combined with a programmable overtemperature alarm
and a 3-wire (SPI-compatible) serial interface in a single
package. It converts its die temperature into digital values
using an internal analog-to-digital converter (ADC). The
temperature data is stored in a temperature register as a
13-bit word, which allows 0.0625°C resolution. The tem-
perature data is readable at any time through the serial
interface. The operating temperature range is -55°C to
+150°C.
The MAX6662 provides two programmable watchdog
interrupt outputs.
ALERT
is used for lower temperature
warning functions, while
OT
is used for higher tempera-
ture-critical functions, such as power-supply shutdown.
The MAX6662 features a shutdown mode that saves
power by disabling everything except the serial interface.
The temperature sensor is available in an 8-pin SO pack-
age.
Features
●
12-Bit + Sign, 0.0625°C Resolution
●
Accuracy
±1°C max (+30°C to +50°C)
±1.6°C max (0°C to +70°C)
±2.5°C max (-20°C to +85°C)
±2.5 typ (+150°C)
●
Extended Temperature Measurement Range
-55°C to +150°C
●
Low Average Supply Current, 125µA (typ)
●
Shutdown Mode to Minimize Power Consumption in
Portable Applications
●
Two Programmable Temperature Fault Outputs
●
Switchable Fault Queue to Eliminate False Tripping
in Noisy Environments
Applications
●
HVAC
●
Refrigeration
●
Test Equipment
Ordering Information
PART
MAX6662MSA
TEMP. RANGE
-55°C to +150°C
PIN-PACKAGE
8 SO
Typical Operating Circuit
V
CC
= +3V TO +5.5V
0.1µF
10kΩ
V
CC
HEAT
SOURCES
OT
ALERT
MAX6662
SIO
SCLK
CS
10kΩ
Pin Configuration
TOP VIEW
SCLK 1
CS 2
8
V
CC
NC
ALERT
OT
MAX6662
7
6
5
SYSTEM
CONTROLLER
SIO
3
GND 4
SO
19-2121; Rev 1; 4/14
MAX6662
12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
Absolute Maximum Ratings
(All voltages are referenced to GND.)
V
CC
..........................................................................-0.3V to +6V
ALERT,
OT. .............................................................-0.3V to +6V
SIO, SCLK,
CS
......................................... -0.3V to (V
CC
+ 0.3V)
SIO Current ...................................................... -10mA to +50mA
Continuous Current into Any Pin (except NC)....................10mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C).................471mW
Operating Temperature Range (Note 1) ......... -55°C to +150°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) ................................. +300°C
Note 1:
The MAX6662 is not recommended to operate above +125°C for an extended period of time.
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
= +3V to +5.5V, T
A
= -55°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C and V
CC
= +3.3V.)
PARAMETER
SYMBOL
CONDITIONS
+30°C ≤ T
A
≤ +50°C, V
CC
= +3.3V
0°C ≤ T
A
≤ +70°C, V
CC
= +3.3V
Accuracy
-20°C ≤ T
A
≤ +85°C, V
CC
= +3.3V
-40°C ≤ T
A
≤ +100°C, V
CC
= +3.3V
-55°C ≤ T
A
≤ +125°C, V
CC
= +3.3V
T
A
≤ +150°C, V
CC
= +3.3V
Power-Supply Rejection Ratio
Resolution
Supply Voltage Range
Average Operating Current
Peak Operating Current (Note 2)
Shutdown Supply Current
Power-On-Reset Threshold
Power-On-Reset Threshold Hysteresis
Conversion Time
Temperature Update Frequency
Input Low Voltage
Input High Voltage
Input/Output Leakage Current
Input Capacitance
Output Low Sink Current
Output High Voltage
Output Low Voltage
t
CONV
V
POR
V
CC
V
CC
= +5.5V
V
CC
= +3.0V
V
CC
= +5.5V
V
C
C = +3.0V
V
CC
= +5.5V
V
CC
= +3.0V
3.0
150
125
300
300
8
4
2.0
90
0.25
2
0.8
0.7 V
CC
V
IN
= GND or V
CC
ALERT, OT, V
OL
= 0.6V
I
SIO
= 1.6mA source
I
SIO
= 1.6mA sink
-5
5
3
V
CC
- 0.4
0.4
+5
600
500
22
15
2.5
PSRR
MIN
-1.0
-1.6
-2.5
-3.0
-4.0
TYP
±0.4
±0.7
±1.0
±1.2
±1.5
±2.5
0.2
0.0625
5.5
0.5
°C/V
°C
V
µA
µA
µA
V
mV
s
Hz
V
V
µA
pF
mA
V
V
MAX
+1.0
+1.6
+2.5
+3.0
+4.0
°C
UNITS
TEMPERATURE TO DIGITAL-CONVERTER CHARACTERISTICS
SERIAL INTERFACE (SIO, SCLK,
CS, ALERT, OT)
V
IL
V
IH
I
LEAK
C
in
I
OL
V
OH
V
OL
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Maxim Integrated
│
2
MAX6662
12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
Electrical Characteristics continued)
(V
CC
= +3V to +5.5V, T
A
= -55°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C and V
CC
= +3.3V.)
PARAMETER
SERIAL INTERFACE TIMING
Serial Clock Frequency
SCLK High Pulse Width
SCLK Low Pulse Width
CS High Pulse Width
SCLK Fall to Output Data Valid
CS Fall to SCLK Rise
CS Rise to Output Disable
CS to SCLK Hold Time
SIO to SCLK Setup Time
SIO to SCLK Hold Time
Output Fall Time
f
SCLK
t
CH
t
CL
t
CSW
t
DO
t
CSS
t
TR
t
CSH
t
DS
t
DH
t
F
C
LOAD
= 100pF
0
100
0
10
C
LOAD
= 100pF
100
100
200
200
200
100
2.5
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 2:
Peak operating current measured during conversion.
