In today’s era of connected technology, smartphones have become an indispensable part of our daily lives. However, as they offer ever more advanced features, power consumption increases have tended to outstrip battery capacity improvements. Requiring some users to charge their phones multiple times per day. Fast chargers emerged as a solution to allow users to fully recharge their devices in a short period. But to ensure chargers do not accelerate battery degradation and shorten the device’s lifespan, high-quality, reliable power supplies are essential. Nexperia’s dedicated AC/DC controller ICs provide lower standby power and system costs, higher conversion efficiency, power density and stronger reliability.
Nexperia is developing a range of AC/DC controller ICs for USB Power Delivery (PD) chargers/adapters and industrial power supplies. The first of these products to be launched include quasi-resonant (NEX806xx) and multi-mode (NEX808xx) flyback controllers along with secondary side synchronous rectifier controllers (NEX8180X). Combining either the NEX806xx or NEX808xx with the NEX818xx and the necessary power discretes forms a complete flyback power solution that is ideal for smartphone PD chargers / adapters and battery chargers for e-bikes / e-tools.
Advanced charging solutions
The primary side controllers (NEX806xx and NEX808xx) adopt valley detection technology to reduce switching losses and achieve high conversion efficiency in the full voltage range. Pulse Frequency Modulation (PFM) cuts the standby power consumption of the system, and with a sampling level of 400 mV further reduces system power consumption. Helping simplify system design, the VCC from 10 to 83 V to support a wide PD voltage output without the need of additional LDO circuits.
Nexperia’s NEX806xx and NEX808xx also have a peak power mode, capable of doubling the output power for tens of milliseconds to manage short-term sudden load increases. In addition, they incorporate complete protection functions, including brown in/out of line voltage, VCC overvoltage/undervoltage protection, output short circuit protection, output over voltage protection, overload protection, internal and external over temperature protection. Spread spectrum technology also has better EMI performance.
The secondary side controller employs innovative adaptive control to reduce the risk of misoperation of the secondary synchronous rectifier MOSFET while ensuring reliable operation under light load conditions, as illustrated in Figure 1. This controller also features adjustable turn-on blanking time which helps to prevent premature controller shutdowns caused by high parasitic inductance, such as when using DIP package MOSFETs or PCBs with significant inductance. This ensures the system remains highly reliable.
Innovative packaging and superior thermal performance
All of these AC/DC controller ICs utilize TSOT23-6 packaging, which features a standard pin layout for easy replacement and shortening the design cycle for new projects. Importantly, they also incorporate innovative flip-chip copper pillar packaging, which offers significantly lower thermal resistance compared to traditional wire-bonding methods.
A typical 65 W PD demo system with a power density of 1.9 W/cm3 (31.9 W/in3) is shown in Figure 2. In this case it uses the NEX80605 quasi resonant flyback controller and NEX81802 high-frequency synchronous rectifier controller. The full load efficiency under 230 VAC and 20 V @ 3.25 A reaches 93.8%. Meanwhile, benefiting from the innovative flip-chip packaging, the ICs have a very low junction temperature.
To demonstrate the thermal performance of the ICs in practical applications, the demo was placed in a chamber and the ambient temperature was gradually increased until OTP occurred inside the IC. The measured ambient temperature was 113 °C. Compared with traditional wire bonding packaging, these products can therefore withstand ambient temperatures around 24 °C higher (see Figure 3). This excellent heat dissipation makes the new type of packaging ideal for designing high-power-density consumer and industrial flyback power supplies.
Typical industrial auxiliary power supply
Of course, while Nexperia’s AC/DC controllers are ideal for PD chargers / adapters, they are a match for industrial auxiliary power supplies (12 / 24 V DC) that demand high reliability (Figure 4). Incorporating additional safety and protection technologies like brown-in/out, valley conduction, spread spectrum, and peak load mode, they meet industry standards and ensures comprehensive reliability and certification testing.
Product portfolio
Nexperia's new power ICs address the needs of fast-charging adapters and other power supplies, offering reliable, efficient and easy-to-design solutions. The initial range of primary and secondary side controllers are now in mass production. On the primary side there is a choice of four quasi-resonant controllers (NEX80601, NEX80602, NEX80605 and NEX80611) with maximum frequencies between 130-170 kHz and five multi-mode controllers (NEX80801, NEX80805, NEX80806, NEX80808 and NEX80809) with maximum frequencies between 65-85 kHz. When it comes to the secondary side there are two adaptive Synchronous Rectifier (SR) controllers (NEX81801 and NEX81802) with adjustable turn-on blanking times of 1.0-2.0 us and 0.5-1.5 μs respectively.
For more information, please visit our AC/DC controller ICs product page.
