19-1819; Rev 3; 2/11
Low-Cost, Remote Temperature Switch
General Description
The MAX6513 is a fully integrated, remote temperature
switch that uses an external P-N junction (typically a
diode-connected transistor) as the sensing element to
measure the remote temperature. The device asserts a
logic signal when the temperature crosses a factory-
programmed threshold. Available trip thresholds are
from +45°C to +125°C in 10°C increments. Accuracy is
within ±3°C (T
A
= -5°C to +55°C) or ±5°C (T
A
= -40°C
to +85°C). Hysteresis is pin selectable to 5°C or 10°C.
The MAX6513 has an active-high CMOS output. The
output is asserted when the temperature exceeds the
threshold value. The active-high CMOS output can
directly drive a power FET to control a cooling fan.
The MAX6513 operates from a +3.0V to +5.5V supply
and typically consumes 400µA of supply current. It is
available in a 6-pin lead-free TDFN package.
Features
♦
Continuously Measure External Junction
Temperature
♦
Factory-Programmed Temperature Threshold
from +45°C to +125°C in 10°C Increments
♦
Insensitive to Series Parasitic Resistance
♦
Active-High Output for Direct Fan Control
♦
< 100ms Response Time
♦
Accuracy
±3°C (T
REMOTE
= +45°C to +125°C, T
A
= -5°C to +55°C)
±5°C (T
REMOTE
= +45°C to +125°C, T
A
= -40°C to +85°C)
♦
Pin-Selectable 5°C or 10°C Hysteresis
♦
400µA Average Current Consumption
♦
+3.0V to +5.5V Supply Range
♦
6-Pin TDFN Package (Lead(Pb)-Free) with
Exposed Pad
MAX6513
Applications
CPU Temperature Monitoring in High-Speed
Computers
Multichip Modules
Battery Packs
Temperature Control
Temperature Alarms
Fan Control
PART
MAX6513TT_ _ _ +T
Ordering Information
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
6 TDFN-EP*
Note:
These parts are offered in nine standard temperature
versions with a minimum order of 2500 pieces. To complete
the suffix information, select an available trip point in degrees
centigrade from the device marking codes table. For example,
the MAX6513TT065+T describes a MAX6513 in a 6-pin TDFN
package with a +65°C threshold.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP
= Exposed pad.
Typical Operating Circuit
3.3V
V
DD
μP
C
S
DXP
DXN
HYST
MAX6513
2μF
TOVER (TO MICROPROCESSOR FAN
CONTROLLER, SHUTDOWN, ETC.)
________________________________________________________________
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.
Low-Cost, Remote Temperature Switch
MAX6513
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
DD
) ...............................................-0.3V to +6V
DXP, DXN, HYST, TOVER...........................-0.3V to (V
DD
+ 0.3V)
TOVER Output Current............................................-1mA/+50mA
DXN Input Current...................................................-1mA/+50mA
Current (all other pins)......................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
TDFN (derate 18.2mW/°C above +70°C)...................1455mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature ....................................................+260°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
DD
= +3.0V to +5.5V, C
S
= 2200pF, T
A
= -40°C to +85°C, T
REMOTE
= +45°C to +125°C (Note 1), unless otherwise noted. Typical
values are at T
A
= +25°C.) (Note 2)
PARAMETER
Supply Voltage Range
Supply Current
Temperature Threshold
Accuracy (Note 3)
Power-Supply Sensitivity for
Temperature Trip Point
Temperature Threshold
Hysteresis
Response Time
Input Voltage High
Input Voltage Low
Output Voltage High
Output Voltage Low
Maximum DXP Source
Current
Minimum DXP Source
Current
V
IH
V
IL
V
OH
V
OL
I
OUT
= 1mA
I
OUT
= 1mA
0.4V V
DXP
DXN = GND
0.4V V
DXP
DXN = GND
2V,
2V,
270
9
V
DD
-
0.2
0.2
V
DD
-
0.2
0.2
T
HYST
HYST = V
IL
HYST = V
IH
SYMBOL
V
DD
I
DD
T
TH
T
A
= -5°C to +55°C
T
A
= -40°C to +85°C
-3.0
-5.0
-0.6
5
10
70
120
CONDITIONS
MIN
3.0
400
TYP
MAX
5.5
600
+3.0
+5.0
UNITS
V
μA
°C
°C/V
°C
ms
V
V
V
V
μA
μA
Note 1:
Note 2:
Note 3:
T
REMOTE
refers to the temperature of the remote-sensing junction. T
A
refers to the temperature of the MAX6513 package.
