MAXIM MAX6605_08

19-1840; Rev 2; 11/08
Low-Power Analog Temperature Sensor
in SC70 Package
Features
The MAX6605 precision, low-power, analog output temperature sensor is available in a 5-pin SC70 package.
The device has a +2.7V to +5.5V supply voltage range
and 10µA supply current over the -55°C to +125°C temperature range. For the -40°C to +105°C temperature
range, the supply voltage can go as low as +2.4V.
Accuracy is ±0.75°C at TA = +25°C and ±3°C from 0°C
to +70°C.
o Low Current Consumption (10μA max)
o Small SC70 Package
o Accurate (±0.75°C at TA = +25°C)
o Optimized to Drive Large Capacitive Loads
Ordering Information
The MAX6605 output voltage is dependent on its die
temperature and has a slope of 11.9mV/°C and an offset of 744mV at 0°C. The output typically shows only
+0.4°C of nonlinearity over the -20°C to +85°C temperature range.
PART
TEMP RANGE
MAX6605MXK-T
PIN-PACKAGE
-55°C to +125°C
5 SC70-5
T = Tape and reel.
________________________Applications
Pin Configuration
Cellular Phones
Battery Packs
TOP VIEW
GPS Equipment
Digital Cameras
VCC 1
A 2
5
GND
4
B
MAX6605
OUT 3
SC70
Typical Application Circuit
VCC
VCC
VDD
B
MAX6605
CS = 0.1μF
A
SHDN
VCC
MAX1106
OUT
GND
CPU
CONVST
I/O
REFOUT
SCLK
I/O
REFIN
DOUT
I/O
IN+
1nF
IN–
GND
GND
GND
________________________________________________________________ Maxim Integrated Products
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.
1
MAX6605
General Description
MAX6605
Low-Power Analog Temperature Sensor
in SC70 Package
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.3V to +6V
OUT, A, B to GND ......................................-0.3V to (VCC + 0.3V)
ESD Protection (Human Body Model) ............................> 2000V
Current into Any Pin ............................................................10mA
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (TA = +70°C)
5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............245mW
Operating Temperature Range .........................-55°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°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
(VCC = +2.7V to +5.5V, CL = 1nF, TA = -55°C to +125°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TA = +25°C
Temperature Error
VOUT = 0.744 + (0.0119 × T°C) +
(1.604 × 10-6 × T2)V (Note 2)
Supply Voltage
MAX
TA = -0°C to +70°C
-3.0
+3.0
TA = -20°C to +85°C
-3.8
+3.8
TA = -40°C to +100°C
-5.0
+5.0
TA = -55°C to +125°C
-5.8
+5.8
TA = -55°C to +125°C
2.7
5.5
TA = -40°C to +105°C
2.4
5.5
VCC = +3.3V
VCC
TYP
V
IQ
No load
4.5
Output Voltage
VOUT
TA = 0°C
744
mV
Nonlinearity
TA = -20°C to +85°C
0.4
°C
Sensor Gain (Average Slope)
TA = -40°C to +100°C
11.1
Capacitive Load
Required for stability
1
11.9
10
°C
Supply Current
Load Regulation
12.7
20
TA = -55°C, IOUT = -10µA to +10µA
20
_______________________________________________________________________________________
µA
mV/°C
nF
TA = -20°C to +125°C, IOUT = -20µA to +20µA
Note 1: All parameters are measured at TA = +25°C. Specifications over temperature range are guaranteed by design.
Note 2: Error (expressed in °C) is defined as the difference between the calculated and measured values of output voltage.
Guaranteed by design to 5 sigma.
2
UNITS
±0.75
m°C/µA
Low-Power Analog Temperature Sensor
in SC70 Package
TEMPERATURE ERROR (°C)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
-55 -35 -15
5
25
45
65
85 105 125
MAX6605 toc03
2
1
0
-55 -35 -15
5
25
45
65
0
85 105 125
1
2
3
4
5
SUPPLY VOLTAGE (V)
SUPPLY CURRENT
vs. TEMPERATURE
OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
STEP-RESPONSE FROM +25°C TO +100°C
(FLUORINERT BATH)
5
VCC = +3.3V
4
VCC = +2.4V
2
1.055
MAX6605 toc06
MAX6605 toc04
1.060
OUTPUT VOLTAGE (V)
SUPPLY CURRENT (μA)
3
TEMPERATURE (°C)
VCC = +5V
3
TA = +25°C
4
TEMPERATURE (°C)
7
6
5
MAX6605 toc05
OUTPUT VOLTAGE (V)
1.8
1.7
1.5
1.3
1.1
0.9
0.7
0.5
0.3
0.1
-0.1
-0.3
-0.5
-0.7
-0.9
-1.1
-1.3
SUPPLY CURRENT (μA)
2.0
6
MAX6605 toc02
MAX6605 toc01
2.2
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
TEMPERATURE ERROR
vs. TEMPERATURE
OUTPUT VOLTAGE vs. TEMPERATURE
1.050
1.045
OUT
500mV/div
1.040
TA = +25°C
1.035
1.030
1
1.025
1.020
0
-55 -35 -15
5
25
45
65
TEMPERATURE (°C)
85 105 125
0
0
1
2
3
4
5
6
1s/div
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
3
MAX6605
Typical Operating Characteristics
(VCC = +3.3V, CS = 0.1µF, CL = 1nF, unless otherwise noted.)
