U3213D

U3213D is a high-performance, low-cost PWM-controlled power device designed for off-line low-power buck applications, featuring a simple peripheral circuit with a minimal component count. The built-in high-voltage MOSFET enhances the system's surge withstand capability. Unlike conventional PWM controllers, U3213D has no fixed internal clock to drive the MOSFET, allowing the switching frequency to adjust automatically with load variations. The chip also 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 to actual load conditions, significantly reducing standby power consumption under no-load conditions. U3213D integrates comprehensive auto-recovery protection features, including VDD undervoltage protection, cycle-by-cycle current limiting, output overvoltage protection, over-temperature protection, overload protection, and VDD overvoltage protection.

Applications

• Small appliance power supplies
• Industrial control

Key features

• Integrated 3A 150V MOS
• Integrated 200V high-voltage startup circuit
• Integrated current-limiting resistor (default 1.2A)
• Operating range: VIN-VOUT > 3V, Ipk < 2A
• Default 15V output (FB pin floating)
• Low power consumption mode operation
• Supports buck and buck-boost topologies
• Standby power consumption < 50mW
• Excellent line regulation and load regulation
• Integrated soft-start circuit
• Internal protection features: Overload Protection (OLP), cycle-by-cycle current limiting (OCP), output overvoltage protection (OVP), VDD overvoltage, undervoltage, and voltage clamp protection