Typical Operating Characteristics
(V
CC
= +3V, T
A
= +25°C, unless otherwise noted.)
TEMPERATURE ERROR
VS. TEMPERATURE
PERCENTAGE OF SAMPLES (%)
MAX6662 toc01
MAX6662 toc02
TEMPERATURE ERROR (
°
C)
2
1
0
-1
-2
-3
V
CC
= +5.0V
V
CC
= +3.3V
V
CC
= +3.0V
80
70
60
50
40
30
20
10
SUPPLY CURRENT (µA)
NOTE:
DEVICES
TRIMMED AT
T
A
= +30
°
C
200 SAMPLES
T
A
= +30
°
C
AVERAGE OVER 2
180
V
CC
= +5.0V
160
140
120
V
CC
= +3.0V
100
V
CC
= +3.3V
-50 -30 -10 10 30 50 70 90 110 130 150
0
-0.45-0.35 -0.25 -0.15 0.05 0.15 0.25 0.35 0.45
TEMPERATURE ERROR (°C)
-50
0
50
100
150
TEMPERATURE (°C)
TEMPERATURE (°C)
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Maxim Integrated
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3
MAX6662 toc03
3
90
TEMPERATURE
ERROR DISTRIBTUTION
200
VS.
TEMPERATURE
SUPPLY CURRENT
MAX6662
12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
Typical Operating Characteristics
(continued)
(V
CC
= +3V, T
A
= +25°C, unless otherwise noted.)
SHUTDOWN CURRENT
VS.
TEMPERATURE
MAX6662 toc04
12
SHUTDOWN CURRENT (µA)
10
V
CC
= +5.0V
8
6
4
2
0
V
CC
= +3.3V
V
CC
= +3.0V
-50
0
50
100
150
TEMPERATURE (°C)
Pin Description
PIN
1
2
3
4
5
6
7
8
NAME
SCLK
CS
SIO
GND
OT
ALERT
NC
V
CC
Serial-Clock Input
Chip Select Input. Set low to enable the serial interface for data input/output.
Serial-Data Input/Output. Bidirectional data input and output for serial interface.
Ground
Overtemperature Output. Open-drain output requires a pullup resistor to V
CC
.
Alert Output. Open-drain output requires a pullup resistor to V
CC
.
No Connection. Do not make a connection to this pin.
Supply Voltage Input. Bypass to GND with a 0.1µF capacitor as close to V
CC
as possible.
FUNCTION
Detailed Description
The MAX6662 continuously converts its die temperature
into a digital value using its integrated ADC. Temperature
data is updated twice a second. The resulting data is
readable at any time through the SPI-compatible serial
interface.
Figure 1 shows the simplified functional diagram of the
MAX6662. Its internal current sources force 100µA and
10µA currents through a diode (diode-connected tran-
sistor), while the integrating ADC measures the voltage
difference. The difference in voltage corresponds to the
die temperature. The result is stored in the temperature
register. The control logic unit compares the temperature
and the temperature limit settings stored in the registers
to determine whether a fault condition has occurred.
Temperature Fault Alert
The
ALERT
is an open-drain active-low (default, also
programmable active-high) output used to alert the sys-
tem to temperature faults.
ALERT
can be programmed
to operate in either one of two modes: comparator or
interrupt mode.
Interrupt Mode
In the interrupt mode, the MAX6662
ALERT
pin asserts
an alarm for an undertemperature (T
LOW
) fault, as well
as for an overtemperature (T
HIGH
) fault. Once either fault
has occurred, it remains active indefinitely, regardless of
condition.
ALERT
is unconditionally deasserted (even if
temperature is still out of limits) by reading the tempera-
ture register.
ALERT
only asserts again if the temperature
crosses the hysteresis, thereby corresponding to the fault
(T
LOW
or T
HIGH
) that initially set the
ALERT.
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Maxim Integrated
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4
MAX6662
12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
V
CC
OT
12 -BIT
+ SIGN
ADC
ALERT
TEMPERATURE T
LOW
T
HIGH
T
MAX
T
HYST
CONFIGURATION
SIO
SCLK
CS
SERIAL INTERFACE
Figure 1. MAX6662 Simplified Functional Diagram
For example: If T
HIGH
is set to 100°C and T
HYST
is set
to 20°C,
ALERT
does not assert until temperature
exceeds 100°C. If the temperature is then read through
the serial interface,
ALERT
deasserts.
ALERT
asserts
again when temperature is less than 80°C (Figure 2).
Overtemperature Alert
Comparator Mode
In the comparator mode,
ALERT
is asserted when
temperature exceeds the value in the T
HIGH
register,
or is lower than the value in the T
LOW
register.
ALERT
deasserts when temperature is less than T
HIGH
- T
HYST
or greater than T
LOW
+ T
HYST
. Reading the registers
does not deassert
ALERT.
For example: If T
HIGH
is set to 100°C and T
LOW
is set
to 80°C,
ALERT
does not assert until temperature
exceeds 100°C, or is below 80°C. Then,
ALERT
only
deasserts if temperature is less than T
HIGH
- T
HYST
or
greater than T
LOW
+ T
HYST
.
OT
operates only in comparator mode. The
OT
pin is
asserted when the temperature exceeds T
MAX
, and
deasserted when the temperature drops below
T
MAX
- T
HYST
. A read operation does not reset
OT.
OT
is an open-drain active-low (default) output, but can
FPGA/CPLD
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