U3018

U3018(D) is a high-performance, low-cost PWM control power switch designed for off-line low-power buck applications. It features a simple peripheral circuit with a minimal component count. The built-in high-voltage startup MOSFET helps improve the system's surge withstand capability. Unlike conventional PWM power switches, the U3018(D) has no fixed internal clock to drive the MOSFET; instead, the switching frequency automatically adjusts in response to load variations. The IC employs multi-mode PWM control technology, which effectively simplifies peripheral circuit design, improves line and load regulation, and eliminates audible noise during system operation. In addition, the internal peak current detection threshold is automatically adjusted based on actual load conditions, helping to reduce standby power consumption at no load. The U3018(D) integrates comprehensive self-recoverable protection features, including VDD undervoltage protection, cycle-by-cycle current limiting, output overvoltage protection, overtemperature protection, overload protection, and VDD overvoltage protection.

Applications

• Telecom 90V power systems
• Ethernet PoE
• Industrial control
• Inverter systems

Key features

• Input voltage range: 18V ~ 180V (output 14.3V)
• Integrated 2.5A 180V MOSFET
• Integrated 200V high-voltage startup circuit
• Multi-mode control for noise-free operation
• Supports buck and buck-boost topologies
• Default output 14.3V
• Standby power consumption below 50mW
• Excellent line regulation and load regulation
• Integrated soft-start circuit
• Internal protection features: overload protection, cycle-by-cycle current limiting, output OVP, VDD OVP, UVLO, and voltage clamp protection