AC-DC (alternating current-direct current) regulator with high-precision constant current output function
Patent Information
- Authority / Receiving Office
- CN ยท China
- Current Assignee / Owner
- WUXI ZGMICRO ELECTRONICS CO LTD
- Publication Date
- 2013-02-20
Smart Images
Figure 1 Figure 2 Figure 3
Abstract
Description
technical field
[0001] The invention relates to an AC-DC regulator with high precision constant current output. Background technique
[0002] In flyback AC-DC applications, it is sometimes necessary to implement a constant voltage constant current (CV / CC) characteristic for the secondary output. figure 1 A circuit for realizing constant current is shown, figure 2 signaled figure 1 The output waveform of the circuit. In practice, when the current limit signal (OCP) turns off the power transistor Q0, due to the existence of the desaturation time of the power transistor and the charging and discharging time of the parasitic capacitance (total Td), the inductor current of the main winding continues to rise, The secondary rectifier has current output until flyback. During this period of time, the actual peak value of the inductor current of the main winding is greater than the target value, and the desaturation time of the power tube varies with the difference of the device,...