19-3004; Rev 0; 12/07
7-Channel Precision Temperature Monitor
General Description
The MAX6636 precision multichannel temperature sen-
sor monitors its own temperature and the temperatures
of up to six external diode-connected transistors. All
temperature channels have programmable alert thresh-
olds. Channels 1, 4, 5, and 6 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 MAX6636 is specified for a -40°C to +125°C oper-
ating temperature range and is available in a 20-pin
TSSOP package.
♦
♦
♦
♦
♦
♦
♦
♦
♦
♦
Features
Six Thermal-Diode 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
STBY
Input for Hardware Standby Mode
Small, 20-Pin TSSOP Package
2-Wire SMBus Interface
Penryn CPU-Compatible
Pin- and Register-Compatible with MAX6689
MAX6636
Applications
Desktop Computers
Notebook Computers
Workstations
Servers
SMBus is a trademark of Intel Corp.
Pin Configuration appears at end of data sheet.
PART
Ordering Information
PIN-
PACKAGE
SLAVE
ADDRESS
PKG CODE
MAX6636UP9A+
20 TSSOP
1001 101
U20-2
Note:
Device specified over the -40°C to +125°C temperature
range.
+Denotes
lead-free package.
Typical Application Circuit
+3.3V
CPU
1
2200pF
2
3
2200pF
4
5
2200pF
6
7
2200pF
8
9
2200pF
10
DXN5
DXN6 11
DXN4
DXP5
STBY 13
DXP6 12
2200pF
GPU
DXN3
DXP4
OVERT 15
N.C. 14
TO SYSTEM
SHUTDOWN
DXN2
DXP3
ALERT 17
V
CC
16
0.1μF
INTERRUPT
TO
μP
DXN1
DXP2
DXP1
GND 20
4.7kΩ
EACH
CLK
DATA
MAX6636
SMBCLK 19
SMBDATA 18
________________________________________________________________
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 Temperature Monitor
MAX6636
ABSOLUTE MAXIMUM RATINGS
V
CC
, SCK, SDA,
ALERT, OVERT, STBY
to GND ......-0.3V to +6V
DXP_ to GND..............................................-0.3V to (V
CC
+ 0.3V)
DXN2, DXN3, DXN4, DXN5, DXN6 to GND...........-0.3V to +0.8V
SDA,
ALERT, OVERT
Current .............................-1mA to +50mA
DXN Current .......................................................................±1mA
Continuous Power Dissipation (T
A
= +70°C)
20-Pin TSSOP
(derate 11.0mW/°C above +70°C)..............................879.1mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note A)
20-Pin TSSOP...............................................................20°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note A)
20-Pin TSSOP............................................................73.8°C/W
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
Note A:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer board.
For detailed information on package thermal considerations, refer to
Application Note 4083
at 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 +5.5V, 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
Supply Voltage
Software Standby Supply Current
Operating Current
Temperature Resolution
Remote Temperature Accuracy
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
ALERT, OVERT
Output Low Voltage
Output Leakage Current
V
OL
I
SINK
= 1mA
I
SINK
= 6mA
0.3
0.5
1
V
µA
V
CC
falling edge
1.2
t
CONV1
t
CONV_
I
RJ
UVLO
High level
Low level
Falling edge of V
CC
disables ADC
Resistance cancellation off
Resistance cancellation on
95
190
95
80
8
2.30
SYMBOL
V
CC
I
SS
I
CC
SMBus static
During conversion
Channel 1 only
Other diode channels
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
-1.0
-3.0
-4.4
-6.1
±0.2
125
250
125
100
10
2.80
90
2.0
90
2.5
156
312
156
120
12
2.95
CONDITIONS
MIN
3.0
30
500
11
8
+1.0
+3.0
-0.4
-0.1
o
TYP
MAX
5.5
1000
UNITS
V
µA
µA
Bits
o
C
C
o
C/V
ms
ms
µA
V
mV
V
mV
2
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, 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
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
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
0
SDA low period for interface reset
25
37
250
100
1
0.3
300
50
45
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
ns
µs
ns
ns
ms
µs
I
SINK
= 6mA
5
400
SYMBOL
V
IL
V
IH
V
CC
= 3.0V
V
CC
= 5.0V
2.2
2.4
-1
+1
0.3
CONDITIONS
MIN
TYP
MAX
0.8
UNITS
V
V
µA
V
pF
kHz
µs
µs
SMBus INTERFACE (SCL, SDA),
STBY
MAX6636
SMBus-COMPATIBLE TIMING (Figures 3 and 4) (Note 2)
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
Data Setup Time
Receive SCL/SDA Rise Time
Receive SCL/SDA Fall Time
Pulse Width of Spike Suppressed
SMBus Timeout
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
R
t
F
t
SP
t
TIMEOUT
Note 1:
Note 2:
Note 3:
Note 4:
All parameters are tested at T
A
= +85°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 Temperature Monitor
MAX6636
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
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)
MAX6636 toc01
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6636 toc02
REMOTE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
MAX6636 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
MAX6636 toc04
REMOTE-DIODE TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
-5
100mV
P-P
MAX6636 toc05
4
3
TEMPERATURE ERROR (°C)
2
1
0
-1
-2
-3
-4
0
25
50
75
100
5
125
0.1
FREQUENCY (MHz)
1
DIE TEMPERATURE (°C)
LOCAL TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
MAX6636 toc06
REMOTE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
MAX6636 toc07
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
100mV
P-P
5
-5
0.001
0.01
0.1
1
-5
0.001
0.01
0.1
FREQUENCY (MHz)
1
10
FREQUENCY (MHz)
4
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
Typical Operating Characteristics (continued)
(V
CC
= 3.3V, V
STBY
= V
CC
, T
A
= +25°C, unless otherwise noted.)
REMOTE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
MAX6636 toc08
MAX6636
TEMPERATURE ERROR
vs. DXP-DXN CAPACITANCE
-0.5
TEMPERATURE ERROR (°C)
-1.0
-1.5
-2.0
-2.5
-3.0
-3.5
-4.0
-4.5
-5.0
MAX6636 toc09
5
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
-3
-4
-5
0.001
0.01
0.1
FREQUENCY (MHz)
1
100mV
P-P
0
10
1
10
DXP-DXN CAPACITANCE (nF)
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 unconnected 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. Internally connected to GND.
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 unconnected 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 unconnected 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 3 remote-diode-
connected transistor to DXN3.
Combined Current Source and A/D Positive Input for Channel 4 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to V
CC
if
no remote diode is used. Place a 2200pF capacitor between DXP4 and DXN4 for noise filtering.
Cathode Input for Channel 4 Remote Diode. Connect the cathode of the channel 4 remote-diode-
connected transistor to DXN4.
2
DXN1
3
DXP2
4
DXN2
5
DXP3
6
DXN3
7
DXP4
8
DXN4
_______________________________________________________________________________________
5