Analog Devices TMP03, TMP04 Datasheet

a

Serial Digital Output Thermometers

TMP03/TMP04*

FEATURES
Low Cost 3-Pin Package
Modulated Serial Digital Output
Proportional to Temperature
±1.58C Accuracy (typ) from –258C to +1008C
Specified –408C to +1008C, Operation to 1508C
Power Consumption 6.5 mW Max at 5 V
Flexible Open-Collector Output on TMP03
CMOS/TTL Compatible Output on TMP04
Low Voltage Operation (4.5 V to 7 V)

APPLICATIONS
Isolated Sensors
Environmental Control Systems
Computer Thermal Monitoring
Thermal Protection
Industrial Process Control
Power System Monitors

GENERAL DESCRIPTION

The TMP03/TMP04 is a monolithic temperature detector that
generates a modulated serial digital output that varies in direct
proportion to the temperature of the device. An onboard sensor
generates a voltage precisely proportional to absolute temperature
which is compared to an internal voltage reference and input to a
precision digital modulator. The ratiometric encoding format of
the serial digital output is independent of the clock drift errors
common to most serial modulation techniques such as voltage­to-frequency converters. Overall accuracy is ± 1.5°C (typical)
from –25°C to +100°C, with excellent transducer linearity. The
digital output of the TMP04 is CMOS/TTL compatible, and is
easily interfaced to the serial inputs of most popular micro­processors. The open-collector output of the TMP03 is capable
of sinking 5 mA. The TMP03 is best suited for systems requiring
isolated circuits utilizing optocouplers or isolation transformers.

The TMP03 and TMP04 are specified for operation at supply
voltages from 4.5 V to 7 V. Operating from +5 V, supply current
(unloaded) is less than 1.3 mA.

The TMP03/TMP04 are rated for operation over the –40°C to
+100°C temperature range in the low cost TO-92, SO-8, and
TSSOP-8 surface mount packages. Operation extends to
+150°C with reduced accuracy.

(continued on page 4)

FUNCTIONAL BLOCK DIAGRAM

TMP03/04

TEMPERATURE

SENSOR

VPTAT

DIGITAL

MODULATOR

123

D

OUT

V+ GND

V

REF

PACKAGE TYPES AVAILABLE

TO-92

TMP03/04

1 2 3

D

V+ GND

OUT

BOTTOM VIEW

(Not to Scale)

SO-8 and RU-8 (TSSOP)

D

1

OUT

V+

2

GND

3

NC

4

NC = NO CONNECT

TMP03/04

TOP VIEW

(Not to Scale)

NC

8

NC

7

NC

6

NC

5

*Patent pending.

REV. 0

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

© Analog Devices, Inc., 1995

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] Fax: [phone]

TMP03/TMP04–SPECIFICATIONS

TMP03F

(V+ = +5 V, –408C ≤ TA ≤ 1008C unless otherwise noted)

Parameter Symbol Conditions Min Typ Max Units

ACCURACY

Temperature Error T

= +25°C 1.0 3.0 °C

A

–25°C < T
–40°C < T

< +100°C

A

< –25°C

A

1

1

1.5 4.0 °C

2.0 5.0 °C
Temperature Linearity 0.5 °C
Long-Term Stability 1000 Hours at +125°C 0.5 °C
Nominal Mark-Space Ratio T1/T2 T

= 0°C 58.8 %

A

Nominal T1 Pulse Width T1 10 ms
Power Supply Rejection Ratio PSRR Over Rated Supply 0.7 1.2 °C/V

T

= +25°C

A

OUTPUTS

Output Low Voltage V
Output Low Voltage V

Output Low Voltage V

Digital Output Capacitance C
Fall Time t

OL
OL

OL

OUT

HL

I

= 1.6 mA 0.2 V

SINK

I

= 5 mA 2 V

SINK

0°C < T
I

SINK

–40°C < T

< +100°C

A

= 4 mA 2 V

< 0°C

A

(Note 2) 15 pF
See Test Load 150 ns

Device Turn-On Time 20 ms

POWER SUPPLY

Supply Range V+ 4.5 7 V
Supply Current I

NOTES

1

Maximum deviation from output transfer function over specified temperature range.

2

Guaranteed but not tested.

Specifications subject to change without notice.

SY

Unloaded 0.9 1.3 mA

Test Load

10 kΩ to +5 V Supply, 100 pF to Ground

TMP04F

(V+ = +5 V, –408C ≤ TA ≤ +1008C unless otherwise noted)

Parameter Symbol Conditions Min Typ Max Units

ACCURACY

Temperature Error T

= +25°C 1.0 3.0 °C

A

–25°C < T
–40°C < T

< +100°C

A

< –25°C

A

1

1

1.5 4.0 °C

2.0 5.0 °C
Temperature Linearity 0.5 °C
Long-Term Stability 1000 Hours at +125°C 0.5 °C
Nominal Mark-Space Ratio T1/T2 T

= 0°C 58.8 %

A

Nominal T1 Pulse Width T1 10 ms
Power Supply Rejection Ratio PSRR Over Rated Supply 0.7 1.2 °C/V

T

= +25°C

A

OUTPUTS

Output High Voltage V
Output Low Voltage V
Digital Output Capacitance C
Fall Time t
Rise Time t

OH
OL

OUT
HL
LH

I

= 800 µA V+ –0.4 V

OH

I

= 800 µA 0.4 V

OL

(Note 2) 15 pF
See Test Load 200 ns
See Test Load 160 ns

Device Turn-On Time 20 ms

POWER SUPPLY

Supply Range V+ 4.5 7 V
Supply Current I

NOTES

1

Maximum deviation from output transfer function over specified temperature range.

2

Guaranteed but not tested.

Specifications subject to change without notice.

SY

Unloaded 0.9 1.3 mA

Test Load

100 pF to Ground

–2–

REV. 0

TMP03/TMP04

WARNING!

ESD SENSITIVE DEVICE

WAFER TEST LIMITS

(V+ = +5 V, GND = 0 V, TA = +258C, unless otherwise noted)

Parameter Symbol Conditions Min Typ Max Units

ACCURACY

Temperature Error T

= +25°C

A

1

3.0 °C

Power Supply Rejection Ratio PSRR Over Rated Supply 1.2 °C/V

OUTPUTS

Output High Voltage, TMP04 V
Output Low Voltage, TMP04 V
Output Low Voltage, TMP03 V

OH
OL
OL

I

= 800 µA V+ – 0.4 V

OH

I

= 800 µA 0.4 V

OL

I

= 1.6 mA 0.2 V

SINK

POWER SUPPLY

Supply Range V+ 4.5 7 V
Supply Current I

NOTES
Electrical tests are performed at wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed
for standard product dice. Consult factory to negotiate specifications based on dice lot qualification through sample lot assembly and testing.

