- 250 µA (typ.) Continuous Temperature
Conversion Mode
- 1 µA (max.) Shutdown Mode
• Power Saving One-Shot Temperature
Measurement
• Industry Standard 8-Pin MSOP Package
• Space Saving 8-Pin DFN (3x3 mm) Package
Typical Applications
• Personal Computers and Servers
• Hard Disk Drives and Other PC Peripherals
• Entertainment Systems
• Office Equipment
• Datacom Equipment
• Mobile Phones
• General Purpose Temperature Monitoring
Package Types
MSOP
1
DFN
NC
SCK
CE
GND
NC
CE
SCK
GND
1
2
3
4
TC72
2
3
4
TC72
8
7
6
5
V
DD
NC
SDI
SDO
8
7
6
5SDI
V
DD
NC
SDO
TC72
ce
General Description
The TC72 is a digital temperature sensor capable of
reading temperatures from -55°C to +125°C. This sensor features a serial interface that allows communication with a host controller or other peripherals. The
TC72 interface is compatible with the SPI protocol. The
TC72 does not require any additional external components. However, it is recommended that a decoupling
capacitor of 0.01 µF to 0.1 µF be provided between the
V
and GND pins.
DD
The TC72 can be used either in a Continuous Temperature Conversion mode or a One-Shot Conversion
mode. The Continuous Conversion mode measures
the temperature approximately every 150 ms and
stores the data in the temperature registers. In contrast, the One-Shot mode performs a single temperature measurement and returns to the power saving
shutdown mode.
The TC72 features high temperature accuracy, easeof-use and is the ideal solution for implementing thermal management in a variety of systems. The device is
available in both 8-pin MSOP and 8-pin DFN spacesaving packages. The TC72 also features a shutdown
mode for low power operation.
Storage temperature .......................... -65°C to +150°C
Ambient temp. with power applied ..... -55°C to +125°C
Junction Temperature ........................................ 150°C
ESD protection on all pins:
Human Body Model (HBM)............................. > 4 kV
Man Machine Model (MM).............................> 400V
Latch-Up Current at each pin ........................ ±200 mA
Maximum Power Dissipation........................... 250 mW
†Notice: Stresses above t hose listed under "Maximum
Ratings" may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operation listings of this specification is not implied. Exposure
to maximum rating conditions for extended periods may affect
device reliability.
†
+0.3V
DD
DC CHARACTERISTICS
PIN FUNCTION TABLE
NameFunction
NCNo Internal Connection
CEChip Enable Input, the device is selected
when this input is high
SCKSerial Clock Input
GNDGround
SDOSerial Data Output
SDISerial Data Input
NCNo Internal Connection
V
DD
Power Supply
Electrical Specifications: Unless otherwise noted, all parameters apply at VDD = 2.65V to 5.5V, TA = -55°C to +125 °C.
ParametersSymMinTypMaxUnitsConditions
Power Supply
Operating Voltage RangeV
Operating Current:
Normal Mode, ADC Active
Shut-Down Supply CurrentI
Temperature Sensor and Analog-to-Digital Converter
Temperature Accuracy
(Note 1)
Resolution—10—BitsNote 4
ADC Conversion Timet
Digital Input / Output
High Level Input VoltageV
Low Level Input VoltageV
High Level Output VoltageV
Low Level Output VoltageV
Input Resist anceR
Pin CapacitanceC
Note 1: The TC72-2.8MXX, TC72-3.3MXX and TC72-5.0MXX will operate from a supply voltage of 2.65V to 5.5V. However, the
TC72-2.8MXX, TC72-3.3MXX and TC72-5.0MXX are tested and specified at the nominal operating voltages of 2.8V,
3.3V and 5.0V respectively. As V
Figure 2-5 and Figure 2-6.
2: Measured with a load of C
3: All time measurements are measured with respect to the 50% point of the signal, except for the SCK rise and fall times.
The rise and fall times are defined as the 10% to 90% transition time.
4: Resolution = Temperature Range/No. of Bits = (+127°C – -128°C) / (2
DD
I
DD-CON
SHD
T
ACY
CONV
IH
IL
OH
OL
IN
IN
C
OUT
= 50 pF on the SDO output pin of the TC72.
L
2.65—5.5VNote 1
—250400µAContinuous temp. conversion mode
(Shutdown Bit = ‘0’)
—0.11.0µAShutdown Mode (Shutdown Bit = ‘1’)
-2.0—+2.0°C-40°C < TA < +85°C
-3.0—+3.0-55°C < T
—150200ms
0.7 V
——0.2 V
0.7 V
——0.2 V
1.0——MΩ
—15—pF
—50—
varies from the nominal operating value, the accuracy may be degraded. Refer to
DD
——V
DD
DD
——VIOH = 1 mA
DD
DD
10
) = 256/1024 = 0.25°C/Bit
V
VIOL = 4 mA
< +125°C
A
2002 Microchip Technology Inc.DS21743A-page 3
TC72
DC CHARACTERISTICS (CONTINUED)
Electrical Specifications: Unless otherwise noted, all parameters apply at VDD = 2.65V to 5.5V, TA = -55°C to +125 °C.
