Circuit for current multiplication and division operation

Abstract

The utility model discloses a circuit for current multiplication and division operation, which relates to the technical field of integrated circuits and comprises an NPN type triode Q1, an NPN type triode Q2, an NPN type triode Q3 and an NPN type triode Q4. Collector electrodes of the Q1, the Q2 and the Q3 are all connected with a power supply; emitting electrodes of the Q1, the Q2, the Q3 and the Q4 are grounded; the base electrode of the Q1 is electrically connected with the emitter electrode of the Q2; the base electrode of the Q2 is connected with the base electrode of the Q3; the base electrode of the Q4 is electrically connected with the emitting electrode of the Q3; the collector electrode of the Q4 is connected with the mirror current module; the mirror current module is used for outputting current IOUT; the circuit utilizes logarithmic characteristics between collector currents and base and emitter voltages of the four triodes to realize multiplication and division operation between analog currents through addition and subtraction operation between the base and emitter voltages of the four triodes, and the circuit is simple in structure, low in power consumption, high in speed and suitable for application scenes with low precision requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of integrated circuits, and particularly relates to a circuit for current multiplication and division operation. BACKGROUND

[0002] A conventional method for realizing multiplication and division operation of analog signals is to convert analog signals into digital signals through an analog-to-digital converter (ADC), and then to complete multiplication and division operation by using a digital multiplier and divider. Although this method has high operation precision, it has problems of large power consumption and slow speed. In an operation with low precision requirement, an analog multiplier and divider can be used to achieve fast speed, reduce power consumption and circuit complexity.

[0003] At present, analog multipliers and dividers are mainly realized by two methods. One method is to use high gain of a current-mode amplifier to achieve relatively accurate multiplication and division result, but this method has large power consumption. The other method is to use unique square characteristics of a complementary metal oxide semiconductor (CMOS) or exponential characteristics in a sub-threshold region, but due to the working region limitation of a transistor itself, the operation range of this method is small, resulting in poor operation precision. SUMMARY

[0004] In view of the problems of small operation range and large power consumption in the prior art, the present application provides a circuit for current multiplication and division operation. The logarithmic characteristics between collector current and base-emitter voltage of a bipolar junction transistor (BJT) are used to realize multiplication and division operation between analog currents through addition and subtraction operation between base-emitter voltages of the BJT, so as to solve the problems in the prior art.

[0005] The circuit for current multiplication and division operation comprises an NPN-type bipolar junction transistor (BJT) Q1, an NPN-type BJT Q2, an NPN-type BJT Q3 and an NPN-type BJT Q4.

[0006] The Q1, Q2 and Q3 are connected with a power supply. The emitters of the Q1, Q2, Q3 and Q4 are grounded. The base of the Q1 is electrically connected with the emitter of the Q2. The base of the Q2 is connected with the base of the Q3. The base of the Q4 is electrically connected with the emitter of the Q3. The collector of the Q4 is connected with a mirror current module. The mirror current module is used to output a current IOUT.

[0007] Further, the mirror current module comprises a P-type metal oxide semiconductor (MOS) PM1 and a P-type MOS PM2. The sources of the PM1 and PM2 are connected with the power supply. The gate of the PM1 is electrically connected with the gate of the PM2. The collector of the Q4 is connected with the drain of the PM1 and between the gate of the PM1 and the gate of the PM2. The drain of the PM2 is connected with a current output end.

[0008] Further, a diode D1 is further included, a positive electrode of the D1 is connected with a base of the Q2 and a base of the Q3, and a negative electrode of the D1 is electrically connected to a collector of the Q1.

[0009] The utility model provides a circuit for current multiplication and division operation has the following beneficial effects:

[0010] The circuit utilizes the logarithmic characteristic between the collector current of four triodes and the base-emitter voltage, and after the addition and subtraction operation between the base-emitter voltage of four triodes, the base-emitter voltage in the operation is replaced by the collector current, so that the multiplication and division operation between analog currents is realized, compared with the traditional analog multiplier-divider circuit, the circuit has simple structure, low power consumption and high speed, and is suitable for application scenes with low precision requirement. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The utility model discloses a circuit structure diagram for current multiplication and division operation in the embodiment. DETAILED DESCRIPTION

[0012] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments.

