19-4097; Rev 0; 4/08
5-Channel Precision Temperature Monitor
with Beta Compensation
General Description
The MAX6694 precision multichannel temperature sen-
sor monitors its own temperature and the temperatures
of up to four external diode-connected transistors. All
temperature channels have programmable alert thresh-
olds. Channels 1 and 4 also have programmable
overtemperature thresholds. When the measured tem-
perature of a channel exceeds the respective thresh-
old, a status bit is set in one of the status registers. Two
open-drain outputs,
OVERT
and
ALERT,
assert corre-
sponding 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 MAX6694 is specified for a -40°C to +125°C oper-
ating temperature range and is available in 16-pin
TSSOP and 5mm x 5mm thin QFN packages.
o
Four Thermal-Diode Inputs
o
Beta Compensation (Channel 1)
o
Local Temperature Sensor
o
1.5°C Remote Temperature Accuracy (+60°C to
+100°C)
o
Temperature Monitoring Begins at POR for Fail-
Safe System Protection
o
ALERT
and
OVERT
Outputs for Interrupts,
Throttling, and Shutdown
o
STBY
Input for Hardware Standby Mode
o
Small, 16-Pin TSSOP and TQFN Packages
o
2-Wire SMBus Interface
Features
MAX6694
Applications
Desktop Computers
Notebook Computers
Workstations
Servers
SMBus is a trademark of Intel Corp.
Pin Configurations appear at end of data sheet.
PART
MAX6694UE9A+
Ordering Information
TEMP RANGE
-40°C to +125°C
PIN-PACKAGE
16 TSSOP
16 TQFN-EP*
MAX6694TE9A+
-40°C to +125°C
+Denotes
a lead-free package.
*EP
= Exposed pad.
Note:
Slave address is 1001 101.
Typical Application Circuit
+3.3V
CPU
1
100pF
2
3
100pF
4
5
100pF
6
7
100pF
8
DXN4
STBY
9
DXN3
DXP4
OVERT 11
N.C. 10
DXN2
DXP3
ALERT 13
V
CC
12
0.1µF
DXN1
DXP2
SMBCLK 15
DXP1
GND 16
4.7kΩ
EACH
CLK
DATA
INTERRUPT
TO
µP
MAX6694
SMBDATA 14
TO SYSTEM
SHUTDOWN
________________________________________________________________
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.
5-Channel Precision Temperature Monitor
with Beta Compensation
MAX6694
ABSOLUTE MAXIMUM RATINGS
V
CC
, SMBCLK, SMBDATA,
ALERT, OVERT,
STBY
to GND ....................................................-0.3V to +6.0V
DXP_ to GND..............................................-0.3V to (V
CC
+ 0.3V)
DXN_ to GND ........................................................-0.3V to +0.8V
SMBDATA,
ALERT, OVERT
Current....................-1mA to +50mA
DXIV_ Current .....................................................................±1mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TQFN, 5mm x 5mm
(derate 33.3mW/°C above +70°C)............................2666.7mW
16-Pin TSSOP
(derate 11.1mW/°C above +70°C) ............................888.9mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 1)
16-Pin TQFN...................................................................2°C/W
16-Pin TSSOP...............................................................27°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 1)
16-Pin TQFN.................................................................30°C/W
16-Pin TSSOP...............................................................90°C/W
