NCP1612BDR2G

Overview

The NCP1612BDR2G is an active power factor correction (PFC) controller from onsemi, designed for offline applications. It utilizes a Current Controlled Frequency Foldback (CCFF) method to drive the PFC boost stage, optimizing efficiency across load ranges. The device operates in Critical Conduction Mode (CrM) and supports low standby losses. It features a wide VCC range suitable for high-impedance startup resistors and includes robust protection mechanisms such as fast output overvoltage protection and bulk under-voltage detection.

Feature Summary

• Implements Current Controlled Frequency Foldback (CCFF) mode to maximize efficiency at nominal and light loads by reducing frequency as current decreases.
• Enables near-unity power factor operation even during frequency foldback conditions.
• Supports skip mode optimization to minimize standby losses during low current periods near line zero-crossing.
• Features low startup current and wide VCC operating range, allowing pre-charging via high-impedance resistors.

Applications

• AC-DC adapters
• Flat panel televisions
• Lighting ballasts

Procurement Notes

Verify the specific suffix 'B' against the manufacturer's official datasheet to confirm pinout compatibility and electrical characteristics relative to other variants like 'A'. Ensure the SOIC-8 package dimensions match the target PCB footprint. Confirm RoHS compliance status through the latest component certification documents provided by onsemi before finalizing procurement.

Selection Notes

Select this component for medium-power offline applications requiring high efficiency and low standby power consumption. The CCFF architecture makes it suitable where minimizing light-load losses is critical. Consider the wide VCC range if designing for systems with limited startup current capabilities or high impedance bias networks. Evaluate thermal performance within the SOIC-8 package for the intended power density.

Part Context

This part belongs to the NCP1612 series of PFC controllers. The series includes variants such as NCP1612A, NCP1612A1, NCP1612A2, NCP1612A3, and NCP1612B2. These devices share the core CCFF control methodology but may differ in startup voltage thresholds, VCC ranges, and specific protection feature configurations. The B variant is optimized for specific startup and operating voltage requirements compared to the A series.

Replacement Considerations

Direct substitutes include other NCP1612 variants such as NCP1612B2 or NCP1612A2, depending on whether the application requires the specific startup characteristics of the B version or the lower start-up level of the A version. Verify that any replacement maintains the SOIC-8 package and compatible control logic for the existing boost converter design.

FAQ

How does the NCP1612 achieve low standby losses?

It uses a Current Controlled Frequency Foldback (CCFF) method that linearly reduces the switching frequency as the inductor current decreases, reaching approximately 20 kHz at null current, thereby minimizing losses at light loads.

What is the purpose of the skip mode in this controller?

Skip mode optimizes efficiency further by skipping cycles when the current is very low near the line zero-crossing, preventing inefficient power transmission during these periods.

Can the skip mode be disabled?

Yes, the skip mode can be disabled by applying a 0.75 V offset to the FFcontrol pin if higher power factor quality is required at the expense of some efficiency.