TMP03/TMP04
REV. A
4
(continued from page 1)
The TMP03 is a powerful, complete temperature measurement
system with digital output, on a single chip. The onboard tem-
perature 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-to-
digital 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.
VOLTAGE REF
AND VPTAT
CLOCK
GENERATOR
COMPARATOR
1-BIT
DAC
INTEGRATOR
MODULATOR
DIGITAL
FILTER
TMP03/04
OUT
(SINGLE-BIT)
Figure 1.  TMP03 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
which results in a serial digi-
tal 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 neatly
avoids major error sources common to other modulation tech-
niques, 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 repre-
sentation 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 uti-
lized in the TMP03 avoid this problem and allow the overall
circuit to fit into a compact, 3-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 TMP03s clock is
irrelevant, and the effects of clock variations are effectively can-
celed upon decoding by the digital filter.
The output of the TMP03 is a square wave with a nominal
frequency of 35 Hz (?0%) at 25癈. The output format is
readily decoded by the user as follows:
T1
T2
Figure 2.  TMP03 Output Format
Temperature (癈) =
235
400 ?SPAN class="pst TMP03FS-REEL_2285105_10">T1
T2
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
Temperature (癋) =
455
720 ?SPAN class="pst TMP03FS-REEL_2285105_10">T1
T2
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
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 peri-
ods 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 or the
users counting clock.
相關代理商/技術參數 |
參數描述 |
TMP03FSZ |
功能描述:IC SENSOR TEMP/SERIAL OC 8SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標準包裝:2,500 系列:SilentSense™ 功能:溫度監控系統(傳感器) 傳感器類型:內部和外部 感應溫度:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠程(最大) 拓撲:ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應商設備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND |
TMP03FSZ-REEL |
功能描述:IC SENSOR TEMP/SERIAL OC 8SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標準包裝:2,500 系列:SilentSense™ 功能:溫度監控系統(傳感器) 傳感器類型:內部和外部 感應溫度:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠程(最大) 拓撲:ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應商設備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND |
TMP03FT9 |
功能描述:IC SENSOR TEMP/SERIAL OC TO-92-3 RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標準包裝:2,500 系列:SilentSense™ 功能:溫度監控系統(傳感器) 傳感器類型:內部和外部 感應溫度:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠程(最大) 拓撲:ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應商設備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND |
TMP03FT9Z |
功能描述:IC SENSOR TEMP/SERIAL OC TO-92-3 RoHS:是 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標準包裝:2,500 系列:SilentSense™ 功能:溫度監控系統(傳感器) 傳感器類型:內部和外部 感應溫度:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠程(最大) 拓撲:ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應商設備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND |
TMP03GBC |
制造商:AD 制造商全稱:Analog Devices 功能描述:Serial Digital Output Thermometers |
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