ESD Protection (all pins, Human Body Model) ....................±2kV
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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 +3.6V, V
STBY
= V
CC
, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
=
+25°C.) (Note 2)
PARAMETER
Supply Voltage
Software Standby Supply Current
Operating Current
Temperature Resolution
3
σ
Temperature Accuracy
(Remote Channel 1)
3
σ
Temperature Accuracy
(Remote Channels 2–6)
3
σ
Temperature Accuracy
(Local)
6
σ
Temperature Accuracy
(Remote Channel 1)
6
σ
Temperature Accuracy
(Remote Channels 2–6)
6
σ
Temperature Accuracy
(Local)
Supply Sensitivity of Temperature
Accuracy
Remote Channel 1 Conversion Time
Remote Channels 2, 3, 4
Conversion Time
t
CONV1
t
CONV_
190
95
SYMBOL
V
CC
I
SS
I
CC
SMBus static
During conversion (Note 3)
Channel 1 only
Other diode channels
V
CC
= 3.3V, T
A
= T
RJ
= +60°C to +100°C
ß = 0.5
T
A
= T
RJ
= 0°C to +125°C
V
CC
= 3.3V
V
CC
= 3.3V
T
A
= T
RJ
= +60°C to +100°C
T
A
= T
RJ
= 0°C to +125°C
T
A
= +60°C to +100°C
T
A
= 0°C to +125°C
-1.5
-2.375
-2
-2.5
-2
-2.5
-3
-4
-3
-3.5
-2.5
-3
±0.2
250
125
312
156
CONDITIONS
MIN
3.0
3
500
11
8
+1.5
+2.375
+2
+2.5
+2
+2.5
+3
+4
+3
+3.5
+2.5
+3
o
TYP
MAX
3.6
10
2000
UNITS
V
µA
µA
Bits
°C
°C
°C
°C
°C
°C
C/V
ms
ms
V
CC
= 3.3V, T
A
= T
RJ
= +60°C to +100°C
ß = 0.5
T
A
= T
RJ
= 0°C to +125°C
V
CC
= 3.3V
V
CC
= 3.3V
T
A
= T
RJ
= +60°C to +100°C
T
A
= T
RJ
= 0°C to +125°C
T
A
= +60°C to +100°C
T
A
= 0°C to +125°C
2
_______________________________________________________________________________________
5-Channel Precision Temperature Monitor
with Beta Compensation
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +3.6V, V
STBY
= V
CC
, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V
CC
= +3.3V and T
A
=
+25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
High level, channel 1
Remote-Diode Source Current
I
RJ
Low level, channel 1
High level, channels 2, 3, 4
Low level, channels 2, 3, 4
Undervoltage-Lockout Threshold
Undervoltage-Lockout Hysteresis
Power-On-Reset (POR) Threshold
POR Threshold Hysteresis
ALERT, OVERT
Output Low Voltage
Output Leakage Current
SMBus INTERFACE (SMBCLK, SMBDATA),
STBY
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
V
OL
C
IN
f
SMBCLK
t
BUF
(Note 5)
f
SMBCLK
= 100kHz
f
SMBCLK
= 400kHz
f
SMBCLK
= 100kHz
f
SMBCLK
= 400kHz
90% of SMBCLK to 90% of SMBDATA,
f
SMBCLK
= 100kHz
90% of SMBCLK to 90% of SMBDATA,
f
SMBCLK
= 400kHz
10% of SMBDATA to 90% of SMBCLK
90% of SMBCLK to 90% of SMBDATA,
f
SMBCLK
= 100kHz
90% of SMBCLK to 90% of SMBDATA,
f
SMBCLK
= 400kHz
10% to 10%, f
SMBCLK
= 100kHz
10% to 10%, f
SMBCLK
= 400kHz
90% to 90%
f
SMBCLK
= 100kHz
f
SMBCLK
= 400kHz (Note 6)
4.7
1.6
4.7
0.6
0.6
µs
0.6
0.6
4
µs
0.6
1.3
1.3
0.6
300
900
µs
µs
ns
µs
I
SINK
= 6mA
5
400
V
IL
V
IH
V
CC
= 3.0V
2.2
-1
+1
0.3
0.8
V
V
µA
V
pF
kHz
µs
µs
V
OL
I
SINK
= 1mA
I
SINK
= 6mA
0.3
0.5
1
V
µA
V
CC
falling edge
1.2
UVLO
Falling edge of V
CC
disables ADC
80
8
2.30
MIN
TYP
500
20
100
10
2.80
90
2.0
90
2.25
120
12
2.95
V
mV
V
mV
µA
MAX
UNITS
MAX6694
