The NCP1680 PFC Controller from ON Semiconductor - classic power design for reliable efficiency

NCP1680 PFC Controller from ON Semiconductor is a digital-ready, high-efficiency power factor correction chip used in modern AC-DC power supplies. The product is driving shares of ON Semiconductor (NASDAQ: ON, ISIN US6821891035).

By Elena Vance, ad hoc news Classics & Longsellers Desk. Reviewed July 05, 2026, 1:25 AM ET. Details in the imprint.

NCP1680 PFC Controller from ON Semiconductor sits on the corner of a lab power board, a small matte-black IC surrounded by humming coils and warm heatsinks. You notice the faint smell of flux and the steady glow of an LED as an engineer dials up the load.

What the NCP1680 actually does

At its core, the NCP1680 is an integrated power factor correction (PFC) controller designed for AC-DC power supplies, typically ranging from about 100 W to well above 1 kW in server, PC, and industrial gear.

Power factor correction helps align the current waveform with the voltage waveform so connected equipment draws power more cleanly from the grid, reducing wasted reactive power and meeting utility and regulatory requirements.

Why US engineers still spec this classic

For US-based design teams building ATX power supplies, gaming PSUs, telecom rectifiers, or industrial drives, controllers like NCP1680 remain a staple choice. They sit upstream in the power train, between the rectified AC input and the main DC-DC conversion stages.

Because the NCP1680 implements critical-conduction or transition-mode PFC, it can deliver high efficiency with relatively simple magnetics and switching elements, which matters when you’re squeezing 80 PLUS Gold or better efficiency ratings out of a consumer power supply.

Inside the feature set

The NCP1680 belongs to ON Semiconductor’s family of transition-mode PFC controllers that integrate the necessary comparators, reference circuitry, and drive logic into a single chip.

It typically supports functions such as over-voltage protection, under-voltage lockout, over-current protection, and soft-start, which together help protect both the power supply and connected equipment from line transients or startup surges.

Efficiency and regulatory context

US and international efficiency standards for power supplies have tightened steadily, from voluntary 80 PLUS ratings to mandated efficiency requirements in categories like external adapters and computer power supplies.

Power factor requirements also matter for data center operators and industrial users because poor power factor can trigger penalties from utilities and reduce the effective capacity of infrastructure like transformers and cabling.

From the lab bench to the rack

When you watch a test engineer like Michael Torres at a contract design house in Texas bring up a new server PSU, the NCP1680’s role becomes tangible. He clips a current probe around the input lead and points to the oscilloscope.

The current trace snaps into a tighter, more sinusoidal shape compared to a non-PFC design, and the real-time power factor readout climbs closer to 0.99. For operators paying commercial electricity rates, that shift shows up directly on their utility bills.

Design considerations for US OEMs

For US-based OEMs shipping power supplies into enterprise or industrial markets, component availability and long-term support are critical. ON Semiconductor promotes extended availability for its industrial-grade parts, though exact lifecycles can vary by product family.

The NCP1680 is distributed through major US component distributors, and designers can source it in tape-and-reel format for automated assembly or in smaller quantities for prototyping.

Digital control and monitoring trends

While NCP1680 itself is an analog controller, newer designs often pair analog PFC control with digital monitoring via microcontrollers or PMBus-enabled supervisors. This allows data center operators to collect telemetry on input voltage, current, and power factor.

Such hybrid designs can combine NCP1680-style analog efficiency with digital configurability and remote monitoring, a combination increasingly favored in high-density racks where per-watt efficiency and remote troubleshooting matter.

Position in ON Semiconductor’s portfolio

ON Semiconductor, based in Scottsdale, Arizona, positions itself as a power and sensing company with a broad portfolio of discrete power devices, controllers, and analog ICs.

Its PFC controllers sit alongside MOSFETs, IGBTs, gate drivers, and rectifiers, giving OEMs a one-stop portfolio for most stages of a power conversion chain from AC input through regulated DC rails.

What this means for investors

For US retail investors looking at ON Semiconductor stock, legacy products like the NCP1680 may not dominate headlines but they contribute to the steady, design-win-driven base of the company’s revenue.

Shares of ON Semiconductor (NASDAQ: ON) trade in US dollars and reflect a mix of mature product lines and newer bets on automotive and industrial power, with PFC controllers helping underpin the company’s reputation in efficient power conversion.

Key facts about NCP1680 PFC Controller

• Product: NCP1680 PFC Controller
• Manufacturer: ON Semiconductor Corp.
• Category: Classics & Longsellers power management IC
• Launch: Introduced as part of ON Semiconductor’s transition-mode PFC controller line, in market for several years
• MSRP / Price: Typically under 2 USD per unit in high-volume orders via distributors; small-quantity pricing may be higher
• Availability: Widely available through US distributors and global channels for industrial and consumer PSU designs
• Target audience: Power supply designers, data center and industrial OEMs, PC and gaming PSU manufacturers
• Standout / USP: Mature, transition-mode PFC controller enabling high efficiency and robust protection for AC-DC power supplies

This article was AI-assisted and editorially reviewed. Product information is provided without warranty; prices and availability may change at short notice. Not investment advice and not a buy or sell recommendation. Securities trading carries risks up to total loss.