E-L4981AD

Overview

The L4981AD is a Power Factor Correction (PFC) controller from the L4981A series, manufactured by STMicroelectronics. It operates in Surface Mount Technology (SMT) using an SO-20 package with 20 pins. The device functions at a switching frequency of 115 kHz and supports a maximum supply voltage of 19V. It is designed for high-efficiency power supplies with universal mains input voltages ranging from 85V to 265V AC. The operational temperature range spans from -40°C to +125°C.

Feature Summary

• Fixed frequency average current mode PWM control for minimum noise sensitivity
• Integrated overvoltage and overcurrent protection mechanisms
• Low start-up current consumption typical of 0.3mA
• Precise 2% on-chip reference voltage available externally

Applications

• High efficiency-mode power supplies
• AC to DC conversion systems with universal mains input
• Bridgeless power factor correction controllers
• Server and telecom infrastructure power units

Procurement Notes

Verify the specific suffix (e.g., TR for tape/reel or AD for tube) against your assembly requirements. Confirm the exact operating frequency specification, as sources indicate both 100 kHz and 115 kHz variants within the L4981 family. Ensure compatibility with BCD 60II technology constraints if integrating into existing designs.

Selection Notes

Select this component when fixed frequency operation is required rather than line-modulated frequency found in the L4981B variant. It is suitable for applications requiring average current mode control without slope compensation. Consider the SO-20 package dimensions and thermal characteristics for PCB layout planning.

Part Context

The L4981AD belongs to the L4981A series, which utilizes fixed frequency average current mode control. This distinguishes it from the L4981B series that employs line-modulated frequency. The device is part of STMicroelectronics' portfolio for high-power PFC pre-regulators, implemented in BCD 60II technology to achieve high power factors up to 0.99.

Replacement Considerations

L4981B serves as a functional alternative if line-modulated frequency operation is preferred for input filter optimization. L4983 and L4984D are contemporary CCM PFC controllers but differ in control architecture and feature sets.