KR940012846A - Signal processing circuit of micro integrated moisture sensor - Google Patents

Abstract

The present invention relates to a signal processing circuit of a micro integrated humidity sensor, comprising: a reference capacitance setting unit for setting a reference capacitance in accordance with an output signal from a controller, and a reference capacitance setting unit in accordance with an output signal from the controller; A capacitance calculation unit for charging a charge or discharging the charge to the reference capacitance setting unit, and the reference voltage according to the reference capacitance of the reference capacitance setting unit and the capacitance calculating unit according to an output signal from the controller. Comprising a comparison unit for comparing the voltage according to the capacitance, the reference capacitance setting unit, the capacitance calculation unit and the controller for outputting the drive signal and the output signal of the comparator, respectively, and outputs the data .

Therefore, since the signal processing circuit directly displays the relative humidity, it does not need an additional circuit for a separate operation and has an advantage that it can directly interface with the LED display device and the PC.

Description

Signal processing circuit of micro integrated humidity sensor

Since this is an open matter, no full text was included.

2 is a signal processing circuit diagram of the micro integrated humidity sensor of the present invention;

3 is a flowchart for explaining the signal processing operation of FIG.

4 is an equivalent circuit diagram of FIG. 2 in an initialization step.

Claims (6)

Output signal from controller (CON) (ø, ø _1, ø ₂ ) and inverted output signal ( A reference capacitance setting unit (10) for establishing the reference capacitance according to Output signal (ø _R ) and inverted output signal from the controller (CON) The capacitance setting unit 20 for discharging the charge to the reference capacitance setting unit 10 or receiving and charging the charge from the reference capacitance setting unit 10, and from the controller CON. Output signal (ø _R ) and inverted output signal ( A comparison unit 30 for comparing the voltage according to the capacitance of the capacitance calculating unit 20 with the voltage according to the reference capacitance of the reference capacitance setting unit 10, and the reference capacitance setting unit 10, the driving signals ø, ø _1, ø _{2, and} ø _R are respectively output to the capacitance calculating section 20 and the comparing section 30, and the output signal Q of the comparing section 30 is input. And a controller (CON) for outputting the output data. 2. The reference capacitance setting unit (10) according to claim 1, wherein the reference capacitance setting unit (10) is an analog switch (SA _21- SA ₂₂ ) driven by an output signal (?) From the controller (CON), and inverted from the controller (CON). Output signal The analog switches SA _{25 and} SA ₂₆ driven by the "), the analog switches SA ₃₀ driven by the output signal ø ₁ from the controller CON, and the output signals from the controller CON. The reference capacitance is charged by charging an electric charge according to the reference voltage V _S according to the driving of the analog switch SA ₃₀ driven by ø ₂ and the analog switches SA _21, SA _23, SA ₂₅ . A capacitor (C _S ) for setting a voltage and a capacitor (CC _χ ) for charging a charge according to a reference voltage (V _χ ) according to the driving of the analog switches (SA _22, SA _23, SA ₂₆ ) and And a capacitor (C _R ) for charging electric charges according to a reference voltage (V _R ) according to the driving of the analog switches (SA _23, SA _29, SA ₃₀ ). Signal processing circuit. The method of claim 1, wherein the capacitance calculating section 20 is the inverted output signal from the controller (CON) ( Of the analog switches SA ₂₇ driven by the &_lt; _{RTI ID} = 0.0 _> ), &_lt; / _RTI &_gt; the analog switches SA ₃₁ driven by the output signal ø _R from the controller CON, and the analog SAs _{27 and} SA ₃₁ . capacitors for cycle by discharging the driving when the capacitor charge to _{(C S, C X, C} R) to charge the charge (Q _acc) or the capacitor (C _S, C _X) from the (Q _ext) (C _F) Signal processing circuit of the ultra-small integrated humidity sensor comprising a. 2. The comparison unit 30 according to claim 1, wherein the comparing unit 30 comprises: an analog switch SA ₂₄ driven by an output signal ø from the controller CON, and an inverted output signal from the controller CON. Analog switch (SA ₂₈ ) driven by the drive, analog switch (SA ₃₂ ) driven by the output signal (Q _R ) from the controller (CON), offset voltage compensation capacitor (C _C ), The reference voltage (V _R ) is the input signal of the non-inverting (+) terminal, and the capacitor (C _C ) is connected to the inverting (-) terminal, and its output (V _O ) is connected to the holding capacitor (C _H ). Anal the switch (SA ₂₄₎ and analog switch (SA ₃₂₎ the output signal (V _O) of the operational amplifier (OP ₂₁₎ and the operational amplifier (OP ₂₁₎ for to give each feedback inverted over (-) And an operational amplifier (OP ₂₂ ) for outputting the signal (Q) using the input signal of the terminal and the reference voltage (V _R ) as the input signal of the non-inverting (+) terminal. Signal processing circuit. The charge amount charged in the capacitor C _S is Q _S , and the charge amount charged in the capacitor C _X is Q _{X 1} and the charge amount charged in the capacitor C _R is Q _R , respectively. And setting the value of voltage (V _S, V _X, V _R ) such that the charge amount (Qacc) charged in the capacitor (C _F ) satisfies the following equation. The method of claim 3, wherein the capacitor (C _S) to the charge amount to be charged C _S La and capacitor an amount of electric charges charged in the (C _X), respectively, when considered Q _X, the capacitor (C _F) which is the amount of charge (Q _ext discharged from the ) A signal processing circuit for a micro integrated humidity sensor, characterized in that the value of the capacitors (C _S, C _x ) is set to satisfy the following equation. Q _ext = Q _x -Q _S > 0 ※ Note: The disclosure is based on the initial application.