Novel constant-output-current BUCK circuit

Abstract

The invention discloses a novel constant-output-current BUCK circuit which comprises the components of a current sensing resistor, wherein one end of the current sensing resistor is connected with a rectifying switch node, and the other end is connected with an output anode; an output capacitor of which one end is connected with the output anode and the other end is connected with an output cathode; a high-level switch which is connected with an input power supply anode and a rectifying switch node; a low-level switch which is connected with an input power supply cathode and the rectifying switch node; a first signal amplifying and translating module which generates a triangular wave signal; a second signal amplifying and translating module which generates a real-time current signal; and an average value calculating module which acquires an average current signal that represents an inductor average current value according to the real-time current signal. Compared with prior art, the novel constant-output-current BUCK circuit has advantages of settling a high-level switch matching problem, preventing cost increase and switching efficiency reduction by means of one current sensing resistor, ensuring high precision of output current, and preventing a problem of actual use performance reduction caused by factors of uncertain frequency, etc.

Description

technical field [0001] The invention belongs to the field of step-down DC-DC, and particularly relates to a novel constant output current BUCK circuit, which is used for converting higher voltage electric energy and inductance rectification into lower voltage electric energy and maintaining constant current output. Background technique [0002] In mobile phone charging and LED driving applications, power input with constant current function is often required, so the demand for DC-DC with constant current output function is increasing day by day, especially in mobile phone charging applications, the current demand is increasing, and High precision constant current is required. [0003] BUCK (BUCK circuit) is a kind of DC-DC, which is a non-isolated step-down DC-DC. BUCK has a high-precision constant current output function, but also has a wide range of applicability, stability and reliability, and low cost, which is very suitable for current industry needs, especially for ve...

AI Technical Summary

Problems solved by technology

[0022] In view of this, it is indeed necessary to provide a solution to the matching problem of the high-level switch. Only one current-sensing resistor is used to avoid the increase in cost and the decrease in conversion efficiency, and at the same time ensure the accuracy of the output current without frequency fluctuations. A new constant output current BUCK circuit to determine the problems that affect practical use

Images