19-2457; Rev 2; 11/03
Precision, Low-Power, 6-Pin SOT23
Temperature Sensors and Voltage References
General Description
The MAX6610/MAX6611 are precise, low-power analog
temperature sensors combined with a precision voltage
reference. They are ideal for applications involving ana-
log-to-digital converters (ADCs), where the MAX6610/
MAX6611 provide the reference voltage for the ADC
and develop a temperature output voltage that is
scaled to provide convenient ADC output codes. An 8-
bit ADC’s LSB is equal to 1°C, while a 10-bit ADC’s LSB
corresponds to 0.25°C.
The MAX6610/MAX6611 are available in two versions.
The MAX6611 operates from a 4.5V to 5.5V power sup-
ply and has a 4.096V reference output. The MAX6610
operates from 3.0V to 5.5V and has a 2.560V reference
output. Power-supply current is less than 150µA (typ).
Both the MAX6610/MAX6611 are available in a 6-pin
SOT23 package and operate from -40°C to +125°C.
o
±1°C Accuracy
o
Low TC Reference (±10ppm, typ)
o
Temperature Output Scaled for ADCs
o
Integrated Reference Voltage Scaled for
Convenient ADC Bit Weights
o
No Calibration Required
o
Low Supply Current
o
Tiny 6-Pin SOT23 Package
o
Low-Current Shutdown Mode
Features
MAX6610/MAX6611
Applications
System Temperature Monitoring
Temperature Compensation
HVAC
Home Appliances
PART
Ordering Information
TEMP
RANGE
PIN-
V
REF
PACKAGE (V)
2.560
4.096
TOP
MARK
ABDO
ABOP
MAX6610AUT-T
-40°C to +125°C 6 SOT23-6
MAX6611AUT-T
-40°C to +125°C 6 SOT23-6
Pin Configuration
V
CC
Typical Application Circuit
TOP VIEW
V
CC
V
CC
1
6
GND
SHDN
GND
2
MAX6610
MAX6611
MAX6610
MAX6611
REF
TEMP
REF IN
ADC IN
1nF
GND
1nF
µC
5
REF
0.1µF
V
CC
SHDN
3
4
TEMP
GND
SOT23
GND
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Precision, Low-Power, 6-Pin SOT23
Temperature Sensors and Voltage References
MAX6610/MAX6611
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to GND
V
CC
........................................................................-0.3V to +6.0V
All Other Pins............................................. -0.3V to (V
CC
+ 0.3V)
Input Current ...................................................................... 20mA
Output Current ....................................................................20mA
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C) ........695.7mW
Operating Temperature Range (T
MIN
, T
MAX
) ....-40°C to +125°C
ESD Protection (all pins, Human Body Model) ..................2000V
Storage Temperature Range ............................-65°C to +150°C
Junction Temperature ......................................................+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
(V
CC
= 3.0 to 5.5V (MAX6610), V
CC
= 4.5V to 5.5V (MAX6611), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 5.0V (MAX6611) and V
CC
= 3.3V (MAX6610), T
A
= +25°C.) (Note 1)
PARAMETER
Supply Current
SYMBOL
I
CC
SHDN
= 0
T
A
= +25°C
Temperature Sensor Error
T
A
= -10°C to +55°C (Note 2)
T
A
= -20°C to +85°C (Note 2)
T
A
= -40°C to +125°C (Note 2)
Temperature Sensor Output
Voltage
Temperature Sensor Nonlinearity
Temperature Sensor Output Slope
Temperature Sensor Supply
Sensitivity
Temperature Sensor Load
Regulation
Temperature Sensor Capacitive
Load
Temperature Sensor Long-Term
Stability
Reference Output Voltage
Voltage Reference Temperature
Coefficient
Voltage Reference Line
Regulation
Voltage Reference Load
Regulation
Voltage Reference Long-Term
Stability
∆V
OUT
/
∆I
OUT
∆V
OUT
/
time
Sourcing: 0
≤
I
OUT
≤
1mA
Sinking: -200µA
≤
I
OUT
≤
0
1000h at T
A
= +25°C
V
REF
V
TEMP
MAX6611, T
A
= 0°C
MAX6610, T
A
= 0°C
T
A
= -10°C to +80°C
MAX6611
MAX6610
3.0V
≤