Note 1: The TC72-2.8MXX, TC72-3.3MXX and TC72-5.0MXX will operate from a supply voltage of 2.65V to 5.5V. However, the
TC72-2.8MXX, TC72-3.3MXX and TC72-5.0MXX are tested and specified at the nominal operating voltages of 2.8V,
3.3V and 5.0V respectively. As V
Figure 2-5 and Figure 2-6.
2: Measured with a load of C
3: All time measurements are measured with respect to the 50% point of the signal, except for the SCK rise and fall times.
= 50 pF on the SDO output pin of the TC72.
L
The rise and fall times are defined as the 10% to 90% transition time.
4: Resolution = Temperature Range/No. of Bits = (+127°C – -128°C) / (2
DC—7.5MHz
65——ns
65——ns
400——ns
——55ns
——40ns
35——ns
35——ns
100——ns
——200ns
——200ns
400——ns
—206—°C/W
—60.5—°C/W
varies from the nominal operating value, the accuracy may be degraded. Refer to
DD
10
) = 256/1024 = 0.25°C/Bit
DS21743A-page 4 2002 Microchip Technology Inc.
SPI READ DATA TRANSFER
(CP = 0, data shifted on rising edge of SCK, data clocked on falling edge of SCK, A7 = 0)
CE
1/f
t
CC
CLK
SCK
t
CCH
t
CWH
TC72
SDI
SDO
t
DC
A7
HIGH Z
t
CDH
MSb
t
t
R
F
A0
LSb
t
t
CH
CDD
D7
t
CL
MSb
SPI WRITE DATA TRANSFER
(CP = 0, data shifted on rising edge of SCK, data clocked on falling edge of SCK, A7 = 1)
CE
1/f
t
CC
CLK
SCK
t
t
R
F
t
t
DC
CDH
t
t
CL
CH
t
CCH
D0
t
CWH
LSb
t
CDZ
HIGH Z
SDI
A7 = 1
Note:
MSbLSbMSbLSb
The timing diagram is drawn with CP = 0. The
A0
D7D0
TC72
also functions with CP = 1;
however, the edges of SCK are reversed as defined in Table 3-3 and Figure 3-2.
FIGURE 1-1:Serial Port Timing Diagrams.
2002 Microchip Technology Inc.DS21743A-page 5
TC72
2.0TYPICAL PERFORMANCE CURVES
Note:The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, all parameters apply at V
3.5
3
2.5
2
1.5
Mean
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
Temperature Error (°C)
-3
-3.5
-55-255356595125
Upper Specification Limit
Mean + 3V
Mean - 3V
Lower Specification Limit
Reference Temperature (°C)
FIGURE 2-1:Accuracy vs. Temperature
(TC72-X.XMXX).
260
TC72-X.XMXX
250
TA = +25°C
240
230
220
210
Supply Current (µA)
200
2.53.03.54.04.55.05.5
TA = +125°C
TA = -55°C
Supply Voltage (V)
= 2.65V to 5.5V, TA = -55°C to +125°C.
DD
0.20
0.15
TC72-5.0MXX
= 5.0V
V
DD
0.10
0.05
Shutdown Current (µA)
0.00
-55-255356595125
TC72-5.0MXX
V
DD
Temperature (°C)
= 2.8V
TC72-3.3MXX
= 3.3V
V
DD
FIGURE 2-4:Shutdown Current vs.
Temperature.
0.4
TC72-2.8MXX
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
Temperature Change (°C)
-0.4
2.62.72.82.93.0
T
A
TA = +25°C
= +85°C
TA = -25°C
Supply Voltage (V)
FIGURE 2-2:Supply Current vs. Supply
Voltage.
400
350
TC72-5.0MXX
= 5.0V
V
DD
300
250
200
150
100
Supply Current (uA)
50
0
-55-255 356595125
TC72-2.8MXX
= 2.8V
V
DD
Temperature (°C)
TC72-3.3MXX
= 3.3V
V
DD
FIGURE 2-3:Supply Current vs.
Temperature.
FIGURE 2-5:Temperature Accuracy vs.
Supply Voltage (TC72-2.8MXX).
1.0
TC72-5.0MXX
0.8
0.6
0.4
0.2
TA = +85°C
0.0
-0.2
-0.4
-0.6
-0.8
Temperature Change (°C)
-1.0
4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5
TA = +25°C
TA = -25°C
Supply Voltage (V)
FIGURE 2-6:Temperature Accuracy vs.
