High efficiency power conversion circuit AP2406L

Wuxi Xinpeng Microelectronics Co., Ltd. has launched the high-efficiency power conversion circuit AP2406L for battery-powered portable electronic products. According to the characteristics of backlight LEDs, Xinpeng Microelectronics has developed a series of constant current drive circuits that can meet the driving requirements of white light LEDs in different systems. In addition, Xinpeng Microelectronics has independently developed advanced high-low voltage compatible processes in a combination of industry, academia and research, relying on the mature domestic wafer processing production line, and successfully launched the high-efficiency green single-chip switching power supply AP8022 product based on this process, which can meet AC-DC conversion applications within 20W and has been widely used in the adapter market and low-power home appliance market.

1. High-efficiency DC/DC power converter AP2406L:

The high-efficiency power conversion circuit AP2406L adopts current-mode synchronous rectification technology, which can efficiently convert high voltage into the required low voltage. The maximum output current can reach more than 700mA, and only consumes 40uA current when no-load, with a maximum efficiency of 96%.

The circuit uses two switching modes that can be switched adaptively according to the load size: PWM and PFM. When the load becomes smaller, it can automatically switch from PWM mode to PFM mode, which greatly improves the working efficiency at low load. It is especially suitable for the sleep or standby working mode of the system main chip. At this time, its power conversion efficiency remains above 80%, ensuring the long-term standby needs of the system. In addition, the input withstand voltage of up to 7.0V can easily meet the application of four dry batteries and the needs of USB hot plugging, and has better adaptability than the same type of conversion circuit. In PWM working mode, its output ripple can reach less than 10mV. If the PCB layout and peripheral components are properly selected, the ripple can be as low as less than 5mV. It adopts a miniature SOT23-5 or SOT89-5 package, which is compatible with a variety of pin arrangements.

ChipPon Microelectronics has also launched similar series of products, including AP2404, AP2404L, AP2406, AP2506, AP2506L, AP2408, AP2410 and AP2802, to meet the different requirements of different systems for load current and working mode. This series is now widely used in MP3, MP4, GPS, DSC, LCD-TV and other products.

2. High-efficiency green single-chip AC/DC switching power supply AP8022

The single-chip switching power supply AP8022 product can meet the AC/DC conversion application within 20W, and has been widely used in the adapter market and low-power home appliance market. The circuit adopts the current control mode, integrates a 700V high-voltage MOSFET on the chip, and has a built-in oscillator switching frequency of 50KHz~60KHz. It has a complete protection scheme for overvoltage, undervoltage, overcurrent, short circuit, overtemperature, etc.; and has an automatic restart function. The power consumption of the chip is less than 0.1W when it is unloaded. The packaging form is mainly DIP8, and there are other forms. Compared with the solution of separating the PWM control chip and the power tube, it can reduce the number of peripheral components and the area of ​​PCB, especially without the need to use high-voltage startup resistors, which not only effectively reduces the standby power consumption, but also improves the safety performance of the system; the VDD input voltage range of the chip reaches 30V, so there is no need to use special clamping measures to limit the change of VDD. This circuit has been adopted by customers in large quantities.

3. High efficiency white light LED driver series circuit

The AP3127 circuit in series mode adopts an inductive boost mode, with a switching frequency of up to 1.0MHz and a feedback control voltage as low as 0.25V, which provides a guarantee of high efficiency. The maximum voltage can be increased to 17.5V, and up to 4~5 white light LEDs can be connected in series. Up to 12 white light LEDs can be used in series (4 parallel and 3 series). The enable end of the circuit can accept PWM signals to achieve uniform brightness adjustment. It adopts SOT23-6 package and has an overvoltage protection pin. It is suitable for lithium battery-powered products and has been widely used in MP3/4, PMP, and mobile phones.

The voltage-doubling parallel AP3300 circuit can drive up to 5 parallel LEDs. Depending on the battery voltage and the forward voltage drop of the LED, the output voltage range can be adaptively adjusted to 1 or 1.5 times the input voltage to maintain a high driving efficiency; the built-in current matching circuit ensures that the error of each current is within 0.5%. The drive current can be set by an external resistor, and the brightness of the lamp can be adjusted by adding a PWM signal to the enable end. The frequency of the internal charge pump is as high as 1MHz, and the required peripheral components are only four micro capacitors. It uses a 3mmx3mm DFN16 package, which saves PCB space. In addition, a variety of different pin arrangements are available to facilitate customer selection.

The linear parallel AP3600/1 current sharing circuit can provide 3 or 4 current sharing control, with a constant current of 20mA for each channel. The voltage at the current sharing pin can be as low as 60mV. When the power supply voltage is slightly higher than the forward voltage drop of the LED, the power supply efficiency is greatly improved. The brightness of the LED can be controlled by PWM signal. The package form is SOT23-6. This circuit has no oscillation, which completely eliminates the EMI problem that may be caused by other types of circuits. As the forward voltage drop of white light LEDs decreases, this series of circuits will be more widely used in portable electronic products.