1

Maximum deviation from ratiometric output transfer function over specified temperature range.

SY

ABSOLUTE MAXIMUM RATINGS*

Unloaded 1.3 mA

DICE CHARACTERISTICS

Maximum Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . +9 V

Maximum Output Current (TMP03 D
Maximum Output Current (TMP04 D

) . . . . . . . . . 50 mA

OUT

) . . . . . . . . . 10 mA

OUT

Maximum Open-Collector Output Voltage (TMP03) . . +18 V

Operating Temperature Range . . . . . . . . . . . –55°C to +150°C

Dice Junction Temperature . . . . . . . . . . . . . . . . . . . . +175°C

Storage Temperature Range . . . . . . . . . . . . –65°C to +160°C

Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . +300°C

*CAUTION

1

Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only and functional
operation at or above this specification is not implied. Exposure to the above
maximum rating conditions for extended periods may affect device reliability.

2

Digital inputs and outputs are protected, however, permanent damage may occur
on unprotected units from high-energy electrostatic fields. Keep units in conduc­tive foam or packaging at all times until ready to use. Use proper antistatic handling
procedures.

3

Remove power before inserting or removing units from their sockets.

Package Type Θ

TO-92 (T9) 162
SO-8 (S) 158
TSSOP (RU) 240

NOTE

1

ΘJA is specified for device in socket (worst case conditions).

JA

1
1
1

Θ

JC

Units

120 °C/W
43 °C/W
43 °C/W

Model at +258C Range Package

Die Size 0.050 × 0.060 inch, 3,000 sq. mils

( 1.27 × 1.52 mm, 1.93 sq. mm)

For additional DICE ordering information, refer to databook.

ORDERING GUIDE

Accuracy Temperature

TMP03FT9 ±3.0 XIND TO-92
TMP03FS ±3.0 XIND SO-8
TMP03FRU ±3.0 XIND TSSOP-8
TMP03GBC ±3.0 +25°C Die
TMP04FT9 ±3.0 XIND TO-92
TMP04FS ±3.0 XIND SO-8
TMP04FRU ±3.0 XIND TSSOP-8
TMP04GBC ±3.0 +25°C Die

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the TMP03/TMP04 features proprietary ESD protection circuitry, permanent damage
may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.

REV. 0

–3–

TMP03/TMP04

T1

T2

(continued from page 1)

The TMP03/TMP04 is a powerful, complete temperature
measurement system with digital output, on a single chip. The
onboard temperature sensor follows in the footsteps of the
TMP01 low power programmable temperature controller,
offering excellent accuracy and linearity over the entire rated
temperature range without correction or calibration by the user.

The sensor output is digitized by a first-order sigma-delta
modulator, also known as the “charge balance” type analog-to­digital converter. (See Figure 1.) This type of converter utilizes
time-domain oversampling and a high accuracy comparator to
deliver 12 bits of effective accuracy in an extremely compact
circuit.

∑∆

MODULATOR

VOLTAGE REF

&

VPTAT

CLOCK

GENERATOR

INTEGRATOR

∫

1-BIT

DAC

COMPARATOR

DIGITAL

FILTER

TMP03/04
OUT
(SINGLE-BIT)

neatly avoids major error sources common to other modulation
techniques, as it is clock-independent.

Output Encoding

Accurate sampling of an analog signal requires precise spacing
of the sampling interval in order to maintain an accurate
representation of the signal in the time domain. This dictates a
master clock between the digitizer and the signal processor. In
the case of compact, cost-effective data acquisition systems, the
addition of a buffered, high speed clock line can represent a
significant burden on the overall system design. Alternatively,
the addition of an onboard clock circuit with the appropriate
accuracy and drift performance to an integrated circuit can add
significant cost. The modulation and encoding techniques
utilized in the TMP03/TMP04 avoid this problem and allow the
overall circuit to fit into a compact, three-pin package. To
achieve this, a simple, compact onboard clock and an
oversampling digitizer that is insensitive to sampling rate
variations are used. Most importantly, the digitized signal is
encoded into a ratiometric format in which the exact frequency
of the TMP03/TMP04’s clock is irrelevant, and the effects of
clock variations are effectively canceled upon decoding by the
digital filter.

The output of the TMP03/TMP04 is a square wave with a
nominal frequency of 35 Hz (±20%) at +25°C. The output
format is readily decoded by the user as follows:

Figure 1. TMP03/TMP04 Block Diagram Showing
First-Order Sigma-Delta Modulator

Basically, the sigma-delta modulator consists of an input sampler,
a summing network, an integrator, a comparator, and a 1-bit
DAC. Similar to the voltage-to-frequency converter, this
architecture creates in effect a negative feedback loop whose
intent is to minimize the integrator output by changing the duty
cycle of the comparator output in response to input voltage
changes. The comparator samples the output of the integrator at
a much higher rate than the input sampling frequency, called
oversampling. This spreads the quantization noise over a much
wider band than that of the input signal, improving overall noise
performance and increasing accuracy.

The modulated output of the comparator is encoded using a
circuit technique (patent pending) which results in a serial
digital signal with a mark-space ratio format that is easily
decoded by any microprocessor into either degrees centigrade or
degrees Fahrenheit values, and readily transmitted or modulated
over a single wire. Most importantly, this encoding method

Figure 2. TMP03/TMP04 Output Format

Temperature (°C) =

Temperature (°F) =

235 −

455 −



400 ×T1






720 ×T1




T 2

T 2











The time periods T1 (high period) and T2 (low period) are
values easily read by a microprocessor timer/counter port, with
the above calculations performed in software. Since both
periods are obtained consecutively, using the same clock,
performing the division indicated in the above formulas results
in a ratiometric value that is independent of the exact frequency
of, or drift in, either the originating clock of the TMP03/TMP04 or
the user’s counting clock.

–4–

REV. 0

TMP03/TMP04

Table I. Counter Size and Clock Frequency Effects on Quantization Error

Maximum Maximum Maximum Quantization Quantization
Count Available Temp Required Frequency Error (+258C) Error (+778F)

4096 +125°C 94 kHz 0.284°C 0.512°F
8192 +125°C 188 kHz 0.142°C 0.256°F
16384 +125°C 376 kHz 0.071°C 0.128°F

Optimizing Counter Characteristics

Counter resolution, clock rate, and the resultant temperature
decode error that occurs using a counter scheme may be
determined from the following calculations:

1. T1 is nominally 10 ms, and compared to T2 is relatively
insensitive to temperature changes. A useful worst-case
assumption is that T1 will never exceed 12 ms over the
specified temperature range.

