Mixed compensating type high-stability LDO (low-dropout regulator) chip circuit

Abstract

The invention provides a mixed compensating type high-stability LDO (low-dropout regulator) chip circuit. The mixed compensating type high-stability LDO chip circuit comprises a differential input amplifier A1, a push-pull buffer amplifier A2, an integrated PMOS (p-channel metal oxide semiconductor) device P0, a resistor Rc, a resistor RF1, a resistor RF2, a capacitor Cc, a capacitor CFF, a chip output capacitor Cout, an equivalent series resistor Resr of the Cout and a chip output load Rload, and is characterized in that the A1 is in output connection with the A2, the Rc and the Cc are serially connected to be bridged at two ends of the A2, the A2 is in output connection with a grid electrode of the P0, a drain electrode of the P0 is an output end Vout and connected with one ends of the RF1, the Cout and the Rload, the RF1 and the RF2 are grounded in a series connection mode, the CFF is bridged at two ends of the RF1, an intersection of the RF1 and the RF2 is connected to an input negative terminal of the A1, the Cout and the Resr are grounded in a series connection mode, and the other end of the Rload is grounded. The mixed compensating type high-stability LDO chip circuit adopts ESR (equivalent series resistance) compensation, miller compensation and front feed-forward capacitance compensation, and stability of the LDO system is improved.

Description

technical field [0001] The invention relates to an LDO chip circuit, in particular to a high-stability LDO chip circuit using multiple compensation technologies, and belongs to the technical field of integrated circuits. Background technique [0002] Low-dropout linear stabilized voltage source, referred to as LDO, is a kind of stabilized voltage source, but compared with ordinary linear stabilized voltage sources, it has the characteristics of low dropout voltage and high conversion efficiency, and has broad application prospects in the field of power supply for portable electronic products. [0003] The key technical problem of LDO at present is the problem of loop stability. Since the LDO circuit uses PMOS as the output adjustment tube and adds a common source inverting amplifier, it has a high output impedance, so that the position of the output pole will vary with the load. Changes, the circuit stability is not high, and LDO is a closed-loop system, the low stability wi...

AI Technical Summary

Problems solved by technology

[0003] The key technical problem of LDO at present is the problem of loop stability. Since the LDO circuit uses PMOS as the output adjustment tube and adds a common source inverting amplifier, it has a high output impedance, so that the position of the output pole will vary with the load. Changes, the circuit stability is not high, and LDO is a closed-loop system, the low stability will directly cause the output voltage to oscillate and cannot be used, so it is urgent to perform strict frequency compensation on the LDO to meet its loop stability requirements

At present, the compensation for LDO loop stability is relatively simple at home and abroad, and the LDO with multiple compensation methods can well meet the frequency stability requirements.

Images