A charge pump circuit with self-calibration function and programmable current

Abstract

The invention discloses a charge pump circuit with self-calibration function and programmable current, comprising a current source switch array, a current source switch decoding circuit, a current sink switch array, a current sink switch decoding circuit and a calibration circuit; the current source switch The array and the current sink switch array are respectively connected to the output of the charge pump; the current source switch decoding circuit and the current sink switch decoding circuit respectively decode the control code input from the outside into the switch control signals of the current source switch array and the current sink switch array ; The calibration circuit automatically detects the current mismatch of the current source switch array and the current sink switch array, and realizes the self-calibration of the charge pump current mismatch. The invention solves the mismatching problem of the charging current and the discharging current of the charge pump caused by non-ideal factors such as process mismatch and channel modulation effect, and greatly improves the matching accuracy of the charging current and the discharging current of the charge pump.

Description

technical field [0001] The invention belongs to the technical field of digital-analog hybrid circuits such as high-speed digital-to-analog converters, radio frequency transceivers and frequency synthesizers, and in particular relates to a charge pump circuit with self-calibration function and programmable current. Background technique [0002] Military equipment such as wireless communication equipment and radar usually contain digital-analog hybrid circuits such as high-speed digital-to-analog converters, radio frequency transceivers, and frequency synthesizers. These circuits require high-speed clock signals, and the quality of clock signals directly affects system performance. The signal quality of the clock is critical. The high-performance high-speed clock is usually generated by a phase-locked loop circuit, and the charge pump is the key circuit of the phase-locked loop. The voltage ripple caused by the mismatch between the charging current and the discharging current ...

AI Technical Summary

Problems solved by technology

The high-performance high-speed clock is usually generated by a phase-locked loop circuit, and the charge pump is the key circuit of the phase-locked loop. The voltage ripple caused by the mismatch between the charging current and the discharging current of the charge pump will cause spurious problems in the clock signal; and the charge pump’s The magnitude of the current will directly determine the gain and bandwidth of the phase-locked loop circuit, and affect the noise performance and stability of the phase-locked loop circuit; however, due to the mismatch of the circuit production process, the temperature of the circuit working environment and the fluctuation of the power supply voltage will cause the charging current of the charge pump It does not match the discharge current; and, in the charge pump work project, the change of the charge pump output voltage Vo will affect the charge pump charge current and discharge current through the channel modulation effect

When the charge pump output voltage Vo increases, the charging current will decrease, while the discharge current will increase; when the charge pump output voltage Vo decreases, the charging current will increase, while the discharge current will decrease; these are due to process, temperature, power supply The mismatch of charge pump charging current and discharging current caused by factors such as voltage and channel modulation will directly limit the clock quality of the phase-locked loop circuit

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