T1 max = 12 ms
Substituting this value for T1 in the formula, temperature

(°C) = 235 – ([T1/T2] × 400), yields a maximum value of
T2 of 44 ms at 125°C. Rearranging the formula allows the
maximum value of T2 to be calculated at any maximum
operating temperature:

T2 (Temp) = (T1max × 400)/(235 – Temp) in seconds

2. We now need to calculate the maximum clock frequency we
can apply to the gated counter so it will not overflow during
T2 time measurement. The maximum frequency is calculated
using:

Frequency (max) = Counter Size/ (T2 at maximum
temperature)

Substituting in the equation using a 12-bit counter gives,
Fmax = 4096/44 ms . 94 kHz.

3. Now we can calculate the temperature resolution, or
quantization error, provided by the counter at the chosen
clock frequency and temperature of interest. Again, using a
12-bit counter being clocked at 90 kHz (to allow for ~5%
temperature over-range), the temperature resolution at
+25°C is calculated from:

Quantization Error (

°

C) = 400 × ([Count1/Count2] –

[Count1 – 1]/[Count2 + 1])
Quantization Error (

°

F) = 720 × ([Count1/Count2] –

[Count1 – 1]/[Count2 + 1])

where, Count1 = T1max × Frequency, and Count2 =
T2 (Temp) × Frequency. At +25°C this gives a resolution of
better than 0.3°C. Note that the temperature resolution
calculated from these equations improves as temperature
increases. Higher temperature resolution will be obtained by
employing larger counters as shown in Table I. The internal
quantization error of the TMP03/TMP04 sets a theoretical
minimum resolution of approximately 0.1°C at +25°C.

Self-Heating Effects

The temperature measurement accuracy of the TMP03/TMP04
may be degraded in some applications due to self-heating.
Errors introduced are from the quiescent dissipation, and power
dissipated by the digital output. The magnitude of these
temperature errors is dependent on the thermal conductivity of
the TMP03/TMP04 package, the mounting technique, and
effects of airflow. Static dissipation in the TMP03/TMP04 is

typically 4.5 mW operating at 5 V with no load. In the TO-92
package mounted in free air, this accounts for a temperature
increase due to self-heating of

∆T = P

× ΘJA = 4.5 mW × 162°C/W = 0.73°C (1.3°F)

DISS

For a free-standing surface-mount TSSOP package, the
temperature increase due to self-heating would be

∆T = P

× ΘJA = 4.5 mW × 240°C/W = 1.08°C (1.9°F)

DISS

In addition, power is dissipated by the digital output which is
capable of sinking 800 µA continuous (TMP04). Under full
load, the output may dissipate

P

= 0.6 V

()

DISS

0.8 mA

()






T1+T2



T2




For example with T2 = 20 ms and T1 = 10 ms, the power
dissipation due to the digital output is approximately 0.32 mW
with a 0.8 mA load. In a free-standing TSSOP package this
accounts for a temperature increase due to output self-heating
of

∆T = P

× ΘJA = 0.32 mW × 240°C/W = 0.08°C (0.14°F)

DISS

This temperature increase adds directly to that from the
quiescent dissipation and affects the accuracy of the TMP03/
TMP04 relative to the true ambient temperature. Alternatively,
when the same package has been bonded to a large plate or
other thermal mass (effectively a large heatsink) to measure its
temperature, the total self-heating error would be reduced to
approximately

∆T = P

Calibration

× ΘJC = (4.5 mW + 0.32 mW) × 43°C/W = 0.21°C (0.37°F)

DISS

The TMP03 and TMP04 are laser-trimmed for accuracy and
linearity during manufacture and, in most cases, no further
adjustments are required. However, some improvement in
performance can be gained by additional system calibration. To
perform a single-point calibration at room temperature, measure
the TMP03/TMP04 output, record the actual measurement
temperature, and modify the offset constant (normally 235; see
the Output Encoding section) as follows:

Offset Constant = 235 + (T

OBSERVED

– T

TMP03OUTPUT

)

A more complicated two-point calibration is also possible. This
involves measuring the TMP03/TMP04 output at two temp­eratures, Temp1 and Temp2, and modifying the slope constant
(normally 400) as follows:

Slope Constant =




T 2@Temp1



Temp2 −Temp1

T1@Temp1





T1@Temp 2

−





T 2@Temp2










where T1 and T2 are the output high and output low times,
respectively.

REV. 0

–5–

SUPPLY VOLTAGE – Volts

1.05

0.97

4.5 7.5

NORMALIZED OUTPUT FREQUENCY

5 5.5 6 6.5 7

1.01

1.00

0.99

0.98

1.04

1.02

1.03

TA = +25°C
R

LOAD

= 10kΩ

TA = +25°C
V

DD

= +5V

C

LOAD

= 100pF

R

LOAD

= 1kΩ

TIME SCALE = 1µs/DIV

VOLTAGE SCALE = 2V/DIV

Ch 1 +Width
Wfm does not

cross ref

∞

s

Ch 1 –Width
Wfm does not

cross ref

∞

s

Ch 1 Fall

No valid

edge

∞

s

Running:

50.0MS/s

Sample

(T)

Ch 1 Rise

500ns

TMP03/TMP04–Typical Performance Characteristics

70

60

50

40

30

20

OUTPUT FREQUENCY – Hz

10

0
–75 175–25

V+ = +5V

= 10kΩ

R

LOAD

25 75 125

TEMPERATURE – °C

Figure 3. Output Frequency vs. Temperature

45

40

35

VS = +5V
R

LOAD

= 10kΩ

30

25

20

TIME – ms

15

10

5

0

–75 175–25

25 75 125

TEMPERATURE – °C

Figure 4. T1 and T2 Times vs. Temperature

Running:
200MS/s ET

VOLTAGE SCALE = 2V/DIV

Figure 5. TMP03 Output Fall Time at +25°C

Sample

(T)

TIME SCALE = 250ns/DIV

TA = +25°C

= +5V

V

DD

C

= 100pF

LOAD

= 1kΩ

R

LOAD

T2

T1

Ch 1 +Width
Wfm does not

cross ref

Ch 1 –Width
Wfm does not

cross ref

∞

s

∞

s

Ch 1 Rise

∞

s

No valid

edge

Ch 1 Fall

209.6ns

Figure 6. Normalized Output Frequency vs. Supply Voltage

Figure 7. TMP03 Output Rise Time at +25°C

Running:

