CN101667813A

CN101667813A - Pre-amplifier circuit

Info

Publication number: CN101667813A
Application number: CN200810154719A
Authority: CN
Inventors: 戴宇杰; 吕英杰; 张小兴; 孙俊岳
Original assignee: TIANJIN QIANGXIN IC DESIGN CO Ltd
Current assignee: TIANJIN QIANGXIN IC DESIGN CO Ltd
Priority date: 2008-12-30
Filing date: 2008-12-30
Publication date: 2010-03-10

Abstract

The invention discloses a pre-amplifier circuit, which comprises a transistor NMOS3, a transistor NMOS4 and a transistor NMOS5 and is characterized in that: loads of the pre-amplifier circuit comprisea transistor NMOS1 and a transistor NMOS2. The pre-amplifier circuit has the following advantages that: 1, the load properties of the circuit are influenced little by semiconductor process and temperature change, the range of working input common mode voltage is wide, the signal transmission speed is high, and the gain multiple is relatively stable; 2, the circuit has a simple structure, easy implementation and high reliability; and 3, the circuit is applicable to signal transmission and amplification of each part of the complex circuit.

Description

Pre-amplifier circuit

(1) technical field:

The present invention relates to a kind of amplifier circuit, especially a kind of pre-amplifier circuit.

(2) background technology:

At present, in the high speed signal transfer system, the loadtype of pre-amplifier circuit has two kinds usually: (1) is circuit as shown in Figure 1, directly use the load of resistance as circuit, the quick action of sort circuit, gain multiple height, but along with semiconductor technology and variation of temperature, the variation of resistance value is very big, promptly be difficult to guarantee the absolute precision of resistance, therefore, as shown in Figure 2, the mobility scale of circuit characteristic is also very big, directly has influence on the qualification rate of circuit; (2) circuit as shown in Figure 3, use of the load of the diode structure of transistor PMOS as circuit, although the ratio of gains of sort circuit is higher, but the input voltage range of energy operate as normal is narrow under high frequency condition, as shown in Figure 4, so in the signal amplification circuit wide to common-mode input voltage range, this structure just is difficult to satisfy actual requirement.

(3) summary of the invention:

The object of the present invention is to provide a kind of pre-amplifier circuit that uses the diode structure of transistor NMOS as load, the load characteristic of sort circuit is subjected to semiconductor technology and influence of temperature variation very little, the common mode input wide ranges of work, signal velocity is fast, and the gain multiple is also relatively stable.

Technical scheme of the present invention: a kind of pre-amplifier circuit, comprise transistor NMOS3, transistor NMOS4 and transistor NMOS5, the load that it is characterized in that pre-amplifier circuit is transistor NMOS1 and transistor NMOS2; Wherein, transistor NMOS3 and transistor NMOS5 are as differential input end of amplifier circuit; The grid of said transistor NMOS5 connects bias voltage, and by the direct current of bias-voltage generating circuit action, the source electrode of transistor NMOS5 is ground connection then; The grid of the grid of said transistor NMOS1 and drain electrode and transistor NMOS2 links to each other with power supply respectively with drain electrode; The source electrode of the drain electrode of said transistor NMOS1 and transistor NMOS3 links to each other with reversed-phase output of amplifier circuit respectively; The source electrode of the drain electrode of said transistor NMOS2 and transistor NMOS4 links to each other with the positive output end of amplifier circuit; The grid of said transistor NMOS3 links to each other with the normal phase input end of amplifier circuit; The grid of said transistor NMOS4 links to each other with the reversed input terminal of amplifier circuit; The source electrode of said transistor NMOS3 links to each other with the source electrode of transistor NMOS4 and the drain electrode of transistor NMOS5; The substrate of the substrate of the substrate of the substrate of the substrate of said transistor NMOS1, transistor NMOS2, transistor NMOS3, transistor NMOS4 and transistor NMOS5 links to each other with ground respectively.

A kind of application of pre-amplifier circuit is characterized in that it is applicable to that the signal at each position of complicated circuit transmits and amplification.

The application of above-mentioned said a kind of pre-amplifier circuit is applicable to that the signal at each position of complicated circuit transmits and amplifies and comprises and be applicable to high speed signal transmission, constant gain multiple, the signal transfer system that the common mode input scope is wide.

Operation principle of the present invention: satisfy the requirement of circuit when input signal, behind the positive and reversed input terminal input of differential input end, signal will be exaggerated certain multiple, and be sent to subsequent conditioning circuit at a high speed, thereby play the function that input signal is amplified and transmits from positive and reversed-phase output.

Superiority of the present invention is: 1, the load characteristic of sort circuit is subjected to semiconductor technology and influence of temperature variation very little, the common mode input wide ranges that can work, and signal velocity is fast, and the gain multiple is also relatively stable; 2, circuit structure is simple, is easy to realize the reliability height; 3, the signal that is applicable to each position of complicated circuit transmits and amplification.

