STMicroelectronics L6564HTR

Overview

L6564HTR from STMicroelectronics is a high-voltage startup transition-mode (TM) power factor correction (PFC) controller IC designed for the master-stage PFC pre-regulator in AC-DC systems. It integrates a 700 V startup source, bi-directional 1/V² voltage feedforward, ±1% internal reference (at T_J = 25 °C), 600 mA source / 800 mA sink totem-pole gate driver, and comprehensive protection including OVP, brownout detection, and inductor saturation sensing. It targets >400 W IEC61000-3-2/ JEITA-MITI compliant SMPS for LED luminaires and high-end adapters.

For engineers reviewing the L6564HTR datasheet, L6564HTR pinout, L6564HTR application, or L6564HTR equivalent, key selection criteria include its 700 V HVS pin rating, 100 µA max startup current, 6 mA max operating bias current, -40 to 150 °C junction temperature range, and SO-14 package compatibility with high-voltage isolation requirements in offline PFC designs.

Technical Context

The L6564HTR implements current-mode control in transition mode using zero-current detection (ZCD) on pin 11 to trigger MOSFET turn-on, synchronized with boost inductor demagnetization. Its proprietary 1/V² feedforward circuit-fed via MULT (pin 3) and VFF (pin 5)-linearizes gain across universal input (85–265 V_AC) and improves line transient response during both surges and sags.

Protection architecture includes latched shutdown on feedback loop disconnection (detected when INV < 1.66 V while PFC_OK > 2.5 V), active inductor saturation detection (CS pin threshold at 1.7 V), and dual-threshold PFC_OK monitoring (2.5 V OVP trip, 0.27 V enable) enabling remote on/off control and DC-DC coordination.

Key Specifications

Pinout & Package

Package: SO-14 (Small Outline, 14-pin, surface-mount), with creepage/clearance optimized for 700 V high-voltage isolation; pin 8 (HVS) and pins 7/9/10 (N.C.) provide reinforced safety spacing per IEC61000-3-2 requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE3PCS01G and UCC28056, the L6564HTR delivers superior universal-input THD performance via its proprietary 1/V² feedforward, eliminates startup resistor losses with 700 V HVS, and provides hardware-latched protection critical for medical and industrial reliability-making it optimal for >400 W, standards-compliant PFC stages.

Availability

L6564HTR is available at Aetrix Electronics and suitable for LED street lighting drivers, industrial AC-DC adapters, and medical-grade power supplies requiring stable component supply, long-term lifecycle support, and compliance with EN61000-3-2 and JEITA-MITI standards.

Supply support for L6564HTR 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, specializing in power management, analog, microcontrollers, and automotive ICs-with over 40 years of high-reliability analog design heritage.

The L6564HTR belongs to ST's legacy PFC controller product line, engineered specifically for high-efficiency, standards-compliant offline AC-DC conversion in industrial, lighting, and computing power supplies.

FAQ

What is the purpose of the HVS pin (pin 8) and how is it used in circuit design?

The HVS pin is a 700 V-rated high-voltage startup source that connects directly to the rectified mains input. Internally, it provides a current-limited charge path to the VCC capacitor, eliminating the need for an external high-voltage startup resistor. During normal operation, it disables automatically once VCC reaches 12 V; during faults like output short-circuit, it re-enables only when VCC drops to the UVLO threshold (~9.5 V), minimizing power loss and thermal stress.

How does the bi-directional 1/V² feedforward improve line transient response?

The L6564HTR's feedforward uses separate MULT (pin 3) and VFF (pin 5) inputs to derive both instantaneous and RMS line voltage information. This enables real-time gain adjustment that compensates equally for line sags and surges-reducing output voltage deviation to <±2% during 10%–90% step changes in input voltage, and cutting recovery time to under 10 ms compared to conventional PFC controllers.

Can the L6564HTR be used in continuous conduction mode (CCM) PFC applications?

No-the L6564HTR is strictly a transition-mode (TM) controller, relying on zero-current detection (ZCD) at pin 11 to trigger MOSFET turn-on. It lacks the internal ramp generator, average-current sensing, or CCM-specific compensation features required for stable CCM operation. For CCM designs, ST recommends the L4984D or ICE3PCS01G families instead.

What protection mechanisms prevent damage during boost inductor saturation?

When the CS pin voltage exceeds 1.7 V-indicating abnormal peak current due to core saturation-the L6564HTR immediately halts switching, holds the GD output low, and initiates a controlled restart after a fixed delay. This prevents MOSFET avalanche breakdown and limits stress on the boost diode and output capacitor, verified in ST's EVL6564H demo board testing under worst-case saturation conditions.