Supply Voltage (TC72-5.0MXX).
DS21743A-page 6 2002 Microchip Technology Inc.
TC72
Note: Unless otherwise indicated, all parameters apply at V
50
45
40
35
30
25
20
15
10
5
0
Percentage of Occurances (%)
-3
-2.5-2-1.5-1-0.5
Temperature Error (°C)
TC72-X.XMXX
Sample Size = 166
= -55°C
T
A
0
0.511.522.5
3
FIGURE 2-7:Histogram of Temperature
Accuracy at -55 Degrees C.
60
TC72-X.XMXX
Sample Size = 166
50
= -40°C
T
A
40
30
20
10
0
Percentage of Occurances (%)
-2 -1.5 -1 -0.500.511.52
Temperature Error (°C)
= 2.65V to 5.5V, TA = -55°C to +125°C.
DD
60
50
40
30
20
10
0
Percentage of Occurances (%)
-1.50
-1.25
-1.00
-0.75
-0.50
Temperature Error (°C)
TC72-X.XMXX
Sample Size = 166
T
A
0.00
0.25
-0.25
= +65°C
0.50
0.75
FIGURE 2-10:Histogram of Temperature
Accuracy at +65 Degrees C.
50
45
40
35
30
25
20
15
10
5
0
Percentage of Occurances (%)
-2 -1.5 -1 -0.500.511.52
Temperature Error (°C)
TC72-X.XMXX
Sample Size = 166
= +85°C
T
A
1.00
1.25
1.50
FIGURE 2-8:Histogram of Temperature
Accuracy at -40 Degrees C.
60
TC72-X.XMXX
50
Sample Size = 166
= +25°C
T
A
40
30
20
10
0
Percentage of Occurances (%)
0.00
0.25
0.50
0.75
1.00
1.25
-1.50
-1.25
-1.00
-0.75
-0.50
Temperature Error (°C)
-0.25
1.50
FIGURE 2-9:Histogram of Temperature
Accuracy at +25 Degrees C.
FIGURE 2-11:Histogram of Temperature
Accuracy at +85 Degrees C.
40
35
30
25
20
15
10
5
0
Percentage of Occurances (%)
-3
-2.5-2-1.5-1-0.5
Temperature Error (°C)
TC72-X.XMXX
Sample Size = 166
= +125°C
T
A
0
0.511.522.5
3
FIGURE 2-12:Histogram of Temperature
Accuracy at +125 Degrees C.
2002 Microchip Technology Inc.DS21743A-page 7
TC72
3.0FUNCTIONAL DESCRIPTION
The TC72 consists of a band-gap type temperature
sensor, a 10-bit Sigma Delta Analog-to-Digital Converter (ADC), an internal conversion oscillator and a
double buffer digital output port. The 10-bit ADC is
scaled from -128°C to +127°C; therefore, the resolution
is 0.25°C per bit. The ambient temperature operating
range of the TC72 is specified from -55°C to +125°C.
This device features a four-wire serial interface that is
fully compatible with the SPI specification and, therefore, allows simple communications with common
microcontrollers and processors. The TC72 can be
used either in a Continuous Temperature Conversion
mode or a One-Shot Conversion mode. The TC72 temperature measurements are performed in the background and, therefore, reading the temperature via the
serial I/O lines does not affect the measurement in
progress.
MSBLSB
0111 1101 / 0000 0000
The Continuous Conversion mode measures the temperature approximately every 150 ms and stores the
data in the temperature registers. The TC72 has an
internal clock generator that controls the automatic
temperature conversion sequence. The automatic temperature sampling operation is repeated indefinitely
until the TC72 is placed in a shutdown mode by a write
operation to the Control register. The TC72 will remain
in the shutdown mode until the shutdown bit in the
Control register is reset.
In contrast, the One-Shot mode performs a single temperature measurement and returns to the power-saving shut down mode. This mode is especially useful for
low power applications.
Output
Code
Te m p
+25°C
+0.25°C
MSBLSB
0001 1001 / 0000 0000
MSBLSB
0000 0000 / 0100 0000
MSBLSB
0000 00 00 / 0000 0000
-55°C
-25°C
Note:The ADC converter is scaled from -128°C to -127°C, but the operating range of the
TC72 is specified from -55°C to +125°C.
0°C
-0.125°C
MSBLSB
1111 1111 / 1100 0000
MSBLSB
1110 0111 / 0000 0000
MSBLSB
1100 1001 / 0000 0000
Tem p
+125°C
FIGURE 3-1:Temperature-To-Digital Transfer Function (Non-linear Scale).
DS21743A-page 8 2002 Microchip Technology Inc.
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