U3210

U3210 is a high-performance, low-cost PWM control power switch designed for offline low-power buck applications, featuring a simple peripheral circuit with a minimal component count. The device integrates a high-voltage MOSFET (650V) startup module to enhance system surge immunity. Unlike conventional PWM power switches, U3210 has no fixed internal clock to drive the MOSFET; instead, the switching frequency automatically adjusts in response to load variations. The chip employs multi-mode PWM control technology, which effectively simplifies peripheral circuit design, improves line and load regulation, and eliminates audible noise during operation. In addition, the internal peak current detection threshold automatically adjusts based on actual load conditions, significantly reducing standby power consumption at no load. U3210 integrates comprehensive protection features with auto-recovery capability, including VDD undervoltage protection, cycle-by-cycle current limiting, output overvoltage protection, overtemperature protection, overload protection, and VDD overvoltage protection.

Applications

• Small appliance power supplies
• Industrial control

Key features

• Integrated 650V high-voltage startup circuit
• Multi-mode control, noiseless operation
• Supports buck and buck-boost topologies
• Default 12V output (FB pin floating)
• Standby power consumption below 50 mW
• Excellent line and load regulation
• Integrated soft-start circuit
• Built-in protection features: overload protection, cycle-by-cycle current limiting, output OVP, VDD overvoltage, undervoltage, and voltage clamp protection