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–