What's the difference among AC-DC,DC-DC,Buck,Charger,LDO,PMU ？

AC-DC, DC-DC, Buck, Charger, LDO, PMU are common power circuits that have different working principles, characteristics, and application scenarios, as follows:

1. AC-DC: AC-DC (alternating current direct current) is a power converter that converts alternating current into direct current. It is usually composed of high-frequency transformers, rectifiers, and filters, which can convert alternating current into the required direct current, and has high power conversion efficiency and stability. AC-DC power supply is suitable for fields such as power systems, electronic devices, and household appliances.

There are two types of AD-DC: PSR and SSR are two different power control modes, which have some differences in control methods and characteristics.

a) PSR: PSR (Primary Side Regulation) refers to the use of a main control chip in the main circuit of an AC DC converter to achieve power control. This control method is relatively simple in the control process, using feedback voltage to control the output voltage, and is often applied in cost sensitive power supply applications. Due to the need for sampling and feedback of the current output from the entire power converter during the control process of PSR, its control accuracy is relatively low compared to SSR, making it suitable for more basic power requirements.

b) SSR: SSR (Secondary Side Regulation) refers to the use of a secondary controller to achieve output voltage control during power conversion. The use of chips for feedback and control at the output end usually requires the use of external inductors, capacitors, and other components to process the output voltage and current. Therefore, the SSR control process is more complex than PSR. SSR is more precise and can achieve higher power control accuracy. Power supplies that use SSR have high stability and reliability, and are suitable for applications with high requirements for power control accuracy.

Overall, the cost of PSR power converters is lower, but the control accuracy is relatively low, making them suitable for some basic applications; The SSR power converter has higher control accuracy but higher cost, making it suitable for high-precision power control needs. The final selection should be based on specific application needs and economic conditions.

Main parameters and characteristics:

a) PSR: PSR power control mainly relies on the main control chip, and its conversion efficiency is generally lower than SSR, but its output stability and ability to withstand temperature fluctuations are better.

b) SSR: SSR power control mainly relies on the slave controller, which generally has higher conversion efficiency than PSR, but requires the use of external components at the output end, resulting in relatively high power consumption. SSR has high-precision adjustable output voltage and current, and the output voltage is more stable.

2. DC-DC: DC-DC (Direct Current to Direct Current) converter is a power converter that converts the input DC voltage into another output DC voltage. There are various conversion methods for DC-DC power supplies, such as buck, boost, flyback, etc., which can enable electronic devices to maintain stable output voltage, current, and power within the range of input voltage changes. DC-DC power supply is suitable for electronic devices, LED lighting, solar systems, automotive electronics, and other fields.

3. Buck: Buck is a buck direct current (DC-DC) power converter that reduces the input voltage to the desired voltage level. Buck has high conversion efficiency and stability, making it widely used in devices such as laptops, handheld devices, and mobile power supplies.

4. Charger: Charger, also known as a battery charging device, is a power converter that converts direct current output from an external power source into direct current that matches the battery in the charger. There are various types of chargers, including common ones such as constant voltage chargers and constant current chargers. According to different application scenarios and requirements, different types of charging devices can be selected.

5. LDO: LDO (Low Drop Out) is a low voltage drop linear regulator commonly used to convert high voltage direct current into lower stable direct current. LDO has a low voltage drop and high stability, making it suitable for portable electronic devices such as smartphones, laptops, and digital cameras.

6. PMU: PMU (Power Management Unit) is a chip that integrates power management circuits. PMU has various power processing functions, such as power management, battery charging, power conversion, etc., which can provide efficient power for mobile devices