Current-steering DAC circuit

Abstract

The invention provides a current-steering DAC circuit, which comprises a logic control circuit and a binary code DAC conversion circuit, wherein the logic control circuit is used for generating an N-bit binary code and an inverted code thereof according to a voltage pulse signal, corresponding bits in the binary code and the inverted code thereof form a group of mutually inverted switch control signals, and N is a positive integer greater than or equal to 1; the binary code DAC conversion circuit is connected to the logic control circuit and used for generating a reference current according to the reference voltage and mirroring the reference current to N current branches in proportion; and N pairs of switching tubes of N current branch circuits are respectively controlled through the N groups of switching control signals, so that when any binary code and the inverted code thereof are output, one switching tube in each pair of switching tubes is in an on state, and the other switching tube is in an off state, so that each current branch can be used as an output path or a discharge path. According to the current-steering DAC circuit, the problem that an existing current-steering DAC circuit has large output voltage burrs at the switching moment of a switch is solved.

Description

technical field [0001] The invention belongs to the field of integrated circuits, in particular to a current steering DAC circuit. Background technique [0002] In the LED driver chip circuit, sometimes a DAC conversion circuit is used to realize some digital to analog conversions. Currently, there are three types of current steering DAC structures commonly used in the industry, namely, binary code structure, temperature code structure, and segmented structure. Among them, the binary code structure has the advantages of simple structure and small area, but the disadvantage is that there are instantaneous glitches in the output when switching; The advantages of the code structure are good monotonicity and low requirements for matching accuracy, but the disadvantage is that the chip area consumes a lot; the segmented structure is a combination of binary code structure and temperature code structure. advantages and disadvantages of the Since the LED driver chip is not a speci...

AI Technical Summary

Problems solved by technology

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a current steering DAC circuit, which is used to solve the phenomenon that the existing current steering DAC circuit has a large output voltage glitch at the moment of switching, which leads to the failure of the LED driver chip. EMI interference, LED light flickering and other issues

Images