[0013] The utility model discloses a circuit for current multiplication and division operation, utilizes the logarithmic characteristic between the collector current of triode BJT and base-emitter voltage, and realizes the multiplication and division operation between analog currents through the addition and subtraction operation between BJT base-emitter voltage.

[0014] The current multiplication and division operation circuit structure is as follows: Figure 1As shown, including NPN type triode Q1, NPN type triode Q2, NPN type triode Q3, NPN type triode Q4, diode D1, P type MOS PM1 and PM2, and input current I1, I2, I3 and output current IOUT; diode D1 is used to provide bias for triode Q2 and Q3. The specific connection relationship is: the collector of NPN type triode Q1 and the negative electrode of diode D1 are connected with input current I1, the base of NPN type triode Q1, the emitter of NPN type triode Q2 are connected with input current I2, the base of NPN type triode Q2, the base of NPN type triode Q3 are connected with the positive electrode of diode D1, the collector of NPN type triode Q2, the collector of NPN type triode Q3 are connected with power supply VDD, the emitter of NPN type triode Q3, the base of NPN type triode Q4 are connected with input current I3, the collector of NPN type triode Q4 is connected with the gate of P type MOS PM1, the drain of P type MOS PM1 and the gate of P type MOS PM2, the emitter of NPN type triode Q1, the emitter of NPN type triode Q4 are connected with ground GND, the source of P type MOS PM1, the source of P type MOS PM2 are connected with power supply VDD, the drain of P type MOS PM2 is connected with output current IOUT.

[0015] The working principle is: the collector current I C and the base-emitter voltage V BE The relationship between the base-emitter voltage V

[0016]

[0017] Where, I S is the saturation current of the triode, and VT is the thermal voltage.

[0018] The four NPN type triodes Q1, Q2, Q3 and Q4 in the circuit have:

[0019] V BE1 +V BE2 =V BE3 +V BE4

[0020] Where, V BE1 , V BE2 , V BE3 , V BE4 are the base-emitter voltages of triodes Q1, Q2, Q3 and Q4 respectively. Replace the base-emitter voltage in the formula with the collector current, and copy the collector current I4 of NPN type triode Q4 through PMOS current mirror, the output current IOUT expression is:

[0021]

[0022] Compared with a traditional analog multiplication and division circuit, the utility model has simple structure, low power consumption and high speed, and is suitable for application scenes with low precision requirement.

[0023] The above is only the preferred specific implementation of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the utility model within the technical range disclosed by the utility model, and all of them should be covered in the protection scope of the utility model.

Claims

1. A circuit for current multiplication and division, characterized by The mirror current module comprises a P-type MOS tube PM1 and a P-type MOS tube PM2; the source of the PM1 and the PM2 is connected with a power supply, the gate of the PM1 and the gate of the PM2 are electrically connected; the collector of the Q4 is connected to the drain of the PM1 and between the gate of the PM1 and the gate of the PM2 respectively; the drain of the PM2 is connected with a current output end. The mirror current module comprises a P-type MOS tube PM1 and a P-type MOS tube PM2; the source of the PM1 and the PM2 is connected with a power supply, the gate of the PM1 and the gate of the PM2 are electrically connected; the collector of the Q4 is connected to the drain of the PM1 and between the gate of the PM1 and the gate of the PM2 respectively; the drain of the PM2 is connected with a current output end.

2. The circuit for current multiplication / division according to claim 1, wherein, Further comprising a diode D1, the anode of the D1 is connected with the base of the Q2 and the base of the Q3, and the cathode of the D1 is electrically connected to the collector of the Q1.

3. The circuit for current multiplication / division operation according to claim 1, wherein, ​

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