Constant current constant voltage power controller and encapsulation and supply converter thereof

Abstract

The invention discloses a constant current constant voltage power controller and a supply converter thereof. The constant current constant voltage power controller comprises three pins: a supply pin VDD, a switch control pin GATE and a ground pin GND, wherein the GND ground pin is connected with a resistor RS, and the GATE pin and the GND pin are connected with a switch tube T1; the power controller further comprises a voltage difference detection module, a secondary pole detection module, a constant voltage constant current control module and a driving stage module, wherein the voltage difference detection module detects the voltage difference between the VDD pin and the GND pin when the switch tube T1 is turned on and cut off; the secondary pole detection module clamps the voltage of theGATE pin when the switch tube T1 is cut off so as to enable the voltage to be smaller than the breakover threshold voltage of the switch tube T1, and at the same time, the secondary pole detection module detects the current passing through the GATE pin so as to further detect the secondary output voltage and the secondary demagnetization pulse width. The invention can reduce the system cost of aflyback converter. In addition, the invention also provides a pin multiplexing method, and therefore, the cost of a control chip of the flyback converter can be greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit design, and relates to a power controller, in particular to a constant current and constant voltage power controller and its package; in addition, the invention also relates to a power converter including the above constant current and constant voltage power controller . Background technique [0002] Power converters are essential components in electronic systems. As we all know, power converters include two main types, linear converters and switching power converters, and can be divided into two types: isolated and non-isolated in terms of conversion methods. Switching power converters can achieve high conversion efficiency, so they are widely used in medium to high power applications, while in low power applications, especially systems below a few watts, linear converters are the mainstay. In recent years, switching power converters have gradually replaced linear converters in curre...

AI Technical Summary

Problems solved by technology

[0020] Figure 4 The architecture has a disadvantage: the on-resistance of SW1 needs to be accurately corrected, which brings great difficulty to this design. At the same time, the on-resistance of SW1 varies greatly with temperature, so the system CC accuracy is greatly affected

[0023] Figure 5 The architecture has a disadvantage: the matching of M1 and M2, and Rs need to be precisely corrected

Otherwise, there will be errors in the detection of the current flowing through Np, which will seriously affect the CC accuracy of the system

in addition Figure 5 The structure of the built-in pass transistor M2 will generate heat, so that the power range of its application is very small

[0024] To sum up, so far, the primary side control chip either has a large number of pins, which greatly increases the cost of chip packaging, or although the number of pins is small, the current detection resistor is built into the chip, which varies greatly with temperature and process. The accuracy of the CC point is not high, and the power range of the chip application will be limited due to the heating of the detection resistor

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