JPH0421361A - Half-wave rectifying circuit - Google Patents

Abstract

PURPOSE:To realize a high performance half-wave rectifying circuit having simple constitution by providing a comparator and first and second CMOS analog switches and to facilitate integration of circuit by reducing the number of diode and resistor elements. CONSTITUTION:Source terminals and drain terminals of an N-channel MOSFET 1 and a P-channel MOSFET 2 are connected respectively thus constituting a first CMOS analog switch 14. A second CMOS analog switch 15 is constituted in similar manner. Output terminal 13 of a comparator 10 is connected through inverters 5, 6 with the CMOS analog switch circuits 14, 15. Upon provision of an input signal VIN to the input terminal 11, the comparator 10 makes a judgment of polarity and conducts the CMOS analog switch 14 or 15 thus producing an output signal VOUT at the output terminal 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a half-wave rectifier circuit that is capable of low voltage operation, has good frequency characteristics, and is easy to integrate into an integrated circuit.

[Summary of the invention]

This invention uses a comparator and a CM in a half-wave rectifier circuit.
Rectification using an OS analog switch eliminates the need for diodes and resistors, improves frequency characteristics, enables low voltage operation, and facilitates integration into integrated circuits.

[Conventional technology]

In the conventional half-wave rectifier circuit, diodes 18 and 19,
The fourth rectifier is rectified using resistors 20 and 21 and an operational amplifier 17.
A circuit like the one shown in the figure was known. FIG. 5 is an input/output timing diagram of the half-wave rectifier circuit of FIG. 4.

[Problem to be solved by the invention]

However, when the half-wave rectifier circuit of the prior art is integrated into an integrated circuit using 0MO3 technology, a diode and a resistor must be connected outside the integrated circuit, which makes it difficult to integrate the circuit. Furthermore, since a connection terminal with a diode and a resistor is required, it is difficult to achieve high frequencies due to parasitic capacitance of wiring and the like. Furthermore, the operating voltage range is limited by the forward voltage drop of the diode, resulting in a high operating voltage. The present invention aims to solve the above-mentioned drawbacks of the conventional art by making it possible to operate at a low voltage and to facilitate integration into an integrated circuit.

[Means to solve the problem]

In order to solve the above conspiracy, this invention uses a comparator and C
I made it rectify with a MOS analog switch.

(Function) When a positive input signal is supplied to the half-wave rectifier circuit configured as described above, the first CMOS analog switch becomes conductive, the input signal is output from the output terminal, and the negative input signal When supplied, the second CMOS analog switch becomes conductive and the ground level is output to the output terminal, allowing the half-wave rectifier circuit to operate.

C Embodiment] Hereinafter, an embodiment of the present invention will be described in detail based on the drawings. In FIG. 1, a first CMOS analog switch 14 is configured by connecting the source terminals and drain terminals of an N-channel MO3FETI and a P-channel MO3FET2. Also, MO3FET3,
A second CMOS analog switch 15 is configured by connecting the source terminals and the drain terminals of the P-channel MOSFETs 4 to each other. A source terminal common connection point of the CMOS analog switch circuit 14 is connected to the non-inverting input terminal of the comparator 10 and the signal input terminal 11.

A common connection point between the source terminals of the CMOS switch circuit al15 is connected to the inverting input terminal of the comparator 10 and the ground terminal 12. CMOS analog switch circuit 14.
A common connection point of the 15 drain terminals is connected to the output terminal 9.

The output terminal 13 of the comparator IO is connected to the input terminal of the inverter 5, and the output terminal 7 of the inverter 5 is connected to the input terminal of the inverter 6, the gates of the P-channel MOSFET 2, and the N-channel MOS FET 3. The output terminal 8 of the inverter 6 is connected to the gates of the N-channel O8FET1 and the P-channel MO3FE74.

In the circuit configured as described above, the input signal VIN shown in FIG. 2 is input to the input terminal 11, and when the human input signal is in a positive half cycle, the CMOS analog switch 14 becomes conductive, and the output terminal 9 is connected to the input signal VIN shown in FIG. As shown by the output signal VOtlT, a positive voltage equal to the input signal is output. When the input signal is a negative half cycle, CMOS analog switch 1
5 becomes conductive, and the brand potential is output to the output terminal 9.

As can be seen from the above explanation, the positive/negative judgment is performed by a comparator, and the switching of the CMOS analog switches 14 and 15 is performed by an inverter, so high frequency operation is possible, and the output can be made up to almost the power supply voltage. Low voltage operation is possible.

In the embodiment shown in FIG. 1, the positive voltage half-wave rectifier circuit was explained as an example, but the input signal VIN shown in FIG. 3 can be applied by using terminal 11 as a ground terminal and terminal 12 as an input terminal. The output signal VO shown in FIG.
UT is output from output terminal 9 and becomes a negative voltage half-wave rectifier circuit.

〔Effect of the invention〕

As explained above, the present invention allows the first . A high-performance half-wave rectifier circuit can be obtained with a simple configuration of providing a second CMOS analog switch, and since there is no need for diodes or resistive elements, it is easy to integrate the circuit, so it is extremely effective in practical use. It's large.

[Brief explanation of drawings]

FIG. 1 is a circuit showing an embodiment of the half-wave rectifier circuit according to the present invention, FIG. 2 is an input/output timing diagram of the half-wave rectifier circuit of FIG. 1, and FIG. 3 is a diagram showing the half-wave rectifier circuit of FIG. 4 is a circuit diagram of a conventional half-wave rectifier circuit, and FIG. 5 is an input-output timing diagram of the half-wave rectifier circuit shown in FIG. 4. ...N channel field effect transistor...P channel field effect transistor...N channel field effect transistor...P channel field effect transistor 6...
・CMOS inverter ・Comparator ・Signal source ・Operation amplifier 18°19 ・Diode 20°21 ・・More than resistance

Claims (1)

[Claims] comprising first and third field effect transistors of a first conductivity type and second and fourth field effect transistors of a second conductivity type, the source terminals of the first and second field effect transistors are connected to each other, and the drain Connect the terminals in common and start the first CM
An OS analog switch is configured, and a second CMOS analog switch is configured by commonly connecting the source terminals and drain terminals of the third and fourth field effect transistors, and a non-contact switch of a comparator to which an input signal is supplied. An inverting input terminal is connected to a common source terminal of the first CMOS analog switch, an inverting input terminal of the comparator to which a ground level is supplied is connected to a common source terminal of the second CMOS analog switch, and the inverting input terminal of the comparator is connected to a common source terminal of the second CMOS analog switch. an output of the first inverter, an output of the first inverter connected to gates of the second and third field effect transistors and an input of the second inverter, and an output of the second inverter; is connected to the gates of the first and fourth field effect transistors, and the first CMO
The common drain terminal of the S analog switch and the second C
A half-wave rectifier circuit constructed by connecting the common drain terminals of MOS analog switches and using them as output terminals.