NCP1611ADR2G

The NCP1611ADR2G is an advanced Power Factor Controller IC designed by ON Semiconductor for high-efficiency PFC boost stages. It employs an innovative Current Controlled Frequency Fold-back (CCFF) method, allowing it to operate classically in Critical Conduction Mode (CrM) at higher currents and linearly decay frequency down to 20 kHz at lower currents. This CCFF mode maximizes efficiency at both nominal and light loads, significantly reducing standby losses.

Key features include near-unity power factor, on-time modulation for proper current shaping, skip mode near line zero crossing, and a dynamic response enhancer for fast line/load transient compensation. The device supports valley turn-on and offers high drive capability (-500 mA / +800 mA). It operates within a VCC range of 9.5 V to 35 V and has low start-up consumption. The NCP1611ADR2G is compliant with EN61000-3-2 Class C across a wide load range, making it suitable for dimmable light ballasts.

This IC is housed in a compact 8-SOIC (0.154", 3.90mm Width) surface mount package. It incorporates several safety features, including non-latching over-voltage protection, brown-out detection, over-current limitation, thermal shutdown, and open ground pin fault monitoring. The specific start-up voltage depends on the version: the A version has a low VCC start-up level of 10.5 V, while the B version requires a higher 17.0 V start-up level. This controller is ideal for applications such as PC, TV, and adapter power supplies, LED drivers, and light ballasts requiring power factor correction.