19-3476; Rev 3; 8/07
IT
TION K
VALUA
E
BLE
AVAILA
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
General Description
The MAX6698 precision multichannel temperature sen-
sor monitors its own temperature, the temperatures of
three external diode-connected transistors, and the
temperatures of three thermistors. All temperature
channels have programmable alert thresholds.
Channels 1, 4, 5, and 6 also have programmable over-
temperature thresholds. When the measured tempera-
ture of a channel exceeds the respective threshold, a
status bit is set in one of the status registers. Two open-
drain outputs,
OVERT
and
ALERT,
assert correspond-
ing to these bits in the status register.
The 2-wire serial interface supports the standard system
management bus (SMBus™) protocols: write byte, read
byte, send byte, and receive byte for reading the tem-
perature data and programming the alarm thresholds.
The MAX6698 is specified for an operating temperature
range of -40°C to +125°C and is available in 16-pin
QSOP and 16-pin TSSOP packages.
Features
♦
Three Thermal-Diode Inputs and Three Thermistor
Inputs
♦
Local Temperature Sensor
♦
1°C Remote Temperature Accuracy (+60°C to
+100°C)
♦
Temperature Monitoring Begins at POR for Fail-
Safe System Protection
♦
ALERT
and
OVERT
Outputs for Interrupts,
Throttling, and Shutdown
♦
Small 16-Pin QSOP and 16-Pin TSSOP Packages
♦
2-Wire SMBus Interface
MAX6698
Ordering Information
PART
MAX6698EE_ _
MAX6698UE_ _
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
PIN-
PACKAGE
16 QSOP
16 TSSOP
PKG
CODE
E16-1
U16-1
Applications
Desktop Computers
Notebook Computers
Workstations
Servers
*See
the
Slave Address
section.
Pin Configuration appears at end of data sheet.
Typical Application Circuit
+3.3V
1
2
3
4
5
6
7
8
DXP1
DXN1
DXP2
DXN2
DXP3
DXN3
THER3
VREF
GND 16
MAX6698
SMBCLK 15
SMBDATA 14
ALERT 13
V
CC
12
OVERT 11
THER1 10
THER2
9
R
EX3
R
EX2
R
EX1
R
THER3
R
THER2
R
THER1
SMBus is a trademark of Intel Corp.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
MAX6698
ABSOLUTE MAXIMUM RATINGS
V
CC
, SCL, SDA,
ALERT, OVERT
to GND ................-0.3V to +6V
DXP_ to GND..............................................-0.3V to (V
CC
+ 0.3V)
DXN_ to GND ........................................................-0.3V to +0.8V
THER_ to GND..........................................................-0.3V to +6V
VREF to GND............................................................-0.3V to +6V
SDA,
ALERT, OVERT
Current .............................-1mA to +50mA
DXN Current .......................................................................±1mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP
(derate 8.3mW/°C above +70°C) ......................666.7mW(E16-1)
16-Pin TSSOP
(derate 9.4mW/°C above +70°C)....................754.7mW(U16-1)
ESD Protection (all pins, Human Body Model) ................±2000V
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage
Standby Supply Current
Operating Current
Temperature Resolution
SYMBOL
V
CC
I
SS
I
CC
SMBus static
During conversion
Channel 1 only
Other diode channels
T
A
= T
RJ
= +60°C to +100°C
Remote Temperature Accuracy
V
CC
= 3.3V
T
A
= T
RJ
= 0°C to +125°C