50.0MS/s

VOLTAGE SCALE – 2V/DIV

TA = +125°C
V

Sample

= +5V

DD

TIME SCALE – 1µs/DIV

(T)

C
R

LOAD
LOAD

= 100pF

= 1kΩ

Ch 1 +Width

∞

s
Wfm does not
cross ref

Ch 1 –Width

∞

s
Wfm does not
cross ref

Ch 1 Rise

538ns

Ch 1 Fall

∞

s

No valid

edge

Figure 8. TMP03 Output Rise Time at +125°C

–6–

REV. 0

TMP03/TMP04

TA = +25°C
V

DD

= +5V

C

LOAD

= 100pF

R

LOAD

= 0

TIME SCALE – 250ns/DIV

VOLTAGE SCALE – 2V/DIV

Ch 1 +Width
Wfm does not

cross ref

∞

s

Ch 1 –Width
Wfm does not

cross ref

∞

s

Ch 1 Fall

No valid

edge

∞

s

Running:
200MS/s ET

Sample

(T)

Ch 1 Rise

110.6ns

TA = +125°C
V

DD

= +5V

C

LOAD

= 100pF

R

LOAD

= 0

TIME SCALE – 250ns/DIV

VOLTAGE SCALE – 2V/DIV

Ch 1 +Width
Wfm does not

cross ref

∞

s

Ch 1 –Width
Wfm does not

cross ref

∞

s

Ch 1 Fall

No valid

edge

∞

s

Running:
200MS/s ET

Sample

(T)

Ch 1 Rise

149.6ns

Running:
200MS/s ET

VOLTAGE SCALE = 2V/DIV

TA = +125°C

= +5V

V

DD

C

LOAD

R

LOAD

= 100pF

= 1kΩ

Sample

(T)

Ch 1 +Width

∞

s
Wfm does not
cross ref

Ch 1 –Width

∞

s
Wfm does not
cross ref

Ch 1 Rise

∞

s

No valid

edge

Ch 1 Fall

139.5ns

Edge Slope

TIME SCALE = 250ns/DIV

Figure 9. TMP03 Output Fall Time at +125°C

Running:
200MS/s ET

VOLTAGE SCALE = 2V/DIV

C
R

LOAD
LOAD

= 100pF

= 0

Sample

(T)

TA = +25°C

= +5V

V

DD

Ch 1 +Width

∞

s
Wfm does not
cross ref

Ch 1 –Width

∞

s

Wfm does not
cross ref

Ch 1 Rise

∞

s

No valid

edge

Ch 1 Fall

127.6ns

Figure 12. TMP04 Output Rise Time at +25°C

REV. 0

TIME SCALE = 250ns/DIV

Figure 10. TMP04 Output Fall Time at +25°C

Running:
200MS/s ET

VOLTAGE SCALE = 2V/DIV

C
R

Sample

(T)

= 100pF

LOAD

= 0

LOAD

TIME SCALE = 250ns/DIV

TA = +125°C

= +5V

V

DD

Ch 1 +Width

∞

s
Wfm does not
cross ref

Ch 1 –Width

∞

s
Wfm does not
cross ref

Ch 1 Rise

∞

s

No valid

edge

Ch 1 Fall

188.0ns

Figure 11. TMP04 Output Fall Time at +125°C

–7–

Figure 13. TMP04 Output Rise Time at +125°C

2500

TA = +25°C

= +5V

2000

V

S

R

LOAD

= ∞

FALL TIME

1500

TIME – ns

1000

RISE TIME

500

0

0 5000500

1000 1500 2000 2500 3000 3500 4000 4500

LOAD CAPACITANCE – pF

Figure 14. TMP04 Output Rise & Fall Times
vs. Capacitive Load

TMP03/TMP04

TEMPERATURE – °C

5

4

3

–75 175

START-UP SUPPLY VOLTAGE – Volts

–25 25 75 125

4.5

3.5

R

LOAD

= 10kΩ

START-UP VOLTAGE DEFINED AS OUTPUT READING
BEING WITHIN ±5°C OF OUTPUT AT +4.5V SUPPLY

5

4

3

V+ = +5V

2

R

= 10kΩ

LOAD

1

0

–1

–2

OUTPUT ACCURACY – °C

–3

–4
–5

–50 125–25

TMP03

TMP04

MAXIMUM LIMIT

MEASUREMENTS IN
STIRRED OIL BATH

MINIMUM LIMIT

0255075100

TEMPERATURE – °C

Figure 15. Output Accuracy vs. Temperature

V+ = +5V
R

= 10kΩ

LOAD

OUTPUT

STARTS

LOW

OUTPUT
STARTS

HIGH

V+

0 10010 20 30 40 50 60 70 80 90

0, T2

0, T1

Figure 16. Start-Up Response

1100

1050

1000

950

900

850

SUPPLY CURRENT – µA

800

750

V+ = +5V
NO LOAD

–75 175

–25 25 75 125

Figure 17. Supply Current vs. Temperature

TEMP°CT2msT1

T1 T2

T1 T2

TIME – ms

TMP04

TEMPERATURE – °C

TYPICAL VALUES

ms

–55 15 10
+25 20 10
+125 35 10

TMP03

Figure 18. Start-Up Voltage vs. Temperature

1600

1400

1200

1000

800

600

SUPPLY CURRENT – µA

400

200

0

TA = +25°C
NO LOAD

081

234567

SUPPLY VOLTAGE – Volts

Figure 19. Supply Current vs. Supply Voltage

4

3.5
V+ = 4.5 - 7V

3

R

= 10kΩ

LOAD

2.5

2

1.5

1

POWER SUPPLY REJECTION – °C/V

0.5

0

–75

–25 25 75 125

TEMPERATURE – °C

175

Figure 20. Power Supply Rejection vs. Temperature

–8–

REV. 0

TMP03/TMP04

TIME – sec

25

0 30025

OUTPUT TEMPERATURE – °C

50 75 100 125 150 175 200 275

105

VS = +5V
R

LOAD

= 10kΩ

TRANSITION FROM +100°C STIRRED
OIL BATH TO STILL +25°C AIR

τ ~ 23 sec (SOIC, NO SOCKET)

τ

~

40 sec (TO-92, NO SOCKET)

