General Description
The MAX6511/MAX6512/MAX6513 are fully integrated,
remote temperature switches that use an external P-N
junction (typically a diode-connected transistor) as the
sensing element to measure the remote temperature.
These devices assert 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 (TA= -40°C to +85°C). Hysteresis is pin selectable to 5°C or 10°C.
The MAX6511 has an active-low CMOS output and the
MAX6513 has an active-high CMOS output. The
MAX6512 has an open-drain output. The output is
asserted when the temperature exceeds the threshold
value. The active-low open-drain output is intended to
interface with a microprocessor (µP) reset or interrupt
input. The active-high CMOS output can directly drive a
power FET to control a cooling fan.
The MAX6511/MAX6512/MAX6513 operate from a
+3.0V to +5.5V supply and typically consume 400µA of
supply current. They are available in a small 6-pin
SOT23 package.
________________________Applications
CPU Temperature Monitoring in High-Speed
Computers
Multichip Modules
Battery Packs
Temperature Control
Temperature Alarms
Fan Control
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-Low CMOS Output (MAX6511) or Open-
Drain Output for Overtemperature Alarm
(MAX6512) or Active-High Output (MAX6513) for
Direct Fan Control
♦ <100ms Response Time
♦ Accuracy
±3°C (T
REMOTE =
+45°C to +125°C, TA= -5°C to +55°C)
±5°C (T
REMOTE =
+45°C to +125°C, TA= -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 SOT23 Package
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
19-1819; Rev 0; 10/00
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
*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
MAX6511UT065-T describes a MAX6511 in a SOT23-6 package
with a +65°C threshold.
Typical Operating Circuit appears at end of data sheet.
TOP VIEW
16DXP
V
DD
GND
2
34
( ) ARE FOR MAX6513 SOT23 ONLY.
MAX6511
MAX6512
MAX6513
5 DXN
TOVER (TOVER)HYST
PART* TEMP. RANGE
M AX6 511EUT_ _ _ -T -40°C to +85°C 6 SOT23-6
M AX6 512EUT_ _ _ -T -40°C to +85°C 6 SOT23-6 Open-Drain
M AX6 513EUT_ _ _ -T -40°C to +85°C 6 SOT23-6
PINPACKAGE
OUTPUT
CMOS
(Active-Low)
CMOS
(Active-High)
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
DD
= +3.0V to +5.5V, CS= 2200pF, TA= -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)
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.
Note 1: T
REMOTE
refers to the temperature of the remote-sensing junction. TArefers to the temperature of the MAX6511/MAX6512/
MAX6513 package.
Note 2: All parameters are 100% production tested at T
A
= +25°C. Specifications over temperature limits are guaranteed by design.
Note 3: This parameter is guaranteed by design to ±3.5 sigma.
Supply Voltage (V
DD
) ...............................................-0.3V to +6V
DXP, DXN, HYST, TOVER (MAX6513),
TOVER (MAX6511/MAX6512) ................-0.3V to (V
DD
+ 0.3V)
TOVER (MAX6513), TOVER (MAX6511)
Output Current ....................................................-1mA/+50mA
DXN Input Current...................................................-1mA/+50mA
Current (all other pins)......................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23-6 (derate 9.1mW/°C above +70°C) ........727mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature
Vapor Phase (60s) .......................................................+215°C
Infrared (15s) ...............................................................+220°C
Supply Voltage Range V
Supply Current I
Temperature Threshold
Accuracy (Note 3)
Power-Supply Sensitivity for
Temperature Trip Point
Temperature Threshold
Hysteresis
Response Time 70 120 ms
Input Voltage High V
Input Voltage Low V
Output Voltage High V
Output Voltage Low V
Maximum DXP Source
Current
Minimum DXP Source
Current
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DD
DD
∆T
T
HYST
OH
OL
TA = -5°C to +55°C -3.0 +3.0
TH
TA = -40°C to +85°C -5.0 +5.0
HYST = V
HYST = V
IH
IL
MAX6511/MAX6513, I
I
0.4V ≤ V
DXN = GND
0.4V ≤ V
DXN = GND
3.0 5.5 V
400 600 µA
-0.6 °C/V
IL
IH
5
10
VDD -
0.2
0.2 V
V
= 1mA
OUT
= 1mA 0.2 V
OUT
≤ 2V,
DXP
≤ 2V,
DXP
DD
- 0.2
270 µA
9µA
°C
°C
V
V
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
_______________________________________________________________________________________ 3
Typical Operating Characteristics
(VDD= +3.3V, CS= 2200pF, TA= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. AMBIENT TEMPERATURE
440
420
400
380
360
SUPPLY CURRENT (µA)
340
320
300
-40 10-15 35 60 85
AMBIENT TEMPERATURE TA (°C)
(NOTE: SUPPLY CURRENT
INCLUDES EXTERNAL
DIODE-CONNECTED
TRANSISTOR)
MAX6511 toc01
TEMPERATURE TRIP THRESHOLD ERROR
vs. AMBIENT TEMPERATURE T
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
TEMPERATURE TRIP THRESHOLD ERROR (°C)
-1.6
-60 -40 -20 0 20 40 8060 100 120 140
AMBIENT TEMPERATURE TA (°C)
TEMPERATURE TRIP THRESHOLD ERROR
A
MAX6511 toc02
14
12
10
8
6
4
2
0
-2
TEMPERATURE TRIP THRESHOLD ERROR (°C)
-4
02010 30 40 50 60
CAPACITANCE
vs. C
S
CS CAPACITANCE (nF)
MAX6511 toc03
TEMPERATURE TRIP THRESHOLD ERROR
vs. SERIES RESISTANCE
1.0
0.5
0
-0.5
-1.0
-1.5
TEMPERATURE TRIP THRESHOLD ERROR (°C)
-2.0
0806020 40 100 120 140 160 180 200
SERIES RESISTANCE (Ω)
MAX6511 toc04
TEMPERATURE TRIP THRESHOLD
vs. SUPPLY VOLTAGE
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
-1.6
TEMPERATURE TRIP THRESHOLD ERROR (°C)
-1.8
3.0 4.03.5 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
MAX6511 toc05
Detailed Description
The MAX6511/MAX6512/MAX6513 fully integrated temperature switches incorporate a precision bandgap reference, a conversion block, a current source, and a
comparator (Figure 1). These devices use an external
P-N junction as the temperature-sensing element. They
steer bias currents through the external diode, measure
the forward voltages, and compute 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 MAX6511/MAX6512/MAX6513 provide noise
immunity by integration 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 MAX6512 has an active-low, open-drain output structure that can only sink current. The MAX6511 has an activelow CMOS output structure, and the MAX6513 has an
active-high CMOS output.
