Switching voltage stabilization circuit and voltage feedback circuit as well as voltage feedback method of voltage feedback circuit

Abstract

The invention discloses a switching voltage stabilization circuit and a voltage feedback circuit as well as a voltage feedback method of the voltage feedback circuit. The switching voltage stabilization circuit comprises a switching circuit for converting input voltage into output voltage and output current; the voltage feedback circuit comprises a resistance voltage sharing circuit for sampling the output voltage, a line loss detection circuit and a controlled current source circuit; a compensation control signal is supplied to the output end of the line loss detection circuit and is in direct proportion to the output current; the controlled current source circuit is provided with a control end, a grounding end and an output end; the control end is coupled to the output end of the line loss detection circuit and receives the compensation control signal; the grounding end is grounded; the output end supplies compensation current; and the output end of the resistance voltage sharing circuit is connected with the output end of the controlled current source circuit to supply feedback voltage which represents backward output voltage.

Description

technical field [0001] The invention mainly relates to a switching power supply, and more particularly relates to a switching voltage stabilizing circuit with a line loss compensation function, a voltage feedback circuit and a voltage feedback method thereof. Background technique [0002] Today, most electronic devices require switching power supplies to provide DC voltage to power them. When the switching power supply supplies power to the load, the sampling of the output voltage is used as the feedback voltage of the control circuit, and after the error amplification of the feedback voltage, the turn-on and turn-off time of the switch tube is adjusted to achieve a constant output voltage. However, when the output wire is long or the wire diameter is small, the output wire between the switching power supply and the load has a large line resistance (such as in the charger solution), and the output current will generate a large voltage when it flows through the output wire. ...

AI Technical Summary

Problems solved by technology

However, when the output wire is long or the wire diameter is small, the output wire between the switching power supply and the load has a large line resistance (such as in the charger solution), and the output current will generate a large voltage when it flows through the output wire. Line loss voltage drop

Moreover, when the output current changes greatly, the output voltage behind the output line will also change greatly, which will affect the normal operation of the load.

In constant voltage output mode, this variation is unacceptable in some occasions

Images