MICROCHIP TC72 Technical data

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Digital Temperature Sensor with SPI™ Interfa

Features

• Temperature-to-Digital Converter

• SPI™ Compatible Interface

• 10-Bit Resolution (0.25°C/Bit)

• ±2°C (max.) Accuracy from -40°C to +85°C

• ±3°C (max.) Accuracy from -55°C to +125°C

• 2.65V to 5.5V Operating Range

• Low Power Consumption:

- 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

DFN

SCK

GND

SCK

GND

TC72

SDI

SDO

5SDI

SDO

TC72

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.

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.

Block Diagram

Internal

Diode

Temperature

Sensor

10-Bit

Sigma Delta

A/D Converter

Temperature

GND

TC72

Manufacturer ID Register

Serial

Port

Interface

Control

CE SCK

SDO SDI

 2002 Microchip Technology Inc. DS21743A-page 1

TC72

Typical Application

0.1µF

TC72

PICmicro

MCU

SDO

GND

SCK

AN0

SCK

SDI

SDOSDI

DS21743A-page 2  2002 Microchip Technology Inc.

TC72

1.0 ELECTRICAL

CHARACTERISTICS

1.1 Maximum Ratings

VDD........................................................................ 6.0V

All inputs and outputs w.r.t. GND ...-0.3V to V

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

DC CHARACTERISTICS

PIN FUNCTION TABLE

Name Function

NC No Internal Connection

CE Chip Enable Input, the device is selected

when this input is high

SCK Serial Clock Input

GND Ground

SDO Serial Data Output

SDI Serial Data Input

NC No Internal Connection

Power Supply

Electrical Specifications: Unless otherwise noted, all parameters apply at VDD = 2.65V to 5.5V, TA = -55°C to +125 °C.

Parameters Sym Min Typ Max Units Conditions

Power Supply

Operating Voltage Range V

Operating Current:

Normal Mode, ADC Active

Shut-Down Supply Current I

Temperature Sensor and Analog-to-Digital Converter

Temperature Accuracy (Note 1)

Resolution — 10 — Bits Note 4

ADC Conversion Time t

Digital Input / Output

High Level Input Voltage V

Low Level Input Voltage V

High Level Output Voltage V

Low Level Output Voltage V

Input Resist ance R

Pin Capacitance 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.

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-CON

SHD

ACY

CONV

OUT

= 50 pF on the SDO output pin of the TC72.

2.65 — 5.5 V Note 1

— 250 400 µA Continuous temp. conversion mode

(Shutdown Bit = ‘0’)

— 0.1 1.0 µA Shutdown 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

——V

——VIOH = 1 mA

) = 256/1024 = 0.25°C/Bit

VIOL = 4 mA

< +125°C

 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.

Parameters Sym Min Typ Max Units Conditions

Serial Port AC Timing (Note 2, 3)

Clock Frequency f

SCK Low Time t

SCK High Time t

CE to SCK Setup t

SCK to Data Out Valid t

CE to Output Tri-state t

SCK to Data Hold Time t

Data to SCK Set-up Time t

SCK to CE Hold Time t

SCK Rise Time t

SCK Fall Time t

CE Inactive Time t

CLK

CDD

CDZ

CDH

CCH

CWH

Thermal Package Resistance

Thermal Resistance, MSOP-8 θ Thermal Resistance, DFN-8 θ

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.

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 — 7.5 MHz

65 — — ns

400 — — ns

— — 55 ns

— — 40 ns

35 — — ns

100 — — ns

——200ns

400 — — ns

—206—°C/W

—60.5—°C/W

varies from the nominal operating value, the accuracy may be degraded. Refer to

) = 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)

1/f

CLK

SCK

CCH

CWH

TC72

SDI

SDO

HIGH Z

CDH

MSb

LSb

CDD

MSb

SPI WRITE DATA TRANSFER

(CP = 0, data shifted on rising edge of SCK, data clocked on falling edge of SCK, A7 = 1)

1/f

CLK

SCK

CDH

CCH

CWH

LSb

CDZ

HIGH Z

SDI

A7 = 1

Note:

MSb LSb MSb LSb

The timing diagram is drawn with CP = 0. The

D7 D0

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

2.0 TYPICAL 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

0.5 0

-0.5

-1

-1.5

-2

-2.5

Temperature Error (°C)

-3

-3.5

-55 -25 5 35 65 95 125

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

2.5 3.0 3.5 4.0 4.5 5.0 5.5

TA = +125°C

TA = -55°C

Supply Voltage (V)

= 2.65V to 5.5V, TA = -55°C to +125°C.

0.20

0.15 TC72-5.0MXX

= 5.0V

0.10

0.05

Shutdown Current (µA)

0.00

-55 -25 5 35 65 95 125

TC72-5.0MXX V

Temperature (°C)

= 2.8V

TC72-3.3MXX

= 3.3V

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

2.6 2.7 2.8 2.9 3.0

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

300

250

200

150

100

Supply Current (uA)

-55-255 356595125

TC72-2.8MXX

= 2.8V

Temperature (°C)

TC72-3.3MXX

= 3.3V

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

0.511.522.5

FIGURE 2-7: Histogram of Temperature Accuracy at -55 Degrees C.

TC72-X.XMXX Sample Size = 166

= -40°C

Percentage of Occurances (%)

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Temperature Error (°C)

= 2.65V to 5.5V, TA = -55°C to +125°C.

Percentage of Occurances (%)

-1.50

-1.25

-1.00

-0.75

-0.50

Temperature Error (°C)

TC72-X.XMXX Sample Size = 166 T

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 -0.5 0 0.5 1 1.5 2

Temperature Error (°C)

TC72-X.XMXX Sample Size = 166

= +85°C

1.00

1.25

1.50

FIGURE 2-8: Histogram of Temperature Accuracy at -40 Degrees C.

TC72-X.XMXX

Sample Size = 166

= +25°C

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.

Percentage of Occurances (%)

-3

-2.5-2-1.5-1-0.5

Temperature Error (°C)

TC72-X.XMXX Sample Size = 166

= +125°C

0.511.522.5

FIGURE 2-12: Histogram of Temperature Accuracy at +125 Degrees C.

 2002 Microchip Technology Inc. DS21743A-page 7

TC72

3.0 FUNCTIONAL 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.

MSB LSB

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

MSB LSB

0001 1001 / 0000 0000

MSB LSB

0000 0000 / 0100 0000

MSB LSB

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

MSB LSB

1111 1111 / 1100 0000

MSB LSB

1110 0111 / 0000 0000

MSB LSB

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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