SOIC

TO-92

100

95
90
85
80
75
70
65
60
55
50
45
40
35
30

250225

1

V+ = +5V dc ± 50mV ac
R

= 10kΩ

LOAD

0.5

0

–0.5

DEVIATION IN TEMPERATURE – °C

–1

NOMINAL PSRR

FREQUENCY – Hz

10M100 10k1 10 1k 100k 1M

Figure 21. Power Supply Rejection vs. Frequency

400

350

300

250

V+ = +5V

I

LOAD

= 5mA

20

18

VOL = +1V

16

V+ = +5V

14

12

10

8

SINK CURRENT – mA

6

4

2

–75 150–25 25 75 125

TEMPERATURE – °C

Figure 24. TMP03 Open-Collector Sink Current
vs. Temperature

200

150

100

50

OPEN-COLLECTOR OUTPUT VOLTAGE – mV

0

–75 175

Figure 22. TMP03 Open-Collector Output Voltage
vs. Temperature

140

120

100

80

60

TO-92 – WITH SOCKET

40

τ TIME CONSTANT – sec

REV. 0

20

0

0 700100

Figure 23. Thermal Time Constant in Forced Air

I

= 1mA

LOAD

I

= 0.5mA

LOAD

–25 25 75 125

TEMPERATURE – *C

TRANSITION FROM +100°C OIL BATH
TO FORCED +25°C AIR

V+ = +5V

= 10kΩ

R

LOAD

TO-92 – NO SOCKET

SOIC – NO SOCKET

200 300 400 500 600

AIR VELOCITY – FPM

Figure 25. Thermal Response Time in Still Air

SOIC

100

V+ = +5V
R

= 10kΩ

LOAD

1.25 sec (SOIC IN SOCKET)

2 sec (TO-92 IN SOCKET)

TIME – sec

OUTPUT TEMPERATURE – °C

25

06010

TO-92

τ ≅
τ ≅

TRANSITION FROM STILL +25°C AIR
TO STIRRED +100°C OIL BATH

20 30 40 50

Figure 26. Thermal Response Time in Stirred Oil Bath

–9–

TMP03/TMP04

TMP03

D

OUT

D

OUT

TMP04

V+

APPLICATIONS INFORMATION
Supply Bypassing

Precision analog products, such as the TMP03/TMP04, require
a well filtered power source. Since the TMP03/TMP04 operate
from a single +5 V supply, it seems convenient to simply tap
into the digital logic power supply. Unfortunately, the logic
supply is often a switch-mode design, which generates noise in
the 20 kHz to 1 MHz range. In addition, fast logic gates can
generate glitches hundred of millivolts in amplitude due to
wiring resistance and inductance.

If possible, the TMP03/TMP04 should be powered directly
from the system power supply. This arrangement, shown in
Figure 27, will isolate the analog section from the logic switching
transients. Even if a separate power supply trace is not available,
however, generous supply bypassing will reduce supply-line
induced errors. Local supply bypassing consisting of a 10 µF
tantalum electrolytic in parallel with a 0.1 µF ceramic capacitor
is recommended (Figure 28a).

TTL/CMOS

LOGIC

CIRCUITS

0.1µF

TMP03/
TMP04

+5V

POWER SUPPLY

10µF
TANT

Figure 27. Use Separate Traces to Reduce Power Supply
Noise

+5V

+5V

V+

0.1µF10µF

TMP03/

D

TMP04

OUT

GND

0.1µF10µF

TMP03/
TMP04

GND

V+

a. b.
Figure 28. Recommended Supply Bypassing for the
TMP03/TMP04

The quiescent power supply current requirement of the
TMP03/TMP04 is typically only 900 µA. The supply current
will not change appreciably when driving a light load (such as a
CMOS gate), so a simple RC filter can be added to further
reduce power supply noise (Figure 28b).

50Ω

D

OUT

TMP03/TMP04 Output Configurations

The TMP03 (Figure 29a) has an open-collector NPN output
which is suitable for driving a high current load, such as an
opto-isolator. Since the output source current is set by the pull­up resistor, output capacitance should be minimized in TMP03
applications. Otherwise, unequal rise and fall times will skew the
pulse width and introduce measurement errors. The NPN
transistor has a breakdown voltage of 18 V.

a. b.

Figure 29. TMP03/TMP04 Digital Output Structure

The TMP04 has a “totem-pole” CMOS output (Figure 29b)
and provides rail-to-rail output drive for logic interfaces. The
rise and fall times of the TMP04 output are closely matched, so
that errors caused by capacitive loading are minimized. If load
capacitance is large, for example when driving a long cable, an
external buffer may improve accuracy. See the “Remote
Temperature Measurement” section of this data sheet for
suggestions.

Interfacing the TMP03 to Low Voltage Logic

The TMP03’s open-collector output is ideal for driving logic
gates that operate from low supply voltages, such as 3.3 V. As
shown in Figure 30, a pull-up resistor is connected from the low
voltage logic supply (2.9 V, 3 V, etc.) to the TMP03 output.
Current through the pull-up resistor should be limited to about
1 mA, which will maintain an output LOW logic level of
<200 mV.

TMP03

+5V

V+

GND

D

OUT

+3.3V

3.3kΩ

TO LOW VOLTAGE
LOGIC GATE INPUT

Figure 30. Interfacing to Low Voltage Logic

Remote Temperature Measurement

When measuring a temperature in situations where high
common-mode voltages exist, an opto-isolator can be used to
isolate the output (Figure 31a). The TMP03 is recommended in
this application because its open-collector NPN transistor has a
higher current sink capability than the CMOS output of the
TMP04. To maintain the integrity of the measurement, the
opto-isolator must have relatively equal turn-on and turn-off
times. Some Darlington opto-isolators, such as the 4N32, have
a turn-off time that is much longer than their turn-on time. In
this case, the T1 time will be longer than T2, and an erroneous
reading will result. A PNP transistor can be used to provide
greater current drive to the opto-isolator (Figure 31b). An opto­isolator with an integral logic gate output, such as the H11L1
from Quality Technology, can also be used (Figure 32).

–10–

REV. 0

TMP03/TMP04

ADM485

V+

D

OUT

GND

TMP04

+5V

1

2

3

4

1

2

3

DE

NC

+5V

DI

8

B
A

6

V

CC

7

5

+5V

V+

TMP03

GND

620Ω

OPTO-COUPLER

D

OUT

V

LOGIC

4.7kΩ

a.

+5V

V+

TMP03

GND

10kΩ

2N2907

OPTO-COUPLER

4.3kΩ

D

OUT

270Ω

V

LOGIC

430Ω

b.

