An AC/DC coupling circuit

Abstract

The invention provides an alternating current / direct current coupling circuit. The circuit comprises a differential input coupling control circuit, a common mode generation circuit and a boosted circuit, wherein the differential input coupling control circuit is configured to receive a pair of differential input signals and output a corresponding alternating current or direct current coupling signal based on a condition that the alternating current / direct current coupling circuit is in an alternating current coupled mode or a direct current coupled mode; the common mode generation circuit is coupled to the differential input coupling control circuit and is configured to generate a common mode voltage and provide the common mode voltage to the differential input coupling control circuit; and the boosted circuit is coupled to the differential input coupling control circuit and the common mode generation circuit and is configured to provide an additional voltage based on the common mode voltage to the differential input coupling control circuit so that the alternating current / direct current coupling circuit enters into the alternating current coupled mode. By using the alternating current / direct current coupling circuit, an existing voltage and a work clock are fully used to increase a grid voltage of a control switch, and an extra voltage or a device and an extra clock do not need to be introduced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an AC / DC coupling circuit. Background technique [0002] In the design of AC-DC coupling (ADC), in order to reduce the design complexity of the board, some circuits are often directly integrated into the chip. Both DC-coupled and AC-coupled inputs are common applications for ADCs, and their control is usually integrated into the ADC. Under advanced technology such as 28nm, using pure core voltage (such as 28HK, using 0.9V core voltage) for ADC design, on the one hand, can reduce the requirement for multiple power supplies, and at the same time adopt pure core device (core device) design Can increase the speed of the circuit. However, there are certain problems in the above design. In the circuit design powered by pure core voltage, the control switch of the ADC will not work properly because the core voltage is too low. [0003] At present, there are usually three solut...

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Problems solved by technology

However, there are certain problems in the above design. In the circuit design powered by pure core voltage, the control switch of the ADC will not work properly because the core voltage is too low.

[0003] At present, there are usually three solutions to the above problems: first, do not control the coupling circuit, which will cause a certain loading current at the input end, which will increase the power consumption of the coupling circuit; second, introduce a A power supply with a higher voltage group is used to supply power to the coupling switch. This method requires an additional group of power supplies, which has higher requirements for system design and will increase production costs. Third, design the control circuit on a single board. This method will increase Single board design duplication

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