. See
Remote Diode Selection for remote diode forward voltage requirements.
Note 4:
The SMBus logic block is a static design that works with clock frequencies down to DC. While slow operation is possible, it
violates the 10kHz minimum clock frequency and SMBus specifications, and may monopolize the bus.
Note 5:
Note that a transition must internally provide at least a hold time in order to bridge the undefined region (300ns max) of
SMBCLK's falling edge.
Note 6:
Specifications from -55C to +125C are guaranteed by design, not production tested.
CONDITIONS
UNITS
MIN
TYP
MAX
PARAMETER
STBY, SMBCLK, SMBDATA
2.2
Logic Input High Voltage
V
2.4
STBY, SMBCLK, SMBDATA; V
CC
= 3V to 5.5V
V
0.8
Logic Input Low Voltage
ALERT forced to 5.5V
A
1
ALERT Output High Leakage
Current
Logic inputs forced to V
CC
or GND
A
-2
2
Logic Input Current
V
CC
= 3V
V
CC
= 5.5V
ALERT, SMBDATA forced to 0.4V
mA
6
Logic Output Low Sink Current
SMBus INTERFACE
MAX161
7
Remote/Local Temperature Sensor
with SMBus Serial Interface
_______________________________________________________________________________________
5
0
10
20
30
50
5k
500k
50k
5M
500
50M
TEMPERATURE ERROR vs.
COMMON-MODE NOISE FREQUENCY
MAX1617TOC05
FREQUENCY (Hz)
TEMPERATURE ERROR (C)
V
IN
= SQUARE WAVE
AC COUPLED TO DXN
V
IN
= 100mVp-p
V
IN
= 50mVp-p
V
IN
= 25mVp-p
-5
5
0
10
50
5k
500k
50k
5M
500
50M
TEMPERATURE ERROR vs.
DIFFERENTIAL-MODE NOISE FREQUENCY
MAX1617TOC06
FREQUENCY (Hz)
TEMPERATURE ERROR (C)
V
IN
= 10mVp-p SQUARE WAVE
APPLIED TO DXP-DXN
0
10
20
0
40
60
80
20
100
TEMPERATURE ERROR vs.
DXPDXN CAPACITANCE
MAX1617TOC07
DXP-DXN CAPACITANCE (nF)
TEMPERATURE ERROR (C)
V
CC
= 5V
0
100
400
200
300
500
0
1
0.0625
4
0.25
2
0.125
0.5
8
OPERATING SUPPLY CURRENT
vs. CONVERSION RATE
MAX1617TOC10
CONVERSION RATE (Hz)
SUPPLY CURRENT (
A)
V
CC
= 5V
AVERAGED MEASUREMENTS
0
5
15
25
10
20
30
35
1k
100k
10k
1000k
STANDBY SUPPLY CURRENT
vs. CLOCK FREQUENCY
MAX1617TOC08
SMBCLK FREQUENCY (Hz)
SUPPLY CURRENT (
A)
V
CC
= 5V
V
CC
= 3.3V
SMBCLK IS
DRIVEN RAIL-TO-RAIL
0
3
60
6
20
100
0
3
1
4
2
5
STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1617TOC09
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
A)
ADD0,
ADD1
= GND
ADD0,
ADD1
= HIGH-Z
0
25
100
50
75
125
T = -2
T = 8
T = 0
T = 4
T = 2
T = 6
T = 10
RESPONSE TO THERMAL SHOCK
MAX1617TOC11
TIME (sec)
TEMPERATURE (C)
16-QSOP IMMERSED
IN +115C FLUORINERT BATH
____________________________Typical Operating Characteristics (continued)
(T
A
= +25C, unless otherwise noted.)
-5
0
5
50
5k
500k
50k
5M
500
50M
TEMPERATURE ERROR vs.
DIFFERENTIAL-MODE NOISE FREQUENCY
MAX1617TOC03
FREQUENCY (Hz)
TEMPERATURE ERROR (C)
V
IN
= 3mVp-p SQUARE WAVE
APPLIED TO DXP-DXN
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