Reference voltage regulation method and circuit as well as constant-current source driving circuit utilizing same

Abstract

The present invention relates to reference voltage regulating methods and circuits for a constant current driver. In one embodiment, a method can include: setting a reference voltage circuit matching with a current output channel of a constant current source; setting a first resistor of the reference voltage circuit to follow an ideal equivalent resistor of the current output channel, and maintaining a proportion of the first resistor and the ideal equivalent resistor to be no less than a predetermined value M; setting a first current of the reference voltage circuit to follow an ideal output current of the current output channel, and maintaining a proportion of the first current and the ideal output current to be no less than 1 / M; and setting a product of the first current and the first resistor to be a reference voltage of the reference voltage circuit.

Description

technical field [0001] The invention relates to the field of constant current source circuits, more specifically, to a reference voltage adjustment method and circuit for a constant current source drive circuit and a constant current source drive circuit using the same. Background technique [0002] In LED driving applications, in order to keep the LED light emission stable, a constant current source is often used to drive the LED. The constant current source used must have two characteristics: one is to maintain the output constant current characteristics as much as possible, and the other is to maintain a low self-loss, so that the system efficiency of the LED can be maintained at a high level. In order to meet the first characteristic, that is, to ensure that the output current of the constant current source is as constant as possible, the voltage value at both ends of the constant current source must meet the voltage value required by the constant current source for its ...

AI Technical Summary

Problems solved by technology

[0006] In view of this, the present invention provides a reference voltage adjustment method and circuit and its applied constant current source drive circuit to solve the problem that the current of the load LED is small, or the transistor technology in the constant current source is better and the equivalent resistance R HR Smaller, due to the fixed too high reference voltage V REF As a result, the power loss of the constant current source itself is large, thereby reducing the system efficiency of the LED, and realizing the reference voltage V of the constant current source REF Adaptive adjustment according to the change of current and resistance in the circuit

Images