Microelectromechanical apparatus having a measuring range selector
10203252 ยท 2019-02-12
Assignee
Inventors
- Yu-Wen Hsu (Tainan, TW)
- Feng-Chia Hsu (Kaohsiung, TW)
- Chao-Ta Huang (Hsinchu, TW)
- Shih-Ting Lin (Hualien County, TW)
Cpc classification
B81B7/008
PERFORMING OPERATIONS; TRANSPORTING
B81B7/02
PERFORMING OPERATIONS; TRANSPORTING
G01K1/02
PHYSICS
International classification
G01K7/00
PHYSICS
B81B7/02
PERFORMING OPERATIONS; TRANSPORTING
G01K1/00
PHYSICS
B81B7/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A MEMS apparatus having measuring range selector including a sensor and an IC chip is provided. The sensor includes a sensing device. The IC chip includes a voltage range selector, an analog front end, a control device and an A/D converter. The sensing device is configured to detect the physical quantity and generate a sensing voltage. The voltage range selector is configured to select a sub-voltage range having a first upper-bound and a first lower-bound. The analog front end is configured to receive the sensing voltage and output a first voltage. The A/D converter has a full scale voltage range having a second lower-bound and a second upper-bound. A ratio of the full scale voltage range to the sub-voltage range is defined as a gain factor. A difference obtained by subtracting the first lower-bound from the first voltage is defined as a shift factor. The control device is configured to adjust the first voltage to the second voltage according to the gain factor and the shift factor.
Claims
1. A MEMS apparatus, comprising: a sensor, comprising: a sensing device, configured to detect a physical quantity and generate a sensing voltage; an IC chip, comprising: a voltage range selector, configured to select a sub-voltage range, wherein the sub-voltage range has a first lower-bound and a first upper-bound; an analog front end, configured to receive the sensing voltage and output a first voltage; a control device, configured to adjust the first voltage to a second voltage; and an A/D converter, configured to receive the second voltage, wherein the A/D converter has a full scale voltage range, and the full scale voltage range has a second lower-bound and a second upper-bound, wherein the first voltage is between the first lower-bound and the first upper-bound, a ratio of the full scale voltage range to the sub-voltage range is defined as a gain factor, a difference obtained by subtracting the first lower-bound from the first voltage is defined as a shift factor, and the control device is configured to adjust the first voltage to the second voltage according to the gain factor and the shift factor.
2. The MEMS apparatus of claim 1, wherein the second voltage is obtained from a product of the gain factor and the shift factor.
3. The MEMS apparatus of claim 1, wherein the analog front end has a first voltage range, and the first voltage range includes the sub-voltage range.
4. The MEMS apparatus of claim 1, wherein the physical quantity is a temperature.
5. The MEMS apparatus of claim 1, wherein the sensor further comprises a detecting device, the detecting device is configured to detect the physical quantity and generate an electrical signal, and the voltage range selector is configured to select the sub-voltage range according to the electrical signal.
6. The MEMS apparatus of claim 5, wherein the sensing device is electrically connected to the analog front end, and the detecting device is electrically connected to the voltage range selector.
7. The MEMS apparatus of claim 6, wherein the detecting device comprises a thermal radiation absorbing layer, the physical quantity is a radiant heat, and the electrical signal is an electrical resistance signal.
8. The MEMS apparatus of claim 7, wherein the sensing device comprises at least one thermal pile.
9. The MEMS apparatus of claim 5, wherein the IC chip further comprises a memory configured to store a first voltage-temperature diagram of the sensing device and an electrical signal-temperature diagram of the detecting device, and the first voltage-temperature diagram and the electrical signal-temperature diagram respectively comprise a plurality of temperature ranges, wherein the temperature ranges of the first voltage-temperature diagram are the same as the temperature ranges of the electrical signal-temperature diagram.
10. The MEMS apparatus of claim 9, wherein the electrical signal is an electrical resistance signal, and the electrical signal-temperature diagram is an electrical resistance-temperature diagram.
11. The MEMS apparatus of claim 9, wherein the voltage range selector is configured to select a first temperature range corresponding to the electrical signal according to the electrical signal-temperature diagram, the voltage range selector is configured to select a second temperature range having the same interval with the first temperature range from the first voltage-temperature diagram, and then the voltage range selector is configured to select a voltage range corresponding to the second temperature range from the first voltage-temperature diagram to be the sub-voltage range corresponding to the first voltage, wherein an upper endpoint of the first temperature range is the same as an upper endpoint of the second temperature range, and a lower endpoint of the first temperature range is the same as a lower endpoint of the second temperature range.