All parameters are 100% production tested at T
A
= +25°C. Specifications over temperature limits are guaranteed by design.
This parameter is guaranteed by design to ±3.5 sigma.
2
_______________________________________________________________________________________
Low-Cost, Remote Temperature Switch
Typical Operating Characteristics
(V
DD
= +3.3V, C
S
= 2200pF, T
A
= +25°C, unless otherwise noted.)
MAX6513
SUPPLY CURRENT
vs. AMBIENT TEMPERATURE
MAX6511 toc01
TEMPERATURE TRIP THRESHOLD ERROR
vs. AMBIENT TEMPERATURE T
A
MAX6511 toc02
TEMPERATURE TRIP THRESHOLD ERROR
vs. C
S
CAPACITANCE
TEMPERATURE TRIP THRESHOLD ERROR (°C)
12
10
8
6
4
2
0
-2
-4
0
10
20
30
40
50
60
MAX6511 toc03
TEMPERATURE TRIP THRESHOLD ERROR (°C)
440
420
SUPPLY CURRENT (μA)
400
380
360
340
320
300
-40
-15
10
35
60
(NOTE: SUPPLY CURRENT
INCLUDES EXTERNAL
DIODE-CONNECTED
TRANSISTOR)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
-1.6
-60 -40 -20 0
14
85
20 40 60 80 100 120 140
AMBIENT TEMPERATURE T
A
(°C)
AMBIENT TEMPERATURE T
A
(°C)
C
S
CAPACITANCE (nF)
TEMPERATURE TRIP THRESHOLD ERROR
vs. SERIES RESISTANCE
TEMPERATURE TRIP THRESHOLD ERROR (°C)
MAX6511 toc04
TEMPERATURE TRIP THRESHOLD
vs. SUPPLY VOLTAGE
TEMPERATURE TRIP THRESHOLD ERROR (°C)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
-1.6
-1.8
3.0
3.5
4.0
4.5
5.0
5.5
MAX6511 toc05
1.0
0.5
0
-0.5
-1.0
-1.5
-2.0
0
0.4
20 40 60 80 100 120 140 160 180 200
SERIES RESISTANCE (Ω)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
3
Low-Cost, Remote Temperature Switch
MAX6513
Pin Configuration
TOP VIEW
+
V
DD
1
MAX6513
6
DXP
Detailed Description
The MAX6513 fully integrated temperature switch incor-
porates a precision bandgap reference, a conversion
block, a current source, and a comparator (Figure 1).
The device uses an external P-N junction as the tem-
perature-sensing element. It steers bias currents
through the external diode, measures the forward volt-
ages, and computes the temperature using a precision
chopper stabilized amplifier.
Resistance values of less than 100Ω in series with the
external sense junction will result in trip-point errors
< 1°C. The MAX6513 provides noise immunity by inte-
gration and oversampling of the diode voltage, but
good design practice includes routing the DXP and
DXN lines away from noise sources, such as high-
speed digital lines, switching regulators, inductors, and
transformers. The DXP and DXN traces should be
paired together and surrounded by ground plane
whenever possible.
In applications where the temperature changes rapidly,
the measured temperature will be approximately equal
to the average value of the temperature during the
measurement period.
The MAX6513 has an active-high CMOS output, and is
available with preset temperature thresholds from
+45°C to +125°C in 10°C increments.