V
CC
≤
5.5V for MAX6610 and 4.5V
≤
V
CC
≤
5.5V for MAX6611
Sourcing: 0
≤
I
OUT
≤
500µA
Sinking: -100µA
≤
I
OUT
≤
0
No sustained oscillations (Note 3)
T
A
= +50°C for 1000hr
MAX6611, T
A
= +25°C
MAX6610, T
A
= +25°C
T
A
= -40°C to +85°C
4.076
2.547
-50
-1
1
4
50
-1
-2.5
0
±0.1
4.096
2.560
±10
4.116
2.573
+50
+1
2
20
-2.5
-1.2
-2.4
-3.7
-5.0
1.200
0.750
1
16
10
0.5
+1
+5
0.2
CONDITIONS
Outputs unloaded
MIN
TYP
150
0.2
MAX
250
1
+1.2
+2.4
+3.7
+5.0
V
°C
mV/°C
°C/V
°C/mA
µF
°C
V
ppm/°C
mV/V
Ω
ppm
°C
UNITS
µA
2
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Precision, Low-Power, 6-Pin SOT23
Temperature Sensors and Voltage References
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0 to 5.5V (MAX6610), V
CC
= 4.5V to 5.5V (MAX6611), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 5.0V (MAX6611) and V
CC
= 3.3V (MAX6610), T
A
= +25°C.) (Note 1)
PARAMETER
Voltage Reference Output Noise
Turn-On Settling Time
(V
CC
to REF)
Turn-On Settling Time
(V
CC
to TEMP)
Turn-On Settling Time
(SHDN to REF)
Turn-On Settling Time
(SHDN to TEMP)
LOGIC INPUT (SHDN)
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Leakage
V
IH
V
IL
I
LEAK
SHDN
= 5V, V
CC
= 5V
SHDN
= 0V, V
CC
= 5V
10
0.1
V
CC
-
0.5
0.5
25
1
V
V
µA
SYMBOL
CONDITIONS
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
V
CC
= 0 to 5V step, C
LOAD
= 50pF,
V
REF
= 0.1% of final value
V
CC
= 0 to 5V step, C
LOAD
= 50pF,
V
TEMP
= 1°C of final value
SHDN
= 0 to 5V step, C
LOAD
= 50pF,
V
REF
= 0.1% of final value
SHDN
= 0 to 5V step, C
LOAD
= 50pF,
V
TEMP
= 1°C of final value
MIN
TYP
100
100
300
500
300
500
MAX
UNITS
µV
P-P
µV
P-P
µs
µs
µs
µs
MAX6610/MAX6611
Note 1:
All parameters tested at room temperature. Values through temperature are guaranteed by design.
Note 2:
Guaranteed to 4 sigma.
Note 3:
Guaranteed by design.
Typical Operating Characteristics
(V
CC
= 5V, I
OUT
= 0V, T
A
= +25°C, unless otherwise specified.)
MAX6610
TEMPERATURE VOLTAGE
vs. TEMPERATURE
MAX6610 toc01
REFERENCE VOLTAGE ERROR
vs. TEMPERATURE
MAX6610 toc02
SUPPLY CURRENT vs. SUPPLY VOLTAGE
180
160
SUPPLY CURRENT (
m
A)
140
120
100
80
60
40
T
A
= +25
°
C
T
A
= -40
°
C
T
A
= +100
°
C
MAX6610 toc03
2.0
1.8
TEMPERATURE VOLTAGE (V)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0.10
REFERENCE VOLTAGE ERROR (%)
0.09
0.08
0.07
0.06
0.05
0.04
0.03
200
20
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
SUPPLY VOLTAGE (V)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (
°
C)
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Precision, Low-Power, 6-Pin SOT23
Temperature Sensors and Voltage References
MAX6610/MAX6611
Pin Description
PIN
1
2
3
NAME
V
CC
GND
SHDN
FUNCTION
Supply Voltage Input. Bypass to GND
with a 0.1µF capacitor.
Ground
Logic Level Shutdown Input (Active
Low). Driving
SHDN
with a logic low
turns off internal circuitry to reduce
supply current to 1µA (max).
Temperature Output Pin. Voltage at
TEMP varies linearly with temperature.
Reference Voltage Output
Must be connected to pin 2.
Temperature Sensor
The MAX6610/MAX6611 TEMP output provides an ana-
log output voltage that is a linear function of its die tem-
perature as defined by:
V
TEMP
= 1.2V + (T°C
✕
16mV/°C) for the MAX6611
and
V
TEMP
= 0.75V + (T°C
✕
10mV/°C) for the MAX6610
The slope of the output voltage is V
REF
/256 per °C
(16mV/°C for the MAX6611 and 10mV/°C for the
MAX6610). There is a +75°C offset on the temperature
output (The MAX6611’s output is 1.2V and, the
MAX6610’s output is 0.75V) at 0°C. The temperature error
is less than 1.2°C at T
A
= +25°C, less than ±3.8°C from
T
A
= -20°C to +85°C, and only ±5°C for T
A
= -40°C to
+125°C.
