Pre-emphasis circuit and low-voltage differential signal driver

Abstract

The invention discloses a pre-emphasis circuit and a low-voltage differential signal driver, and the pre-emphasis circuit comprises a pulse generation and control module which is configured to generate a pre-emphasis pulse signal according to an external input signal; the at least one charging and discharging path is configured to provide pre-emphasis current for the LVDS driving circuit in response to the pre-emphasis pulse signal and directly connect the pre-emphasis circuit to the ground; wherein the charging and discharging path comprises a first PMOS (P-channel Metal Oxide Semiconductor) tube, a second PMOS tube, a first NMOS (N-channel Metal Oxide Semiconductor) tube, a second NMOS tube, a first blocking unit and a second blocking unit. According to the pre-emphasis circuit, the current trap is introduced into the charging and discharging path, a path to the ground is provided for the working current of the pre-emphasis circuit, and common-mode interference caused by the pre-emphasis circuit is effectively reduced.

Description

technical field [0001] The invention relates to the technical field of data transmission, in particular to a pre-emphasis circuit and a low-voltage differential signal driver. Background technique [0002] As a high-speed serial data communication interface, the low-voltage differential signaling (LVDS) transmitter has been widely used in high-speed applications such as high-speed backplanes and processors, and is an important high-speed serial data interface. [0003] figure 1 A circuit diagram of a conventional low voltage differential signal transmitter is shown. Signals pp and nn are a group of differential signals. When nn is high level and pp is low level, current I0 flows through PMOS transistor MP0, resistor R0, NMOS transistor Mn1 and resistor R1 in turn; otherwise, it flows through PMOS transistor MP1 in turn. , resistor R0, NMOS tube Mn0 and resistor R1. These two cases will form a positive and negative voltage drop of Vout=I0*R0=3.5mA*100Ω=350mV on the resisto...

AI Technical Summary

Problems solved by technology

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a pre-emphasis circuit and a low-voltage differential signal driver, which are used to solve the problem of the pre-emphasis circuit when the low-voltage differential signal transmitter in the prior art transmits high-speed data signals. It will cause the deterioration of the common mode signal, and the higher the frequency of the transmission signal, the more serious the technical problem of the interference of the common mode signal

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