The MAX6511/MAX6512/MAX6513 are available with
preset temperature thresholds from +45°C to +125°C in
10°C increments.
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
4 _______________________________________________________________________________________
Pin Description
Figure 1. Functional Block Diagram
PIN
MAX6511
MAX6512
11V
2 2 GND Ground
3 3 HYST Hysteresis Selection. Hysteresis is 10°C for HYST = VDD, 5°C for HYST = GND.
4 — TOVER
— 4 TOVER
55DXN
6 6 DXP
MAX6513
NAME FUNCTION
DD
Power-Supply Input, +3.0V to +5.5V. Bypass VDD to GND with a 0.1µF
capacitor.
CMOS Active-Low Output (MAX6511) or Open-Drain Active-Low Output
(MAX6512). TOVER goes low when the temperature exceeds the factoryprogrammed temperature threshold. This pin can only sink current in the
MAX6512.
CMOS Active-High Output (MAX6513). 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.
BANDGAP
DXP
DXN
TEMPERATURE
CONVERSION
VOLTAGE
REFERENCE
COMPAR-
ATOR
LATCH
TOVER
Hysteresis Input
The HYST pin is a CMOS-compatible input that selects
hysteresis at either a high level (10°C for HYST = VDD)
or a low level (5°C for HYST = GND). Hysteresis prevents the output from chattering when the temperature
is near the trip point. The HYST pin must not float.
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).
Applications Information
Remote-Diode Selection
To ensure best accuracy, use a good-quality diodeconnected transistor. Suggested devices are listed in
Table 1. Large power transistors are not recommended. Tight specifications for forward current gain indi-
cate the manufacturer has good process controls and
that the devices have consistent V
be
characteristics.
The MAX6511/MAX6512/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.
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 capacitor values can cause temperature measurement errors.
A 50% variation from the recommended capacitor
value can cause up to ±1°C error.
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
_______________________________________________________________________________________ 5
Figure 2. Temperature Trip Threshold Hysteresis
Table 1. Sensor Transistor Manufacturers
Note: Transistors must be diode connected (base shorted to
collector).
MANUFACTURER MODEL NUMBER
Central Semiconductor (USA) CMPT3904
ON (USA) MMBT3904
Rohm Semiconductor (Japan) SST3904
Samsung (Korea) KST3904-TF
Siemens (Germany) SMBT3904
Zetex (England) FMMT3904CT-ND
TRIP TEMPERATURE
TRIP TEMPERATURE HYSTERESIS
TOVER (MAX6511)
TIME
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
6 _______________________________________________________________________________________
Typical Operating Circuit
Chip Topography
TRANSISTOR COUNT: 3300
Device Marking Codes for SOT23-6 Package
3.3V
V
DD
µP
C
DXP
S
DXN
HYST
MAX6511
DEVICE CODE
MAX6511UT045 AAOA 45
MAX6511UT055 AAOB 55
MAX6511UT065 AAOC 65
MAX6511UT075 AAOD 75
MAX6511UT085 AAOE 85
MAX6511UT095 AAOF 95
MAX6511UT105 AAOG 105
MAX6511UT115 AAOH 115
MAX6511UT125 AAOI 125
MAX6512UT045 AAOJ 45
MAX6512UT055 AAOK 55
MAX6512UT065 AAOL 65
MAX6512UT075 AAOM 75
MAX6512UT085 AAON 85
TEMPERATURE TRIP
THRESHOLD (°C)
DEVICE CODE
MAX6512UT095 AAOO 95
MAX6512UT105 AAOP 105
MAX6512UT115 AAOQ 115
MAX6512UT125 AAOR 125
MAX6513UT045 AAPD 45
MAX6513UT055 AAPE 55
MAX6513UT065 AAPF 65
MAX6513UT075 AAPG 75
MAX6513UT085 AAPH 85
MAX6513UT095 AAPI 95
MAX6513UT105 AAPJ 105
MAX6513UT115 AAPK 115
MAX6513UT125 AAPL 125
2µF
TOVER (TO MICROPROCESSOR FAN
CONTROLLER, SHUTDOWN, ETC.)
TEMPERATURE TRIP
THRESHOLD (°C)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX6511/MAX6512/MAX6513
Low-Cost, Remote SOT Temperature Switches
Package Information
6LSOT.EPS
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