4
5
6
TEMP
REF
GND
Detailed Description
The MAX6610/MAX6611 combine a temperature sensor
with a low-power voltage reference. The reference volt-
age and temperature sensor gain give convenient LSB
weights when used with an ADC.
For example, when an 8-bit ADC is used with the
MAX6610/MAX6611, an LSB is equivalent to 1°C and a
10-bit ADC LSB is equivalent to 0.25°C.
The reference output features a proprietary tempera-
ture-coefficient, curvature-correction circuit and laser-
trimmed thin-film resistors that result in a low
temperature coefficient (50ppm/°C max) and initial
accuracy of ±0.5% max. The maximum supply current
is 250µA during normal operation and 1µA max during
shutdown. The supply voltage range is 3.0V to 5.5V for
the MAX6610 and 4.5V to 5.5V for the MAX6611.
Shutdown
The MAX6610/MAX6611 are equipped with a shutdown
feature that, when driven low, shuts down all internal cir-
cuitry and reduces supply current to 1µA (max). When in
shutdown, REF is pulled to GND through a 150kΩ resis-
tor and TEMP goes to a high-impedance state. For nor-
mal operation, connect
SHDN
to V
CC
.
Applications Information
Output/Load Capacitance
The MAX6610/MAX6611 TEMP output can drive capac-
itive loads up to 0.2µF. The MAX6610/MAX6611 REF
output can drive capacitive loads up to 1µF. Devices in
this family do not require an output capacitance for
dynamic stability. However, in applications where the
load or the supply can experience step changes, an
output capacitor within the specified range reduces the
amount of overshoot (or undershoot) and assists the
circuit’s transient response. Many applications do not
need an external capacitor, and this family can offer a
significant advantage in these applications when board
space is critical.
Voltage Reference
The MAX6610/MAX6611 REF output provides a voltage
reference for ADCs or other system subcircuits. REF is
capable of driving loads of up to 1mA. An output
capacitor can be as large as 1µF.
The voltage reference provides scaled ADC conver-
sions with bit weights that are in convenient units.
For the MAX6610 (2.56V REF output), an 8-bit ADC
yields 10mV/bit or 2.5mV/bit for a 10-bit ADC. The
MAX6611 (4.096V REF output) yields 16mV/bit for an 8-
bit ADC or 4mV/bit for a 10-bit ADC.
Supply Current
The quiescent supply current of the MAX6610/
MAX6611 is typically 150µA and is virtually indepen-
dent of the supply voltage. Unlike shunt-mode refer-
ences, the load current of series-mode references is
drawn from the supply voltage only when required, so
supply current is not wasted and efficiency is maxi-
mized over the entire supply voltage range. This
improved efficiency can help reduce power dissipation
and extend battery life.
4
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Precision, Low-Power, 6-Pin SOT23
Temperature Sensors and Voltage References
Sensing Circuit Board and
Ambient Temperatures
Temperature sensor ICs, like the MAX6610/MAX6611
that sense their own die temperatures, must be mount-
ed on, or close to, the object whose temperature they
are intended to measure. Because there is a good ther-
mal path between the package’s metal leads and the
IC die, the MAX6610/MAX6611 can accurately measure
the temperature of the circuit board to which it is sol-
dered. If the sensor is intended to measure the temper-
ature of a heat-generating 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 maximizes 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 MAX6610/MAX6611, like
all temperature sensors in plastic packages, are less
sensitive to the temperature of the surrounding air than
to the temperature of the leads. They can be success-
fully 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 is operated at cold temperatures
where condensation can occur.
Self-Heating
The MAX6610/MAX6611 are low-power circuits and are
intended to drive light loads. As a result, the tempera-
ture rise due to power dissipation on the die is insignifi-
cant under normal conditions.
For example, assume that the MAX6611 is operating
from a 5V supply at +50°C (V
TEMP
= 2V) and that the
temperature output is driving a 100kΩ load (I
TEMP
=
20µA). Also assume that the voltage reference is dri-
ving a 500µA load and the worst-case quiescent supply
current is used. In the 6-pin SOT23 package, the die
temperature increases above the ambient by 0.2°C.
Next, assume TEMP and REF are driving their maxi-
mum loads (I
TEMP
= 500µA and I
REF
= 1mA) and V
CC
= 5V, and T
A
= +50°C (V
TEMP
= 2V). Here, the die tem-
perature increases above the ambient by 0.4°C.
A first order for self-heating effects can be estimated
from temperature and reference load currents and the
previous supply voltage.
MAX6610/MAX6611
Chip Information
TRANSISTOR COUNT: 1346
PROCESS: BiCMOS
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