Figure 31. Optically Isolating the Digital Output

+5V

V+

TMP03

GND

680Ω

D

OUT

H11L1

+5V

4.7kΩ

Figure 32. An Opto-Isolator with Schmitt Trigger Logic
Gate Improves Output Rise and Fall Times

The TMP03 and TMP04 are superior to analog-output
transducers for measuring temperature at remote locations,
because the digital output provides better noise immunity than
an analog signal. When measuring temperature at a remote
location, the ratio of the output pulses must be maintained. To
maintain the integrity of the pulse width, an external buffer can
be added. For example, adding a differential line driver such as
the ADM485 permits precise temperature measurements at
distances up to 4000 ft. (Figure 33). The ADM485 driver and
receiver skew is only 5 ns maximum, so the TMP04 duty cycle
is not degraded. Up to 32 ADM485s can be multiplexed onto
one line by providing additional decoding.

As previously mentioned, the digital output of the TMP03/
TMP04 provides excellent noise immunity in remote measurement
applications. The user should be aware, however, that heat from
an external cable can be conducted back to the TMP03/TMP04.
This heat conduction through the connecting wires can influence
the temperature of the TMP03/TMP04. If large temperature
differences exist within the sensor environment, an opto­isolator, level shifter or other thermal barrier can be used to
minimize measurement errors.

REV. 0

Figure 33. A Differential Line Driver for Remote Tempera­ture Measurement

Microcomputer Interfaces

The TMP03/TMP04 output is easily decoded with a micro­computer. The microcomputer simply measures the T1 and T2
periods in software or hardware, and then calculates the temp­erature using the equation in the Output Encoding section of
this data sheet (page 4). Since the TMP03/TMP04’s output is
ratiometric, precise control of the counting frequency is not
required. The only timing requirements are that the clock
frequency be high enough to provide the required measurement
resolution (see the Output Encoding section for details) and
that the clock source be stable. The ratiometric output of the
TMP03/TMP04 is an advantage because the microcomputer’s
crystal clock frequency is often dictated by the serial baud rate
or other timing considerations.

Pulse width timing is usually done with the microcomputer’s
on-chip timer. A typical example, using the 80C51, is shown in
Figure 34. This circuit requires only one input pin on the
microcomputer, which highlights the efficiency of the TMP04’s
pulse width output format. Traditional serial input protocols,
with data line, clock and chip select, usually require three or
more I/O pins.

+5V

V+

D

TMP04

GND

OUT

INPUT
PORT 1.0

TIMER 0
(16 BITS)

80C51

MICROCOMPUTER

TIMER 1

(16 BITS)

OSC

÷

12

TMOD REGISTER

TIMER 1

TIMER 0

TCON REGISTER

TIMER 0 TIMER 1

Figure 34. A TMP04 Interface to the 80C51 Microcomputer

The 80C51 has two 16-bit timers. The clock source for the
timers is the crystal oscillator frequency divided by 12. Thus, a
crystal frequency of 12 MHz or greater will provide resolution of
1 µs or less.

The 80C51 timers are controlled by two dedicated registers.
The TMOD register controls the timer mode of operation,
while TCON controls the start and stop times. Both the TMOD
and TCON registers must be set to start the timer.

–11–

TMP03/TMP04

Software for the interface is shown in Listing 1. The program
monitors the TMP04 output, and turns the counters on and off
to measure the duty cycle. The time that the output is high is
measured by Timer 0, and the time that the output is low is

Listing 1. An 80C51 Software Routine for the TMP04

;
; Test of a TMP04 interface to the 8051,
; using timer 0 and timer 1 to measure the duty cycle
;
; This program has three steps:
; 1. Clear the timer registers, then wait for a low-to­; high transition on input P1.0 (which is connected
; to the output of the TMP04).
; 2. When P1.0 goes high, timer 0 starts. The program
; then loops, testing P1.0.
; 3. When P1.0 goes low, timer 0 stops & timer 1 starts. The
; program loops until P1.0 goes low, when timer 1 stops
; and the TMP04’s T1 and T2 values are stored in Special
; Function registers 8AH through 8DH (TL0 through TH1).
;
;
; Primary controls
$MOD51
$TITLE(TMP04 Interface, Using T0 and T1)
$PAGEWIDTH(80)
$DEBUG
$OBJECT
;
; Variable declarations
;
PORT1 DATA 90H ;SFR register for port 1
;TCON DATA 88H ;timer control
;TMOD DATA 89H ;timer mode
;TH0 DATA 8CH ;timer 0 hi byte
;TH1 DATA 8DH ;timer 1 hi byte
;TL0 DATA 8AH ;timer 0 lo byte
;TL1 DATA 8BH ;timer 1 low byte
;
;

ORG 100H ;arbitrary start
;
READ_TMP04: MOV A,#00 ;clear the

MOV TH0,A ; counters

MOV TH1,A ; first

MOV TL0,A ;

MOV TL1,A ;
WAIT_LO: JB PORT1.0,WAIT_LO ;wait for TMP04 output to go low

MOV A,#11H ;get ready to start timer0

MOV TMOD,A
WAIT_HI: JNB PORT1.0,WAIT_HI ;wait for output to go high
;
;Timer 0 runs while TMP04 output is high
;

SETB TCON.4 ;start timer 0
WAITTIMER0: JB PORT1.0,WAITTIMER0

CLR TCON.4 ;shut off timer 0
;
;Timer 1 runs while TMP04 output is low
;

SETB TCON.6 ;start timer 1
WAITTIMER1: JNB PORT1.0,WAITTIMER1

CLR TCON.6 ;stop timer 1

MOV A,#0H ;get ready to disable timers

MOV TMOD,A

RET

END

measured by Timer 1. When the routine finishes, the results are
available in Special Function Registers (SFRs) 08AH through
08DH.

–12–

REV. 0

TMP03/TMP04

When the READ_TMP04 routine is called, the counter registers
are cleared. The program sets the counters to their 16-bit mode,
and then waits for the TMP04 output to go high. When the
input port returns a logic high level, Timer 0 starts. The timer
continues to run while the program monitors the input port.
When the TMP04 output goes low, Timer 0 stops and Timer 1
starts. Timer 1 runs until the TMP04 output goes high, at
which time the TMP04 interface is complete. When the
subroutine ends, the timer values are stored in their respective
SFRs and the TMP04’s temperature can be calculated in
software.

