Application of synchronous COT buck converter GX2202 in xDSL modems

XDSL (Digital User Line) modems are broadband access devices widely used in home and enterprise networks, mainly converting digital signals and analog signals to achieve high-speed data transmission. However, its complex internal circuit system requires strict stability and efficiency of the power supply. The synchronous buck converter, as a key power management component, is responsible for accurately reducing the input voltage and providing stable power supply for each module.

Synchronous buck converter is an important branch of power supply, generally divided into Buck, Boost, etc., widely used in the DC power supply part of product power supply, supplying power to different functional modules. According to isolation classification, non isolated DC-DC and isolated DC-DC are mainly used in fields such as power instruments, network communication, security, home appliances, industrial control, new energy, and automobiles.

XDSL modems typically contain multiple core modules, each with significantly different power requirements. GX2202 is an efficient synchronous buck converter that can improve modem performance and reduce power consumption. The chip‘s output current can reach up to 2A, with specific functions such as input undervoltage protection, overheating protection, and output short circuit protection.

The GX2202 adopts an adaptive COT control scheme, which can achieve very fast transient response and provide a very smooth transition when the output changes from heavy load to light load. During light load periods, it will enter PFM mode to save switch losses and achieve high efficiency. COT control can maintain a constant switching frequency when the input voltage and output load change.

Main features of synchronous buck converter GX2202:

4.5V to 18V wide input working range

19V input overvoltage protection

Maximum output current: 2A; efficiency: 92%

• No load static current: 100uA, feedback reference voltage: 600mV ± 2%

Fixed switching frequency: 800kHz

Adaptive COT control

Efficient PFM mode under light load

Hiccup mode overcurrent protection and short circuit protection

• Periodic peak and valley current limits

1ms internal soft start, thermal shutdown, and UVLO