Design Scheme and Characteristics of Special Integrated Power Supply
Compared with traditional switching power supplies, special integrated switching power supplies have the characteristics of novel circuits, unique functions, advanced performance, and a wide range of applications. Common special integrated switching power supplies are usually designed using a single chip switching power supply integrated circuit, coupled with corresponding peripheral circuits (including control loops), which have different output characteristics and application fields, and can meet the needs of different users.
The special integrated switching power supply mainly includes the following 5 types:
1) Composite switching power supply;
2) Constant voltage/constant current (CV/CC) switching power supply;
3) Cut off output type switching power supply;
4) Constant power output switching power supply;
5) Other specialized switching power supplies, such as High Speed Modem power supply, DVD power supply, etc.
Design Scheme and Characteristics of Special Integrated Switching Power Supply
There are two design schemes for special single chip switching power supplies: the first is to use a universal single chip switching power supply integrated circuit (such as TOPSwitch II, TOPSwitch FX, TOPSwitch GX series, etc.), combined with peripheral circuits such as voltage control loop and current control loop, which are characterized by high output power but complex peripheral circuits; The second method is to use the recently released LinkSwitch series high-efficiency constant voltage/constant current three terminal single chip switching power supply chips, or to choose LinkSwitch TN series and DpA Switch series single chip switching power supply dedicated ICs. This can greatly simplify the circuit, reduce costs, and be suitable for constructing special switching power supplies with medium and small power.
Performance characteristics of special integrated switching power supply
1) Adopting high-efficiency constant voltage/constant current single chip switching power supply LNK500, with an AC input voltage range of 85-265V. When the AC input voltage is 265V, the leakage current is<5 μ A. The rated output voltage is 5.5V, the maximum output current is 0.45A, and the output power is 2.5W.
2) Low power consumption, high efficiency, no-load power consumption<0.3W, typical value of power efficiency η≈ 68%.
3) At the peak power point, an error of ± 10% is allowed in the output voltage when the primary voltage is used.
5) Equipped with overheat protection, output short circuit protection, and open loop protection functions.
6) Comply with international standards for electromagnetic compatibility CISpR22B/EN55022B.