Since the 80C51 operates asynchronously to the TMP04, there
is a delay between the TMP04 output transition and the start of
the timer. This delay can vary between 0 µs and the execution
time of the instruction that recognized the transition. The
80C51’s “jump on port.bit” instructions (JB and JNB) require
24 clock cycles for execution. With a 12 MHz clock, this
produces an uncertainty of 2 µs (24 clock cycles/12 MHz) at
each transition of the TMP04 output. The worst case condition
occurs when T1 is 4 µs shorter than the actual value and T2 is 4
µs longer. For a +25°C reading (“room temperature”), the
nominal error caused by the 2 µs delay is only about ± 0.15°C.

The TMP04 is also easily interfaced to digital signal processors
(DSPs), such as the ADSP-210x series. Again, only a single I/O
pin is required for the interface (Figure 35).

+5V

V+

D

TMP04

GND

OUT

FI (FLAG IN)

16-BIT DOWN

COUNTER

ADSP-210x

TIMER
ENABLE

10MHz

CLOCK

OSCILLATOR

÷

n

Figure 35. Interfacing the TMP04 to the ADSP-210x Digital
Signal Processor

The ADSP-2101 only has one counter, so the interface software
differs somewhat from the 80C51 example. The lack of two
counters is not a limitation, however, because the DSP
architecture provides very high execution speed. The ADSP­2101 executes one instruction for each clock cycle, versus one
instruction for twelve clock cycles in the 80C51, so the ADSP­2101 actually produces a more accurate conversion while using
a lower oscillator frequency.

The timer of the ADSP-2101 is implemented as a down
counter. When enabled by means of a software instruction, the
counter is decremented at the clock rate divided by a
programmable prescaler. Loading the value n – 1 into the
prescaler register will divide the crystal oscillator frequency by n.

For the circuit of Figure 35, therefore, loading 4 into the
prescaler will divide the 10 MHz crystal oscillator by 5 and
thereby decrement the counter at a 2 MHz rate. The TMP04
output is ratiometric, of course, so the exact clock frequency is
not important.

A typical software routine for interfacing the TMP04 to the
ADSP-2101 is shown in Listing 2. The program begins by
initializing the prescaler and loading the counter with 0FFFF

.

H

The ADSP-2101 monitors the FI flag input to establish the
falling edge of the TMP04 output, and starts the counter. When
the TMP04 output goes high, the counter is stopped. The
counter value is then subtracted from 0FFFF

to obtain the

H

actual number of counts, and the count is saved. Then the
counter is reloaded and runs until the TMP04 output goes low.
Finally, the TMP04 pulse widths are converted to temperature
using the scale factor of Equation 1.

Some applications may require a hardware interface for the
TMP04. One such application could be to monitor the
temperature of a high power microprocessor. The TMP04
interface would be included as part of the system ASIC, so that
the microprocessor would not be burdened with the overhead of
timing the output pulse widths.

A typical hardware interface for the TMP04 is shown in Figure

36. The circuit measures the output pulse widths with a
resolution of ±1 µs. The TMP04 T1 and T2 periods are
measured with two cascaded 74HC4520 8-bit counters. The
counters, accumulating clock pulses from the 1 MHz external
oscillator, have a maximum period of 65 ms.

The logic interface is straightforward. On both the rising and
falling edges of the TMP04 output, an exclusive-or gate
generates a pulse. This pulse triggers one half of a 74HC4538
dual one-shot. The pulse from the one-shot is ANDed with the
TMP04 output polarity to store the counter contents in the
appropriate output registers. The falling edge of this pulse also
triggers the second one-shot, which generates a reset pulse for
the counters. After the reset pulse, the counters will begin to
count the next TMP04 output phase.

As previously mentioned, the counters have a maximum period
of 65 ms with a 1 MHz clock input. However, the TMP04’s T1
and T2 times will never exceed 32 ms. Therefore the most
significant bit (MSB) of counter #2 will not go high in normal
operation, and can be used to warn the system that an error
condition (such as a broken connection to the TMP04) exists.

The circuit of Figure 36 will latch and save both the T1 and T2
times simultaneously. This makes the circuit suitable for
debugging or test purposes as well as for a general purpose
hardware interface. In a typical ASIC application, of course, one
set of latches could be eliminated if the latch contents, and the
output polarity, were read before the next phase reversal of the
TMP04.

REV. 0

–13–

TMP03/TMP04

Listing 2. Software Routine for the TMP04-to-ADSP-210x Interface

;
{ ADSP-21XX Temperature Measurement Routine TEMPERAT.DSP

Altered Registers: ax0, ay0, af, ar,

si, sr0,

my0, mr0, mr1, mr2.
Return value: ar —> temperature result in 14.2 format
Computation time: 2 * TMP04 output period

}
.MODULE/RAM/BOOT=0 TEMPERAT; { Beginning TEMPERAT Program }
.ENTRY TEMPMEAS; { Entry point of this subroutine }
.CONST PRESCALER=4;
.CONST TIMFULSCALE=0Xffff;
TEMPMEAS: si=PRESCALER; { For timer prescaler }

sr0=TIMFULSCALE; { Timer counter full scale }
dm(0x3FFB)=si; { Timer Prescaler set up to 5 }
si=TIMFULSCALE; { CLKin=10MHz,Timer Period=32.768ms }
dm(0x3FFC)=si; { Timer Counter Register to 65535 }
dm(0x3FFD)=si; { Timer Period Register to 65535 }

imask=0x01; { Unmask Interrupt timer }
TEST1: if not fi jump TEST1; { Check for FI=1 }
TEST0: if fi jump TEST0; { Check for FI=0 to locate transition }

ena timer; { Enable timer, count at a 500ns rate }
COUNT2: if not fi jump COUNT2; { Check for FI=1 to stop count }

dis timer;

ay0=dm(0x3FFC); { Save counter=T2 in ALU register }

ar=sr0-ay0;

ax0=ar;

dm(0x3FFC)=si; { Reload counter at full scale }

ena timer;
COUNT1: if fi jump COUNT1; { Check for FI=0 to stop count }

dis timer;

ay0=dm(0x3FFC); { Save counter=T1 in ALU register }

ar=sr0-ay0;

my0=400;

mr=ar*my0(uu); { mr=400*T1 }

ay0=mr0; { af=MSW of dividend, ay0=LSW }

ar=mr1; af=pass ar; { ax0=16-bit divisor }
COMPUTE: astat=0; { To clear AQ flag }

divq ax0; divq ax0; { Division 400*T1/T2 }

divq ax0; divq ax0; { with 0.3 < T1/T2 < 0.7 }

divq ax0; divq ax0;