SMBus-COMPATIBLE TIMING (Figures 3 and 4) (Note 4)
Repeat START Condition Setup
Time
START Condition Hold Time
t
SU:STA
t
HD:STA
STOP Condition Setup Time
t
SU:STO
Clock Low Period
Clock High Period
Data Hold Time
t
LOW
t
HIGH
t
HD:DAT
_______________________________________________________________________________________
3
5-Channel Precision Temperature Monitor
with Beta Compensation
MAX6694
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +3.6V, V
STBY
= V
CC
, 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
Data Setup Time
Receive SMBCLK/SMBDATA Rise
Time
Receive SMBCLK/SMBDATA Fall
Time
Pulse Width of Spike Suppressed
SMBus Timeout
SYMBOL
t
SU:DAT
t
R
t
F
t
SP
t
TIMEOUT
SMBDATA low period for interface reset
0
25
37
CONDITIONS
f
SMBCLK
= 100kHz
f
SMBCLK
= 400kHz
f
SMBCLK
= 100kHz
f
SMBCLK
= 400kHz
MIN
250
100
1
0.3
300
50
45
TYP
MAX
UNITS
ns
µs
ns
ns
ms
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
All parameters are tested at T
A
= +85°C. Specifications over temperature are guaranteed by design.
Beta = 0.5 for channel 1 remote transistor.
Timing specifications are guaranteed by design.
The serial interface resets when SMBCLK 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 SMBCLK’s falling edge.
4
_______________________________________________________________________________________
5-Channel Precision Temperature Monitor
with Beta Compensation
Typical Operating Characteristics
(V
CC
= 3.3V, V
STBY
= V
CC
, T
A
= +25°C, unless otherwise noted.)
SOFTWARE STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6694 toc01
MAX6694
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6694 toc02
REMOTE-DIODE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
CHANNEL 1
CHANNEL 2
MAX6694 toc03
3.8
3.7
SUPPLY CURRENT (µA)
3.6
3.5
3.4
3.3
3.2
3.1
3.0
3.0
3.1
3.2
3.3
3.4
3.5
650
600
SUPPLY CURRENT (µA)
550
500
450
400
350
LOW BETA DIODE CONNECTED TO
CHANNEL 1 WITH RESISTANCE
CANCELLATION AND LOW BETA
5
-5
3.0
3.2
3.4
SUPPLY VOLTAGE (V)
3.6
0
25
50
75
100
125
TEMPERATURE (°C)
3.6
SUPPLY VOLTAGE (V)
LOCAL TEMPERATURE ERROR
vs. DIE TEMPERATURE
MAX6694 toc04
REMOTE-DIODE TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
MAX6694 toc05
LOCAL TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
MAX6694 toc06
MAX6694 toc09
4
3
TEMPERATURE ERROR (°C)
2
1
0
-1
-2
-3
0
25
50
75
100
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
CHANNEL 1
CHANNEL 2
100mV
P-P
5
125
-5
0.001
0.010
0.100
1.000
10.000
-5
0.001
0.010
0.100
1.000
10.000
DIE TEMPERATURE (°C)
FREQUENCY (MHz)
FREQUENCY (MHz)
CH 2 REMOTE-DIODE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
3
TEMPERATURE ERROR (°C)
2
1
0
-1
-2
-3
-4
-5
0.1
1.0
FREQUENCY (MHz)
10.0
100mV
P-P
MAX6694 toc07
CH 1 REMOTE-DIODE TEMPERATURE
ERROR vs. CAPACITANCE
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
-5
1
10
CAPACITANCE (nF)
100
MAX6694 toc08
CH 2 REMOTE-DIODE TEMPERATURE
ERROR vs. CAPACITANCE
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
-5
1
10
CAPACITANCE (nF)
100
4
5
_______________________________________________________________________________________
5