12. A MEMS apparatus, comprising: a sensor, comprising: a detecting device, configured to detect a physical quantity and generate an electrical signal; a sensing device, configured to detect the physical quantity and generate a sensing voltage; an IC chip, comprising: a voltage range selector, configured to select a sub-voltage range according to the electrical signal, wherein the sub-voltage range has a first lower-bound and a first upper-bound; an analog front end, configured to receive the sensing voltage and output a first voltage; a control device, configured to adjust the first voltage to a second voltage; and an A/D converter, configured to receive the second voltage, wherein the A/D converter has a full scale voltage range, and the full scale voltage range has a second lower-bound and a second upper-bound, wherein the detecting device is electrically connected to the voltage range selector, the sensing device is electrically connected to the analog front end, the first voltage is between the first lower-bound and the first upper-bound, a ratio of the full scale voltage range to the sub-voltage range is defined as a gain factor, a difference obtained by subtracting the first lower-bound from the first voltage is defined as a shift factor, and the control device is configured to adjust the first voltage to the second voltage according to the gain factor and the shift factor.
13. The MEMS apparatus of claim 12, wherein the second voltage is obtained from a product of the gain factor and the shift factor.
14. The MEMS apparatus of claim 12, wherein the detecting device comprises a thermal radiation absorbing layer, the physical quantity is a radiant heat, and the electrical signal is an electrical resistance signal.
15. The MEMS apparatus of claim 12, wherein the sensing device comprises at least one thermal pile.
16. A MEMS apparatus, configured to sense temperatures in different ranges, the MEMS apparatus comprising: a sensor, comprising: a detecting device, configured to detect a physical quantity and generate an electrical signal; a sensing device, configured to detect the physical quantity and generate a sensing voltage; an IC chip, comprising: a voltage range selector, configured to select a sub-voltage range according to the electrical signal, wherein the sub-voltage range has a first lower-bound and a first upper-bound; an analog front end, configured to receive the sensing voltage and output a first voltage; a control device, configured to adjust the first voltage to a second voltage; and an A/D converter, configured to receive the second voltage, wherein the A/D converter has a full scale voltage range, and the full scale voltage range has a second lower-bound and a second upper-bound, wherein the sensing device is electrically connected to the analog front end, the detecting device is electrically connected to the voltage range selector, the voltage range selector is configured to select the sub-voltage range according to the electrical signal such that the first voltage is between the first lower-bound and the first upper-bound, a ratio of the full scale voltage range to the sub-voltage range is defined as a gain factor, a difference obtained by subtracting the first lower-bound from the first voltage is defined as a shift factor, and the control device is configured to adjust the first voltage to the second voltage according to the gain factor and the shift factor, and the secd voltage is obtained from a product of the gain factor and the shift factor.
17. The MEMS apparatus of claim 16, wherein the IC chip further comprises a memory configured to store a first voltage-temperature diagram of the sensing device and an electrical signal-temperature diagram of the detecting device, and the first voltage-temperature diagram and the electrical signal-temperature diagram respectively comprise a plurality of temperature ranges, wherein the temperature ranges of the first voltage-temperature diagram are the same as the temperature ranges of the electrical signal-temperature diagram.
18. The MEMS apparatus of claim 16, wherein the physical quantity is a radiant heat, and the detecting device comprises a thermal radiation absorbing layer, the electrical signal is an electrical resistance signal, and the sensing device comprises at least one thermal pile.
19. The MEMS apparatus of claim 18, wherein the voltage range selector is configured to select a first temperature range corresponding to the electrical signal according to the electrical signal-temperature diagram, the voltage range selector is configured to select a second temperature range having the same interval with the first temperature range from the first voltage-temperature diagram, and then the voltage range selector is configured to select a voltage range corresponding to the second temperature range from the first voltage-temperature diagram to be the sub-voltage range corresponding to the first voltage.
20. A MEMS apparatus, configured to sense temperatures in different ranges, the MEMS apparatus comprising: a sensor, comprising: a sensing device, comprising at least one thermal pile, wherein the at least one thermal pile is configured to detect a radiant heat and generate a sensing voltage; a detecting device, comprising a thermal radiation absorbing layer, wherein the thermal radiation absorbing layer is configured to detect the radiant heat and generate an electrical signal; and a film; and an IC chip; wherein the thermal radiation absorbing layer is disposed on a surface of the film, the at least one thermal pile is disposed in the film, a portion of the film is disposed between the thermal radiation absorbing layer and the at least one thermal pile, the detecting device is thermally coupled to the at least one thermal pile, and the thermal radiation absorbing layer is electrically connected to the IC chip.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
(2)
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DETAILED DESCRIPTION
(8) In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
(9) The term electrically connected used in this specification (including claims) of the present application may refer to any direct or indirect connection means. For example, a first device is electrically connected to a second device should be interpreted as the first device is directly connected to the second device or the first device is indirectly connected to the second device through other devices or connection means.