Low-Power Analog Temperature Sensor
in SC70 Package
MAX6605
Pin Description
PIN
NAME
FUNCTION
1
VCC
Supply Input. Decouple with a 0.1µF
capacitor to GND.
2
A
Must be connected to GND.
3
OUT
Temperature Sensor Output,
CL ≥ 1nF
4
B
Must be connected to VCC.
5
GND
Ground
Detailed Description
The MAX6605 analog output temperature sensor’s output voltage is a linear function of its die temperature.
The slope of the output voltage is 11.9mV/°C, and there
is a 744mV offset at 0°C to allow measurement of negative temperatures. The MAX6605 has three terminals:
VCC, GND, and OUT. The maximum supply current is
10µA, and the supply voltage range is from +2.4V to
+5.5V for the -40°C to +105°C temperature range and
+2.7V to +5.5V for the -55°C to +125°C temperature
range. The temperature error is <1°C at TA = +25°C,
<3.8°C from TA = -20°C to +85°C, and <5.8°C from TA
= -55°C to +125°C.
Nonlinearity
The benefit of silicon analog temperature sensors over
thermistors is linearity over extended temperatures. The
nonlinearity of the MAX6605 is typically 0.4°C over the
-20°C to +85°C temperature range.
Transfer Function
The temperature-to-voltage transfer function has an
approximately linear positive slope and can be
described by the equation:
Applications Information
Sensing Circuit Board and
Ambient Temperatures
Temperature sensor ICs like the MAX6605 that sense
their own die temperatures must be mounted on, or
close to, the object whose temperature they are intended to measure. Because there is a good thermal path
between the SC70 package’s metal leads and the IC
die, the MAX6605 can accurately measure the temperature of the circuit board to which it is soldered. If the
sensor is intended to measure the temperature of a heatgenerating component on the circuit board, it should be
mounted as close as possible to that component and
should share supply and ground traces (if they are not
noisy) with that component where possible. This will maximize the heat transfer from the component to the sensor.
The thermal path between the plastic package and the
die is not as good as the path through the leads, so the
MAX6605, like all temperature sensors in plastic packages, is less sensitive to the temperature of the surrounding air than it is to the temperature of its leads. It can be
successfully used to sense ambient temperature if the circuit board is designed to track the ambient temperature.
As with any IC, the wiring and circuits must be kept insulated and dry to avoid leakage and corrosion, especially if
the part will be operated at cold temperatures where condensation can occur.
The thermal resistance junction to ambient (θJA) is the
parameter used to calculate the rise of a device junction
temperature (TJ) due to its power dissipation. For the
MAX6605, use the following equation to calculate the rise
in die temperature:
TJ = TA + θJA ((VCC x IQ) + (VCC - VOUT) IOUT)
T (°C) = (VOUT - 744mV) / 11.9mV/°C
The MAX6605 is a very-low-power temperature sensor
and is intended to drive very light loads. As a result, the
temperature rise due to power dissipation on the die is
insignificant under normal conditions. For example,
assume that the MAX6605 is operating from a +3V supply at +21.6°C (VOUT = 1V) and is driving a 100kΩ load
(IOUT = 10µA). In the 5-pin SC70 package, the die temperature will increase above the ambient by:
To account for the small amount of curvature in the
transfer function, use the equation below to obtain a
more accurate temperature reading:
TJ - TA = θJA ((VCC x IQ) + (VCC - VOUT) IOUT) =
324°C/W x ((3V x 10µA) + (3V - 1V) x 10µA) = 0.0162°C
VOUT = 0.744V + 0.0119V/°C T(°C) +
Therefore, the error caused by power dissipation will be
negligible.
VOUT = 744mV + (T 11.9mV/°C)
where T is the MAX6605’s die temperature in °C.
Therefore:
1.604 10-6 V/°C2 (T(°C))2
4
_______________________________________________________________________________________
Low-Power Analog Temperature Sensor
in SC70 Package
TRANSISTOR COUNT: 573
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
5 SC70
X5-1
21-0076
_______________________________________________________________________________________
5
MAX6605
Chip Information
Capacitive Loads
The MAX6605 can drive unlimited load capacitance.
For stable operation load capacitance should be >1nF.
MAX6605
Low-Power Analog Temperature Sensor
in SC70 Package
Revision History
PAGES
CHANGED
REVISION
NUMBER
REVISION
DATE
0
10/00
Initial release
—
1
8/04
—
—
2
11/08
Corrected the parameter unit for VOUT in the Transfer Function section.
4
DESCRIPTION
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.
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is a registered trademark of Maxim Integrated Products, Inc.