Preface
Synchronous Rectification Controller is a key control element in a switching power supply system. Its main role is to optimize the rectification process in the power supply system and replace the traditional diode rectifier. By precisely controlling the turn-on and turn-off timing of synchronous rectification MOSFETs, it is designed to reduce power consumption and improve the efficiency of the power supply system.
In traditional switching power supply systems, diode rectifiers are often used to convert alternating current to direct current. However, this method produces a higher on-voltage drop when it is turned on, resulting in increased energy loss. In order to overcome this problem, synchronous rectification technology was introduced, which replaces diodes by controlling MOSFETs, thereby reducing power consumption during turn-on.
The operating principle of the synchronous rectification controller is based on the precise monitoring of the output of the power supply system to ensure that the synchronous rectification MOSFET is turned on at the most appropriate time, minimizing the turn-on voltage drop of the current. This precise control not only improves overall system efficiency, but also helps reduce temperatures and increase power density, making it an indispensable part of high-performance power system design.
This type of controller usually supports a variety of working modes and power topologies, designers can better balance performance, cost and system complexity by selecting the appropriate synchronous rectifier controller, charging head network learned that Huayuan Zhixin has launched HY903, HY913, HY923 for different application scenarios a total of 3 categories of SR synchronous rectifier controller, let's take a look!
Huayuan synchronous rectifier controller
In terms of synchronous rectifier controllers, Huayuan Zhixin has developed three types of SR controllers: HY903, HY913 and HY923 for different application scenarios.
Next, we will conduct an in-depth analysis of these SR synchronous rectification controllers of Huayuan Zhixin, and carefully study their performance characteristics, technical specifications and advantages in different application scenarios. Through a detailed analysis of these controllers, we can better understand their role and effect in the power system.
peculiarity
1. Active pull-down
Huayuan synchronous rectifier controller has the characteristics of active pull-down, which is actively pull-down when powering on to ensure safe operation, which can adapt to the MOS of different manufacturers to reduce customer costs and prevent false triggering.
When the internal resistance is too low, it is necessary to check the pulldown effect, because the Crss is too large and the coupled charge cannot be fully absorbed.
2. Vcc charge pump
Huayuan synchronous rectifier controller is equipped with Vcc charge pump features, in low voltage, Vcc charge pump will increase the voltage and increase the output efficiency (HY903, HY913), the adapter can choose self-powered HY923, which can also work in short circuit.
3. Anti-interference
Huayuan synchronous rectifier controller has a particularly strong anti-interference ability.
Huayuan synchronous rectifier controller has added (Vds-vin) integration function, which will only be turned on when certain conditions are met, and the primary conduction time will not be turned on when the secondary is short, which can resist the interference of narrow pulse or ESD.
Next, the charging head network will conduct an in-depth analysis of the three synchronous rectifier controllers of Huayuan, and carefully study their performance characteristics, technical specifications and advantages in different application scenarios. Through a detailed analysis of these controllers, it is possible to better understand their role and effect in the power system.
HY903
Huayuan HY903 synchronous rectifier controller replaces the traditional Schottky diode with a MOS transistor, drives the MOS transistor by a dedicated controller, and controls its conduction and shutdown according to the on-voltage drop of the body diode of the secondary MOS transistor, which can reduce the voltage drop of the traditional Schottky diode close to 1V to only tens of mV, effectively reducing the loss of the secondary rectification, thereby reducing the loss and temperature rise of the rectifier element.
HY903 synchronous rectification controller supports low-side synchronous rectification, no auxiliary coil required, supports DCM, QR, CCM various flybacks, supports 2.8-25V power supply voltage range, and withstand voltage up to 120V. The high current drive capability is suitable for a variety of synchronous rectifier tubes. The gate drive voltage clamp is 8V, and it has the function of active pull-down at start-up, which is suitable for different manufacturers' MOS.
HY903 supports adaptive pre-shutdown and fast shutdown functions, supports optional minimum shutdown time, integrates charge pump inside the chip, does not use Vds power supply when low-voltage PPS output, greatly improves the low-voltage output efficiency, the lowest output voltage can be as low as 2.8V, due to the existence of the charge pump, the driving voltage is still more than 5V, and has low quiescent current.
Through the dismantling of the charging head network, it was learned that the chip has been adopted by Greenlink 65W 2C1A fast charging charger, LETRON 45W 1A1C dual-port fast charging charger, Meizu mobile phone 30W charger and other products, and has been recognized by the market.
HY913
Huayuan Zhixin HY913 is a digital adaptive multi-mode synchronous rectification controller, which is suitable for DCM/QR/CCM operation mode. The chip has a built-in charge pump, which can boost the supply voltage to ensure that the synchronous rectifier tube is fully conducted, and the efficiency is higher at low voltage output.
HY913 supports the power-on pull-down function, supports the pre-shutdown function, accelerates the shutdown speed, has a 10ns shutdown delay, and supports CCM working mode. When the load is light, the driver will be turned off and the green mode will be entered to reduce the standby power consumption.
HY913 has a built-in integration function, which can prevent the misuse of synchronous rectification, the chip supports a power supply range of 3~25V, which meets the PPS power supply range, the chip has built-in primary and secondary MOSFET conduction protection at the same time, the voltage of the drain detection pin is up to 150V, and it supports internal power supply voltage clamping, no external winding, the peripheral components are simplified, and it has stronger anti-interference ability.
HY923
HY923 is an intelligent digital control synchronous rectifier controller that works as a diode simulator. HY923 can be applied at the positive or negative end, with fast shutdown speed, low reverse spike voltage, withstand voltage of 150V, strong driving ability, driving voltage clamp at 7V, driving pull-down function at start-up, and integrating function to avoid mis-opening of synchronous rectification.
The PD fast charging scheme composed of Huayuan Zhixin HY923, HY1662 and HY5501 was announced, which can realize standby zero power consumption - charging head network
The HY923 can drive standard N-channel power MODIODE FETs to replace Schottky diodes with high efficiency. HY923 adopts digital control technology to optimize DCM/PFM/CCM/QR multi-mode operation in different applications. Robust CCM operation is further enhanced by digital control technology.
The adaptive pre-shutdown scheme not only ensures fast switching, but also minimizes switching losses. The adaptive pre-shutdown scheme optimizes electromagnetic interference (EMI) with a soft SR MOSFET shutdown transition. A voltage-time threshold configurable via the INTG pin avoids false triggering of switching by SR MOSFETs due to parasitic loops in DCM/QR mode.
The HY923 integrates a variety of features to reduce BOM and optimize performance, and is available in a SOT23-6 package.
Summary of the charging head network
The three SR synchronous rectification controller chips launched by Huayuan Zhixin can effectively reduce power consumption and improve the efficiency of the power system by precisely controlling the on-on and off-timing of MOSFETs. These controllers feature features such as active pull-down, Vcc charge pumping, strong immunity to interference, pre-shutdown, and support for multi-mode operation, as well as replacing traditional Schottky diodes to reduce BOM and optimize performance. At present, these three controllers have been widely used in the market and have gained market recognition for improving efficiency and reducing power consumption.