TMP03/TMP04

REV. A

–15–

Monitoring Electronic Equipment

The TMP03 are ideal for monitoring the thermal environment

within electronic equipment. For example, the surface-mounted

package will accurately reflect the exact thermal conditions which

affect nearby integrated circuits. The TO-92 package, on the

other hand, can be mounted above the surface of the board, to

measure the temperature of the air flowing over the board.

The TMP03 and TMP04 measure and convert the temperature

at the surface of their own semiconductor chip. When the TMP03

are used to measure the temperature of a nearby heat source,

the thermal impedance between the heat source and the TMP03

must be considered. Often, a thermocouple or other tempera-

ture sensor is used to measure the temperature of the source

TMP04

GND

T1

T2

CLR

B

A

Q

Q

5V

5V

0.1 F

74HC4538

GND

OUT

1

10

74HC373

VCC

LE

D1 D2 D3 D4

D5 D6 D7 D8

Q1 Q2 Q3 Q4

Q5 Q6 Q7 Q8

2 5 6 9

12 15 16 19

3 4 7 8

13 14 17 18

20

11

5V

3

1

2

3

1

2

5

4

74HC08

1

74HC4520 #1

VCC

CLK

Q0 Q1 Q2 Q3

Q0 Q1 Q2 Q3

3 4 5 6

11 12 13 14

9

7

815

16

5V

10

EN

EN

2

CLK GND

RESET RESET

10

3

13

8

12

11

74HC373

VCC

LE

D1 D2 D3 D4

D5 D6 D7 D8

Q1 Q2 Q3 Q4

Q5 Q6 Q7 Q8

2 5 6 9

12 15 16 19

3 4 7 8

13 14 17 18

20

11

5V

74HC373

VCC

LE

D1 D2 D3 D4

D5 D6 D7 D8

Q1 Q2 Q3 Q4

Q5 Q6 Q7 Q8

2 5 6 9

12 15 16 19

3 4 7 8

13 14 17 18

20

11

5V

74HC373

VCC

LE

D1 D2 D3 D4

D5 D6 D7 D8

Q1 Q2 Q3 Q4

Q5 Q6 Q7 Q8

2 5 6 9

12 15 16 19

3 4 7 8

13 14 17 18

20

11

5V

74HC4520 #2

VCC

Q0 Q1 Q2 Q3

Q0 Q1 Q2 Q3

3456

11 12 13 14

17

9

15

16

5V

10

EN

EN

2

CLK GND RESET RESET

1MHZ

CLOCK

6

T1 DATA (MICROSECONDS)

T2 DATA (MICROSECONDS)

GND

T1

T2

CLR

B

A

Q

Q

5V

5V

10 F

GND

V+

5V

20pF 3.9k

9

15

14

16

6

7

5

8

4

1k

20pF

74HC86

10pF

10k

4

5

6

NC

NC

CLK

8

GND

OUT

1

10

GND

OUT

1

10

GND

OUT

1

10

Figure 12. A Hardware Interface for the TMP04

while the TMP03 temperature is monitored by measuring T1

and T2. Once the thermal impedance is determined, the tem-

perature of the heat source can be inferred from the TMP03

output.

One example of using the TMP04 to monitor a high power

dissipation microprocessor or other IC is shown in Figure 13.

The TMP04, in a surface mount package, is mounted directly

beneath the microprocessor’s pin grid array (PGA) package. In

a typical application, the TMP04’s output would be connected

to an ASIC where the pulsewidth would be measured (see the

Hardware Interface section of this data sheet for a typical inter-

face schematic). The TMP04 pulse output provides a significant