Special design solutions and features for integrated switching power supplies
Compared with the traditional switching power supply, special integrated switching power supply has the characteristics of novel circuit, peculiar function, advanced performance and wider application fields. Common special integrated switching power supply usually use monolithic switching power supply integrated circuits, coupled with the corresponding peripheral circuits (including control loops) designed to have different output characteristics and application areas, to meet the needs of different users.
Special integrated switching power supply mainly includes the following five types:
(1) Composite switching power supply;
(2) Constant voltage / constant current (CV / CC) type switching power supply;
(3) cut-off current output type switching power supply;
(4) constant power output type switching power supply;
(5) other special switching power supply, such as high-speed modem (HighSpeedModem) power supply, DVD power supply.
Special integrated switching power supply design solutions and features
Special monolithic switching power supply has two design schemes: the first is the use of general-purpose monolithic switching power supply integrated circuits (e.g., TOpSwitch-II, TOpSwitch-FX, TOpSwitch-GX, and other series), and then with the voltage control loop, current control loop and other Peripheral circuits designed, which is characterized by higher output power, but the peripheral circuit is complex; the second is the use of the recently introduced LinkSwitch series of high-efficiency constant voltage/constant-current three-terminal monolithic switching power supply chip, or the use of LinkSwitch-TN series, the DpA-Switch series of monolithic Switching power supply dedicated IC, which can greatly simplify the circuit, reduce costs, suitable for the composition of medium and small power special switching power supply.
Special integrated switching power supply performance characteristics
(1) The use of high-efficiency constant voltage/constant current monolithic switching power supply LNK500, AC input voltage range of 85 ~ 265V, when the AC input voltage of 265V, leakage current <5μA, rated output voltage of 5.5V, the maximum output current of 0.45A, the output power of 2.5W.
2) Low power consumption, high efficiency, no-load power consumption <0.3W, typical value of power supply efficiency η ≈ 68%.
3) At the peak power point, the output voltage is allowed to have ±10% error when primary.
5)With overheat protection, output short circuit protection and open loop protection.
6)Conforms to the international standard CISpR22B/EN55022B for electromagnetic compatibility.
