High-gain and low-noise differential trans-impedance amplifier

A transimpedance amplifier and low-noise technology, applied in the field of high-gain and low-noise differential transimpedance amplifiers, can solve problems such as small bandwidth, high noise, and insufficient gain, and achieve fewer tubes, reduced power consumption, and reduced chip area Effect

CN104113293AActive Publication Date: 2014-10-22XIDIAN UNIV
4 Cites 19 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2014-10-22

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a high-gain and low-noise differential trans-impedance amplifier. The high-gain and low-noise differential trans-impedance amplifier comprises a current mirror, an adjusting type common-emitter and common-base trans-impedance amplifier and an output common-source amplifier, wherein the adjusting type common-emitter and common-base tarns-impedance amplifier comprises a common-base amplifying unit and a negative feedback common-emitter amplifying unit; the negative feedback common-emitter amplifying unit is arranged between an emitter and a base of the common-base amplifying unit and serves as a negative feedback channel; input current is copied by the current mirror in an equal proportion manner; the current mirror provides bias voltage for the common-base amplifying unit and the negative feedback common-emitter amplifying unit; the output common-source amplifier is connected between an output end of the adjusting type common-emitter and common-base trans-impedance amplifier and an output end of the high-gain and low-noise differential trans-impedance amplifier; and trans-impedance gain is increased. By the high-gain and low-noise differential tarns-impedance amplifier, received weak signals are amplified in a high-gain and low-noise manner, bandwidth is large, and a dynamic range of inputted current signals are reasonably set; and the high-gain and low-noise differential tarns-impedance amplifier has the advantages of easiness in design and monolithic integration.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the field of integrated circuits, in particular to a high-gain, low-noise differential transimpedance amplifier. Background technique

[0002] In fiber optic communication systems, preamplifiers have a significant impact on the performance of the entire system, such as speed, sensitivity, and signal-to-noise ratio. According to the characteristics of the bias resistor, there are three optional preamplifiers: low impedance amplifier, transimpedance amplifier and high impedance amplifier. Low-impedance amplifiers have simple structure and large bandwidth, but the gain is not high enough, and the noise is large, while high-impedance amplifiers have high sensitivity and low noise, but have the disadvantages of small bandwidth and narrow dynamic range. Choosing a transimpedance amplifier can meet these performance requirements A good compromise was achieved.

[0003] Such as figure 1 Shown is the structure diagram of the current-...

Examples

Embodiment Construction

[0044] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

[0045] Such as figure 2 Shown is the circuit diagram of the RGC (Regulated-Cascade, adjusted cascode) transimpedance amplifier.

[0046] exist figure 2 Among them, Vdd is the power supply voltage, gnd is the ground terminal, I in is the input current signal, C D is the photodetector parasitic capacitance, V out is the output voltage signal;

[0047] and figure 1 Compared with the current-mode form transimpedance amplifier structure shown, figure 2 The RGC transimpedance amplifier shown adds the NMOS transistor M B and resistor R B A common source amplifier is used as a negative feedback path, and the NMOS transistor M 1 Provide bias voltage; if M 1 The drain-source current increases, the resistor R S The voltage drop increases, that is, the...