DXN_ grounded,
T
RJ
= T
A
= 0°C to +85°C
T
A
= +60°C to +100°C
T
A
= 0°C to +125°C
-2.5
-3.5
±0.2
t
CONV1
t
CONV_
I
RJ
UVLO
High level
Low level
Falling edge of V
CC
disables ADC
V
CC
falling edge
Resistance cancellation on
Resistance cancellation off
95
190
95
80
8
2.3
1.2
125
250
125
100
10
2.80
90
2.0
90
2.5
156
312
156
120
12
2.95
-1.0
-3.0
CONDITIONS
MIN
3.0
30
500
11
8
+1.0
+3.0
±2.5
+2.5
+3.5
o
o
o
TYP
MAX
5.5
1000
UNITS
V
µA
µA
Bits
C
Local Temperature Accuracy
Supply Sensitivity of Temperature
Accuracy
Remote Channel 1 Conversion
Time
Remote Channels 2 Through 6
Conversion Time
Remote-Diode Source Current
Undervoltage-Lockout Threshold
Undervoltage-Lockout Hysteresis
Power-On Reset (POR) Threshold
POR Threshold Hysteresis
THERMISTOR CONVERSION
Voltage-Measurement Accuracy
Conversion Time
Thermistor Reference Voltage
V
REF
V
CC
= 3.3V
C
C/V
ms
ms
µA
V
mV
V
mV
%Full
scale
ms
V
-1
31
1
+1
2
_______________________________________________________________________________________
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
= +25°C.) (Note 1)
PARAMETER
Reference-Load Regulation
Reference-Supply Rejection
ALERT, OVERT
Output Low Voltage
Output Leakage Current
SMBus INTERFACE (SCL, SDA)
Logic-Input Low Voltage
Logic-Input High Voltage
Input Leakage Current
Output Low Voltage
Input Capacitance
Serial Clock Frequency
Bus Free Time Between STOP
and START Condition
START Condition Setup Time
Repeat START Condition Setup
Time
START Condition Hold Time
STOP Condition Setup Time
Clock Low Period
Clock High Period
Data Hold Time
Data Setup Time
Receive SCL/SDA Rise Time
Receive SCL/SDA Fall Time
Pulse Width of Spike Suppressed
SMBus Timeout
t
SU:STA
t
HD:STA
t
SU:STO
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
R
t
F
t
SP
t
TIMEOUT
SDA low period for interface reset
0
25
37
V
OL
C
IN
f
SCL
t
BUF
(Note 3)
f
SCL
= 100kHz
f
SCL
= 400kHz
f
SCL
= 100kHz
f
SCL
= 400kHz
90% of SCL to 90% of SDA, f
SCL
= 100kHz
90% of SCL to 90% of SDA, f
SCL
= 400kHz
10% of SDA to 90% of SCL
90% of SCL to 90% of SDA, f
SCL
= 100kHz
90% of SCL to 90% of SDA, f
SCL
= 400kHz
10% to 10%, f
SCL
= 100kHz
10% to 10%, f
SCL
= 400kHz
90% to 90%
f
SCL
= 100kHz
f
SCL
= 400kHz (Note 4)
f
SCL
= 100kHz
f
SCL
= 400kHz
f
SCL
= 100kHz
f
SCL
= 400kHz
250
100
1
0.3
300
50
45
4.7
1.6
4.7
0.6
0.6
0.6
0.6
4
0.6
1.3
1.3
0.6
300
900
I
SINK
= 6mA
5
400
V
IL
V
IH
V
CC
= 3.0V
V
CC
= 5.0V
2.2
2.4
-1
+1
0.3
0.8
V
V
V
µA
V
pF
kHz
µs
µs
µs
µs
µs
µs
µs
ns
ns
µs
ns
ns
ms
V
OL
I
SINK
= 1mA
I
SINK
= 6mA
0.3
0.5
1
V
µA
SYMBOL
CONDITIONS
0mA < I
REF
< 2mA
MIN
TYP
MAX
0.4
0.5
UNITS
%
%/V
MAX6698
SMBus-COMPATIBLE TIMING (Figures 3 and 4) (Note 2)
Note 1:
Note 2:
Note 3:
Note 4:
All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Timing specifications are guaranteed by design.
The serial interface resets when SCL is low for more than t
TIMEOUT
.
A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SCL’s falling edge.
_______________________________________________________________________________________
3
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
MAX6698
Typical Operating Characteristics
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.)
STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
12
11
10
9
8
7
6
5
4
3
2
1
0
3.3
3.8
4.3
4.8
5.3
SUPPLY VOLTAGE (V)
MAX6698 toc01
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6698 toc02
REMOTE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
MAX6698 toc03
360
355
SUPPLY CURRENT (µA)
350
345
340
335
330
325
320
3.3
3.8
4.3
4.8
5.3
SUPPLY VOLTAGE (V)
3
2
TEMPERATURE ERROR (°C)
1
0
-1
-2
-3
-4
0
25
50
75
100
STANDBY SUPPLY CURRENT (µA)
125
REMOTE-DIODE TEMPERATURE (°C)
LOCAL TEMPERATURE ERROR
vs. DIE TEMPERATURE
MAX6698 toc04
REMOTE-DIODE TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
MAX6698 toc05
LOCAL TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
MAX6698 toc06
4
3
TEMPERATURE ERROR (°C)
2
1
0
-1
-2
-3
-4
0
25
50
75
100
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
-5
5
100mV
P-P
125
0.1
FREQUENCY (MHz)
1
-5
0.001
0.01
0.1
1
DIE TEMPERATURE (°C)
FREQUENCY (MHz)
REMOTE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
MAX6698 toc07
REMOTE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
MAX6698 toc08
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
5
-5
0.001
0.01
0.1
FREQUENCY (MHz)
1
10
-5
0.001
0.01
0.1
FREQUENCY (MHz)
1
10
4
_______________________________________________________________________________________
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
MAX6698
MAX6698
Typical Operating Characteristics (continued)
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.)
TEMPERATURE ERROR
vs. DXP-DXN CAPACITANCE
MAX6698 toc09
ALERT, OVERT SINK CURRENT
vs. TEMPERATURE
MAX6698 toc10
THERMISTOR ADC ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
MAX6698 toc11
0
-0.5
TEMPERATURE ERROR (°C)
-1.0
-1.5
-2.0
-2.5
-3.0
-3.5
-4.0
-4.5
-5.0
1
10
DXP-DXN CAPACITANCE (nF)
30
V
OL
= 0.3V
25
ALERT SINK CURRENT (mA)
20
15
10
5
0
V
OL
= 0.1V
5
-5
0
25
50
75
100
125
0.01
0.1
1
FREQUENCY (MHz)
10
100
TEMPERATURE (°C)
100
Pin Description
PIN
1
NAME
DXP1
FUNCTION
Combined Current Source and A/D Positive Input for Channel 1 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave floating or connect to V
CC
if no
remote diode is used. Place a 2200pF capacitor between DXP1 and DXN1 for noise filtering.
Cathode Input for Channel 1 Remote Diode. Connect the cathode of the channel 1 remote-diode-
connected transistor to DXN1.
Combined Current Source and A/D Positive Input for Channel 2 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave floating or connect to V
CC
if no
remote diode is used. Place a 2200pF capacitor between DXP2 and DXN2 for noise filtering.
Cathode Input for Channel 2 Remote Diode. Connect the cathode of the channel 2 remote-diode-
connected transistor to DXN2.
Combined Current Source and A/D Positive Input for Channel 3 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave floating or connect to V
CC
if no
remote diode is used. Place a 2200pF capacitor between DXP3 and DXN3 for noise filtering.
Cathode Input for Channel 3 Remote Diode. Connect the cathode of the channel 1 remote-diode-
connected transistor to DXN3.
Thermistor Voltage Sense Input 3. Connect thermistor 3 between THER3 and ground and an external
resistor R
EXT3
between THER3 and VREF.
Thermistor Reference Voltage (1V Nominal). VREF is automatically enabled for a thermistor
conversion, and is disabled for diode measurements.
2
DXN1
3
DXP2
4
DXN2
5
DXP3
6
7
8
DXN3
THER3
VREF
_______________________________________________________________________________________
5