divq ax0; divq ax0;

divq ax0; divq ax0;

divq ax0; divq ax0;

divq ax0; divq ax0;

divq ax0; divq ax0;

divq ax0; divq ax0; { Result in ay0 }

ax0=0x03AC; { ax0=235*4 }

ar=ax0-ay0; { ar=235-400*T1/T2, result in øC }

rts; { format 14.2 }
.ENDMOD; { End of the subprogram }

–14–

REV. 0

TMP03/TMP04

V

CC

EN

74HC4520 #2

Q0 Q1Q2Q3 Q0 Q1 Q2

Q3

7

15

9

8

16

2

3456

111213 14

EN

10

CLK

CLK

GND

RESET

RESET

1

+5V

+5V

V+

D

OUT

GND

TMP04

1
2

3

1

2

3

4
5

6

74HC08

+5V

V

CC

LE

OUT

GND

74HC373

Q1 Q2Q3Q4

Q5 Q6 Q7 Q8

13 14 17 18

10

1

3

4

7

8

20

11

2569

121516 19

D1 D2 D3 D4

D5 D6 D7 D8

+5V

V

CC

LE

OUT

GND

74HC373

Q1 Q2Q3Q4

Q5 Q6 Q7 Q8

13 14 17 18

10

1

3

4

7

8

20

11

2569

121516 19

D1 D2 D3 D4

D5 D6 D7 D8

+5V

V

CC

LE

OUT
GND

74HC373

Q1 Q2Q3Q4

Q5 Q6 Q7 Q8

13 14 17 18

10

1

3

4

7

8

20

11

2569

121516 19

D1 D2 D3 D4

D5 D6 D7 D8

+5V

V

CC

LE

OUT

GND

74HC373

Q1 Q2Q3Q4

Q5 Q6 Q7 Q8

13 14 17 18

10

1

3

4

7

8

20

11

2569

121516 19

D1 D2 D3 D4

D5 D6 D7 D8

+5V

GND

74HC4538

T2

T1

CLR

A

QB

13

14

10

8

11

16

6

9

12

15

20pF

NC

+5V

V

CC

EN

74HC4520 #1

Q0 Q1Q2Q3 Q0Q1Q2

Q3

7

15

9

8

16

2

3456

111213 14

EN

10

CLK

CLK

GND

RESET

RESET

1

1MHZ

CLOCK

3.9kΩ

+5V

Q

GND

74HC86

T2

T1

CLR

A

Q

B

3

2

6

8

5

7

4

1

20pF

NC

1kΩ

+5V

Q

V

CC

+5V

4
5

10kΩ

10pF

10µF

0.1µF

T1 DATA (MICROSECONDS) T2 DATA (MICROSECONDS)

Figure 36. A Hardware Interface for the TMP04

Monitoring Electronic Equipment

The TMP03/TMP04 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/TMP04 are used to measure the temperature of a
nearby heat source, the thermal impedance between the heat
source and the TMP03/TMP04 must be considered. Often, a
thermocouple or other temperature sensor is used to measure

REV. 0

the temperature of the source while the TMP03/TMP04
temperature is monitored by measuring T1 and T2. Once the
thermal impedance is determined, the temperature of the heat
source can be inferred from the TMP03/TMP04 output.

One example of using the TMP04 to monitor a high power
dissipation microprocessor or other IC is shown in Figure 37.
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 pulse width would be measured (see the
Hardware Interface section of this data sheet for a typical

–15–

TMP03/TMP04

8

5

4

1

0.122 (3.10)

0.114 (2.90)

0.256 (6.50)

0.246 (6.25)

0.177 (4.50)

0.169 (4.30)

PIN 1

0.0256 (0.65)
BSC

SEATING

PLANE

0.006 (0.15)

0.002 (0.05)

0.0118 (0.30)

0.0075 (0.19)

0.0433
(1.10)
MAX

0.0079 (0.20)

0.0035 (0.090)

0.028 (0.70)

0.020 (0.50)

8°
0°

interface schematic). The TMP04 pulse output provides a
significant advantage in this application because it produces a
linear temperature output while needing only one I/O pin and
without requiring an A/D converter.

FAST MICROPROCESSOR, DSP, ETC.,
IN PGA PACKAGE

PGA SOCKET

TMP04 IN SURFACE
MOUNT PACKAGE

PC BOARD

Figure 37. Monitoring the Temperature of a High Power
Microprocessor Improves System Reliability

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

3-Pin TO-92

0.205 (5.20)

0.175 (4.96)

0.210 (5.33)

0.170 (4.38)

0.050
(1.27)
MAX

0.019 (0.482)

0.016 (0.407)
SQUARE

SEATING

PLANE

0.135
(3.43)

MIN

0.500

(12.70)

MIN

Thermal Response Time

The time required for a temperature sensor to settle to a
specified accuracy is a function of the thermal mass of, and the
thermal conductivity between, the sensor and the object being
sensed. Thermal mass is often considered equivalent to
capacitance. Thermal conductivity is commonly specified using
the symbol Θ, and can be thought of as thermal resistance. It is
commonly specified in units of degrees per watt of power
transferred across the thermal joint. Thus, the time required for
the TMP03/TMP04 to settle to the desired accuracy is
dependent on the package selected, the thermal contact
established in that particular application, and the equivalent
power of the heat source. In most applications, the settling time
is probably best determined empirically. The TMP03/TMP04
output operates at a nominal frequency of 35 Hz at +25°C, so
the minimum settling time resolution is 27 ms.

8-Pin SOIC (SO-8)

0.1968 (5.00)

0.1890 (4.80)

8

0.0500
(1.27)

BSC

5

0.2440 (6.20)

41

0.2284 (5.80)

0.0688 (1.75)

0.0532 (1.35)

0.0192 (0.49)

0.0138 (0.35)

0.0098 (0.25)

0.0075 (0.19)

0.0196 (0.50)

0.0099 (0.25)

8°
0°

0.0500 (1.27)

0.0160 (0.41)

x 45°

0.1574 (4.00)

0.1497 (3.80)

PIN 1

0.0098 (0.25)

0.0040 (0.10)

SEATING

PLANE

C2063–18–9/95

0.105 (2.66)

0.095 (2.42)

0.105 (2.66)

0.080 (2.42)

0.105 (2.66)

0.080 (2.42)

BOTTOM VIEW

123

0.055 (1.39)

0.045 (1.15)

0.165 (4.19)

0.125 (3.94)

–16–

8-Pin TSSOP (RU-8)

PRINTED IN U.S.A.

REV. 0