(10)
(11) With reference to
(12) Referring to
(13) With reference to
(14) In detail, in the present embodiment, the film 119 is, for example, made of silicon oxide (SiOx), but the present disclosure is not limited thereto. The substrate 116 is disposed along an edge E of the film 119, and the substrate 116 is, for example, made of silicon (Si), but the present disclosure is not limited thereto. With the above configuration, most of the radiant heat is adapted to be transferred from the detecting device 112 to the sensing device 114 via at least a portion of the film 119 but is difficult to be transferred to the substrate 116. In other words, the detecting device 112 is thermally coupled to the at least one thermal pile 114a. Accordingly, a sensing accuracy of the MEMS apparatus 100 of the present embodiment can be further improved.
(15) On the other hand, in the present embodiment, the IC chip 120 includes a voltage range selector 122, an analog front end (AFE) 124, a control device 126, an A/D converter 128 and a memory 129. In more details, the IC chip 120 further includes a first A/D converter 121, a first calibration device 123, a first processing device 125a, a second calibration device 127 and a second processing device 125b.
(16) In general, the detecting device 112 in the sensor 110 is electrically connected to the voltage range selector 122 in the IC chip 120 via the conductive path 118. In view of
(17) In detail, the first A/D converter 121 is electrically connected to the detecting device 112 in the sensor 110 and the first calibration device 123. The first calibration device 123 is electrically connected to the first processing device 125a. The first processing device 125a is electrically connected to the voltage range selector 122. The voltage range selector 122 is electrically connected to the second processing device 125b. The control device 126 is electrically connected to the analog front end 124. The A/D converter 128 is electrically connected to the second calibration device 127. The second calibration device 127 is electrically connected to the second processing device 125b.
(18) In the present embodiment, the first calibration device 123, the first processing device 125a, the second processing device 125b, the control device 126 and the second calibration device 127 may be embedded in, for example, a central processing unit (CPU) composed of single-core or multi-core, a microprocessor for general purpose or special purpose, a digital signal processor (DSP), a programmable controller, an application specific integrated circuits (ASIC), a programmable logic device (PLD) or other similar devices, or a combination of the above devices, but the present disclosure is not limited to the above. Further, the memory 129 may be, for example, a random access memory (RAM), a read-only memory (ROM) or a flash memory and the like, but the present disclosure is not limited thereto.
(19) Specifically, in the present embodiment, the first A/D converter 121 is configured to receive the electrical signal S.sub.D (e.g., the electrical resistance signal R.sub.S) from the detecting device 112 and convert the electrical resistance signal R.sub.S into a digital electrical resistance signal R.sub.SD. The first calibration device 123 is configured to receive the digital electrical resistance signal R.sub.SD from the first A/D converter 121 and calibrate the digital electrical resistance signal R.sub.SD according to a standard blackbody (not illustrated). The first processing device 125a is configured to receive the calibrated digital electrical resistance signal R.sub.SD from the first calibration device 123 and convert the calibrated digital electrical resistance signal R.sub.SD into a temperature signal T.sub.S. The voltage range selector 122 is configured to receive the temperature signal T.sub.S from the first processing device 125a.
(20) Furthermore, in the present embodiment, the sensor 110 has a specification voltage range. The specification voltage range refers to a maximum voltage range of the sensing voltage V.sub.S of the sensor 110. After receiving the sensing voltage V.sub.S, the analog front end 124 amplifies the sensing voltage V.sub.S and outputs a first voltage V.sub.S1. The specification voltage range is also amplified to be a first voltage range. The voltage range selector 122 is configured to select a sub-voltage range SUBV, and the sub-voltage range SUBV is selected from the first voltage range generated by the analog front end 124. The sub-voltage range SUBV has a first lower-bound L.sub.S1 and a first upper-bound L.sub.S2. The voltage range selector 122 selects the sub-voltage range SUBV according to the electrical signal S.sub.D from the detecting device 112 such that the first voltage V.sub.S1 is between the first lower-bound L.sub.S1 and the first upper-bound L.sub.S2. To be specific, the voltage range selector 122 is configured to select the sub-voltage range SUBV according to the temperature signal T.sub.S converted form the electrical signal S.sub.D. In the following paragraphs, how the voltage range selector 122 selects the sub-voltage range SUBV will be described in details.
