Differential delay circuit, voltage-controlled delay line tuning circuit and chip

Abstract

The invention provides a differential delay circuit for a voltage-controlled delay line, a voltage-controlled delay line tuning circuit and a chip. The differential delay circuit for the voltage-controlled delay line comprises a pair of differential input transistors, a voltage signal input unit, a resistance adjusting unit and a cross coupling unit. The resistance adjusting unit and the voltage signal input unit are arranged in parallel, and the resistance adjusting unit is connected with the control circuit and adjusts the load of the resistance adjusting unit according to the load control signal generated by the control circuit so as to adjust the tuning range of the voltage-controlled delay line. According to the technical scheme provided by the embodiment of the invention, the load ofthe differential delay circuit is adjusted by adjusting the conduction and cut-off of the plurality of PMOS tubes in the PMOS tube array, so that the tuning range of the voltage-controlled delay lineis expanded, and the circuit operates more stably and safely.

Description

technical field [0001] The invention relates to a delay circuit structure, in particular to a differential delay circuit, a voltage-controlled delay line tuning circuit and a chip. Background technique [0002] DDR (Double Data Rate, double rate synchronous dynamic random access memory) is SDRAM (Synchronous Dynamic Random Access Memory, synchronous dynamic random access memory) with double transfer rate, its transfer speed is twice the system clock, due to the speed increase, Its transmission performance is better than traditional SDRAM. In the DDR memory system, the voltage-controlled delay line is the main component of the delay line circuit of the delay-locked loop. The voltage-controlled delay line circuit realizes that the analog voltage signal generated by the charge pump controls the output of the delay-locked loop, so as to delay the output of the electrical signal for a period of time. The circuit design of the voltage-controlled delay line mostly uses a pseudo-d...

AI Technical Summary

Problems solved by technology

In the circuit structure, active load control is usually used to expand the tuning range, but simple load adjustment cannot achieve the desired effect, and it cannot guarantee that a wide tuning range can be obtained under different input frequencies.

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