GND
2
5
DXN
HYST
3
EP
4
TOVER
TDFN
Pin Description
PIN
1
2
3
NAME
V
DD
GND
HYST
FUNCTION
Power-Supply Input, +3.0V to
+5.5V. Bypass V
DD
to GND with
a 0.1μF capacitor.
Ground
Hysteresis Selection. Hysteresis
is 10°C for HYST = V
DD
, 5°C for
HYST = GND.
CMOS Active-High Output.
TOVER goes high when the
temperature exceeds the factory-
programmed temperature
threshold.
This pin connects to the
negative (cathode) terminal of
the external P-N sense junction.
DXN must be connected to GND.
This pin connects to the positive
(anode) terminal of the external
P-N sense junction.
Exposed Pad. Not internally
connected. Connect to GND or
leave unconnected.
4
TOVER
DXP
DXN
TEMPERATURE
CONVERSION
COMPAR-
ATOR
LATCH
TOVER
5
DXN
BANDGAP
6
DXP
VOLTAGE
REFERENCE
—
EP
Figure 1. Functional Block Diagram
4
_______________________________________________________________________________________
Low-Cost, Remote Temperature Switch
MAX6513
Table 1. Sensor Transistor Manufacturers
MANUFACTURER
Central Semiconductor (USA)
ON (USA)
Rohm Semiconductor (Japan)
Samsung (Korea)
Siemens (Germany)
Zetex (England)
MODEL NUMBER
CMPT3904
MMBT3904
SST3904
KST3904-TF
SMBT3904
FMMT3904CT-ND
TIME
TOVER
TRIP TEMPERATURE
TRIP TEMPERATURE HYSTERESIS
Note:
Transistors must be diode connected (base shorted to
collector).
Figure 2. Temperature Trip Threshold Hysteresis
Hysteresis Input
The HYST pin is a CMOS-compatible input that selects
hysteresis at either a high level (10°C for HYST = V
DD
)
or a low level (5°C for HYST = GND). Hysteresis pre-
vents the output from chattering when the temperature
is near the trip point. The HYST pin must not be left
unconnected.
The output asserts when the temperature exceeds the
trip point and deasserts when the temperature falls
back below the trip point minus the hysteresis. For
example, if the trip point is 105°C, the output will assert
at 105°C and will not deassert until temperature falls
below 105°C minus the hysteresis (e.g., 95°C if 10°C
hysteresis is chosen) (Figure 2).
Device Marking Codes
for TDFN Package
DEVICE
MAX6513TT045
MAX6513TT055
MAX6513TT065
MAX6513TT075
MAX6513TT085
MAX6513TT095
MAX6513TT105
MAX6513TT115
MAX6513TT125
CODE
+ACU
+ACV
+ACW
+ACX
+ACY
+ACZ
+ADA
+ADB
+ADC
TEMPERATURE TRIP
THRESHOLD (°C)
45
55
65
75
85
95
105
115
125
Applications Information
Remote-Diode Selection
To ensure best accuracy, use a good-quality diode-
connected transistor. Suggested devices are listed in
Table 1. Large power transistors are not recommend-
ed. Tight specifications for forward current gain indi-
cate the manufacturer has good process controls and
that the devices have consistent V
be
characteristics.
The MAX6513 can also measure the die temperature of
CPUs and other integrated circuits having on-board
temperature-sensing diodes. Use the monitor’s output
to reset the µP, assert an interrupt, activate a cooling
fan, or trigger an external alarm.
Package Information
For the latest package outline information and land patterns
(footprints), go to
www.maxim-ic.com/packages.
Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
6 TDFN-EP
PACKAGE
CODE
T633+2
OUTLINE
NO.
21-0137
LAND
PATTERN NO.
90-0058
Noise Filtering Capacitors
A quality ceramic capacitor must be connected across
the DXP/DXN inputs to maintain temperature threshold
accuracy by filtering out noise. The capacitor should
be located physically close to the DXP/DXN pins and
should typically have a value of 2200pF. Larger capaci-
tor values can cause temperature measurement errors.
A 50% variation from the recommended capacitor
value can cause up to ±1°C error.
_______________________________________________________________________________________
5
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