(21) With reference to
(22) Referring to
(23) Referring back to
(24) Referring to
(25) Referring back to
(26) Referring to
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In the equation above, the sub-voltage range SUBV takes the voltage range V.sub.3 to V.sub.2 as an example, but the present disclosure is not limited thereto.
Accordingly, the step of adjusting the first voltage V.sub.S1 to the second voltage V.sub.S2 is completed by the control device 126.
(28) Referring to
(29) Specifically, the A/D converter 128 divides the full scale voltage range V.sub.f2 to V.sub.f1 into eight different voltage ranges. Those voltage ranges are, for example, a voltage range V.sub.f1 to V.sub.f11, a voltage range V.sub.f11 to V.sub.f12, a voltage range V.sub.f12 to V.sub.f13, a voltage range V.sub.f13 to V.sub.f14, a voltage range V.sub.f14 to V.sub.f15, a voltage range V.sub.f15 to V.sub.f16, a voltage range V.sub.fl6 to V.sub.f17 and a voltage range V.sub.f17 to V.sub.f2. Each voltage range has the same interval (to be V), as shown by the following equation:
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More specifically, the voltage range V.sub.f1 to V.sub.f11 corresponds to a digital code 000, the voltage range V.sub.f11 to V.sub.f12 corresponds to a digital code 001, the voltage range V.sub.f12 to V.sub.f13 corresponds to a digital code 010, the voltage range V.sub.f13 to V.sub.f14 corresponds to a digital code 011, the voltage range V.sub.f14 to V.sub.f15 corresponds to a digital code 100, the voltage range V.sub.f15 to V.sub.f16 corresponds to a digital code 101, the voltage range V.sub.f16 to V.sub.f17 corresponds to a digital code 110 and the voltage range V.sub.f17 to V.sub.f2 corresponds to a digital code 111. In the present embodiment, because it is schematically illustrated that the second voltage V.sub.S2 falls in the voltage range V.sub.f15 to V.sub.f16, the A/D converter 128 converts the voltage range V.sub.f15 to V.sub.f16 into the digital code 101. It is noted that the resolution during temperature measurement is increased when the interval V is decreased. Since the sub-voltage range SUBV is smaller than the first voltage range, the interval V.sub.S calculated from the sub-voltage range SUBV is smaller than the interval V.sub.1 that calculated from the first voltage range. Therefore, the resolution of MEMS apparatus with the range selector is higher than that the MEMS apparatus without the range selector. Next, the second calibration device 127 is configured to receive a digital code DC from the A/D converter 128 and calibrate the digital code DC according to the standard blackbody. The second processing device 125b can receive the calibrated digital code DC from the second calibration device 127 and can convert the calibrated digital code DC into temperature information T.sub.F. Further, in the present embodiment, a display (not illustrated) is further provided, and the second processing device 125b can transfer the temperature information to the display so the display can display the temperature information T.sub.F.
(31) In summary, in the MEMS apparatus having measuring range selector according to the embodiments of the present disclosure, the detecting device and the sensing device respectively generate the electrical signal and the sensing voltage according to the measured physical quantity. The voltage range selector selects the sub-voltage range from the first voltage range based on the sensor according to the electrical signal from the detecting device, such that the first voltage related to the sensing device is between the first upper-bound and the first lower-bound of the sub-voltage range. The control device in the IC chip adjusts the sub-voltage range to the full scale voltage range so the first voltage is also adjusted to the second voltage accordingly. Therefore, when the MEMS apparatus according to the embodiments of the present disclosure measures the temperatures in the different temperature ranges, the first voltage range with different sizes corresponding to the sensing device can all be adjusted to the same full scale voltage range. In this way, the MEMS apparatus according to the embodiments of the present disclosure can provide the identical or similar sensitivities when measuring the temperatures in different ranges.
(32) Next, according to the number of bits, the second A/D converter in the IC chip can further divide the full scale voltage range into a plurality of different voltage ranges. As a result, the MEMS apparatus according to the embodiments of the present disclosure can further determine the smaller temperature range from the sub-voltage range according to the second voltage, so as to provide the higher resolution during temperature measurement.
(33) From another perspective, because the smaller temperature range may be determined from the smaller subs-voltage range, the MEMS apparatus according to the embodiments of the present disclosure can accomplish the same resolution as that of the conventional temperature sensor which is equipped with the high bit A/D converter. Therefore, the MEMS apparatus according to the embodiments of the present disclosure can further reduce its cost.
(34) It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the present disclosure being indicated by the following claims and their equivalents.