(4) description of drawings:

Fig. 1 uses the circuit diagram of resistance as the pre-amplifier circuit of circuit load in the prior art.

Amplitude-frequency characteristic variation diagram when Fig. 2 is changed by flow-route and temperature for circuit among Fig. 1.

Fig. 3 uses the circuit diagram of the diode structure of transistor PMOS as the pre-amplifier circuit of circuit load in the prior art.

Amplitude-frequency characteristic variation diagram when Fig. 4 is changed by common mode input for circuit among Fig. 3.

Fig. 5 is the circuit diagram of the related a kind of pre-amplifier circuit of the present invention.

Amplitude-frequency characteristic variation diagram when Fig. 6 is changed by flow-route and temperature for the related a kind of pre-amplifier circuit of the present invention.

Amplitude-frequency characteristic variation diagram when Fig. 7 is changed by common mode input for the related a kind of pre-amplifier circuit of the present invention.

(5) embodiment:

Embodiment: a kind of pre-amplifier circuit (see figure 5), comprise transistor NMOS3, transistor NMOS4 and transistor NMOS5, the load that it is characterized in that pre-amplifier circuit is transistor NMOS1 and transistor NMOS2; Wherein, transistor NMOS3 and transistor NMOS5 are as differential input end of amplifier circuit; The grid of said transistor NMOS5 connects bias voltage, and by the direct current of bias-voltage generating circuit action, the source electrode of transistor NMOS5 is ground connection then; The grid of the grid of said transistor NMOS1 and drain electrode and transistor NMOS2 links to each other with power supply respectively with drain electrode; The source electrode of the drain electrode of said transistor NMOS1 and transistor NMOS3 links to each other with reversed-phase output of amplifier circuit respectively; The source electrode of the drain electrode of said transistor NMOS2 and transistor NMOS4 links to each other with the positive output end of amplifier circuit; The grid of said transistor NMOS3 links to each other with the normal phase input end of amplifier circuit; The grid of said transistor NMOS4 links to each other with the reversed input terminal of amplifier circuit; The source electrode of said transistor NMOS3 links to each other with the source electrode of transistor NMOS4 and the drain electrode of transistor NMOS5; The substrate of the substrate of the substrate of the substrate of the substrate of said transistor NMOS1, transistor NMOS2, transistor NMOS3, transistor NMOS4 and transistor NMOS5 links to each other with ground respectively.

The present invention is compared with the prior art:

Fig. 6 shows the influence to the amplitude-frequency characteristic of pre-amplifier circuit of the present invention of semiconductor technology and variation of temperature, compare with the characteristic curve of Fig. 2, it is much smaller as the influence of the pre-amplifier circuit of load that the characteristic of visible circuit of the present invention will be compared common use resistance.

Fig. 7 shows that common mode input changes the influence to the amplitude-frequency characteristic of pre-amplifier circuit of the present invention, compare with the characteristic curve of Fig. 4, the common mode input scope of visible circuit of the present invention is wider as the common mode input scope of the pre-amplifier circuit of load than the diode structure of common use transistor PMOS.

Claims

1, a kind of pre-amplifier circuit comprises transistor NMOS3, transistor NMOS4 and transistor NMOS5, and the load that it is characterized in that pre-amplifier circuit is transistor NMOS1 and transistor NMOS2; Wherein, transistor NMOS3 and transistor NMOS5 are as differential input end of amplifier circuit; The grid of said transistor NMOS5 connects bias voltage, and by the direct current of bias-voltage generating circuit action, the source electrode of transistor NMOS5 is ground connection then; The grid of the grid of said transistor NMOS1 and drain electrode and transistor NMOS2 links to each other with power supply respectively with drain electrode; The source electrode of the drain electrode of said transistor NMOS1 and transistor NMOS3 links to each other with reversed-phase output of amplifier circuit respectively; The source electrode of the drain electrode of said transistor NMOS2 and transistor NMOS4 links to each other with the positive output end of amplifier circuit; The grid of said transistor NMOS3 links to each other with the normal phase input end of amplifier circuit; The grid of said transistor NMOS4 links to each other with the reversed input terminal of amplifier circuit; The source electrode of said transistor NMOS3 links to each other with the source electrode of transistor NMOS4 and the drain electrode of transistor NMOS5; The substrate of the substrate of the substrate of the substrate of the substrate of said transistor NMOS1, transistor NMOS2, transistor NMOS3, transistor NMOS4 and transistor NMOS5 links to each other with ground respectively.

2, a kind of application of pre-amplifier circuit is characterized in that it is applicable to that the signal at each position of complicated circuit transmits and amplification.

3, according to the application of the said a kind of pre-amplifier circuit of claim 2, the application that it is characterized in that said a kind of pre-amplifier circuit is applicable to that the signal at each position of complicated circuit transmits and amplifies and comprises and be applicable to high speed signal transmission, constant gain multiple, the signal transfer system that the common mode input scope is wide.