STMicroelectronics L6562N

Overview

L6562N from STMicroelectronics is a transition-mode (TM) power factor correction (PFC) controller IC in DIP-8 package, featuring 1% internal reference voltage (2.5 V), ≤70 µA start-up current, and -600/+800 mA totem-pole gate driver. It implements proprietary THD-optimized multiplier architecture for IEC61000-3-2 compliance in 300W SMPS designs used in desktop PCs and monitors.

For engineers reviewing the L6562N datasheet, L6562N pinout, L6562N application, or L6562N equivalent, key selection criteria include its ultra-low quiescent current (≤4 mA), extended VCC range (10.3–22 V), precise output overvoltage protection (±12% threshold tolerance), and zero-current detection with 1.6 V negative-edge trigger for reliable TM operation.

Technical Context

The L6562N operates in transition mode using zero-current detection on pin 5 (ZCD) to initiate MOSFET turn-on at inductor demagnetization, minimizing switching losses. Its highly linear multiplier (pin 3) accepts rectified mains voltage and interfaces with the error amplifier output (pin 2) to generate a sinusoidal current reference.

Internal circuitry includes a two-step overvoltage protection (OVP): dynamic OVP triggers at 40 µA COMP current (≈40 V output excursion), while static OVP activates during low-load saturation of the error amplifier. The 2.5 V internal reference (1% accuracy at Tj = 25 °C) sets the regulated output voltage via external resistor divider on pin 1 (INV).

Key Specifications

Pinout & Package

DIP-8 package per ECOPACK® 1.1 standard, 0.3" width, 2.54 mm pitch, lead-free second-level interconnect. Thermal resistance R_{th j-amb} = 100 °C/W (SO-8) / 150 °C/W (DIP-8).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transition-mode PFC controller applications.

Compared with L6562D, the L6562N offers superior thermal dissipation in through-hole prototyping and repair scenarios; versus UCC3817DW, it delivers lower THD and simpler magnetics design but lacks CCM flexibility for high-power (>500W) systems.

Availability

L6562N is available at Aetrix Electronics and suitable for desktop PC power supplies, IEC61000-3-2 compliant monitor PSUs, and hi-end AC-DC chargers requiring stable component supply across industrial temperature ranges (-40 to +150 °C).

Supply support for L6562N includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The L6562N belongs to ST's legacy PFC controller product line, engineered specifically for cost-effective, high-efficiency transition-mode boost pre-regulators targeting sub-300W IEC61000-3-2 applications.

FAQ

What is the purpose of the ZCD pin on the L6562N?

Pin 5 (ZCD) senses the boost inductor's demagnetization via a resistor divider from the switch node. A negative-going edge below 1.6 V triggers MOSFET turn-on, ensuring zero-current switching for high efficiency and low EMI in transition-mode operation. It also serves as the disable input when pulled above 250 mV.

How does the L6562N achieve low THD in AC input current?

The L6562N uses a proprietary multiplier circuit that adds a controlled positive offset to the current reference near AC line zero-crossings. This forces earlier MOSFET conduction to discharge the bridge rectifier's high-frequency capacitor, eliminating conduction dead-angle and reducing THD to under 4% at 85 VAC full load.

Can the L6562N be used in continuous conduction mode (CCM)?

No - the L6562N is exclusively designed for transition-mode (critical conduction mode) operation. It lacks the slope compensation, fixed-frequency oscillator, and high-bandwidth current loop required for stable CCM. Attempting CCM operation results in subharmonic oscillation and loss of power factor correction.

What is the maximum recommended output power for an L6562N-based PFC stage?

ST specifies the L6562N for PFC pre-regulators up to 300W, validated in reference designs like EVAL6562-80W (80W) and 250W wide-range schematics. Above 300W, thermal stress on the DIP-8 package and gate drive limitations increase risk of instability and reduced reliability.