STMicroelectronics L6585DTR

Overview

L6585DTR from STMicroelectronics is a high-voltage BCD-based combo IC integrating PFC controller, half-bridge driver, and ballast control logic for electronic fluorescent lamp ballasts. It delivers transition-mode PFC with ±3% oscillator precision, 1.2µs dead time, programmable pre-heat/ignition timing, and end-of-life protection compliant with lamp-to-ground and block-capacitor-to-ground configurations. Used in commercial lighting systems requiring stable lamp ignition and aging detection.

For engineers reviewing the L6585DTR datasheet, L6585DTR pinout, L6585DTR application, or L6585DTR equivalent, key selection criteria include half-bridge current sensing thresholds (HBCSL = 0.91V typ., HBCSH = 1.6V typ.), PFC gate drive capability (300mA source / 600mA sink), EOL window comparator programmability via EOLP/EOL-R pins, and integrated synchronous bootstrap diode replacement.

Technical Context

The L6585DTR implements dual-loop control: a voltage-mode PFC loop using COMP/INV pins with internal 2.5V reference and THD-optimized multiplier (MULT), and a frequency-modulated half-bridge loop governed by OSC/RF/EOI/TCH timing network. Pre-heat, ignition, and run modes use independent frequency settings (fPRE ≈ 116.7kHz, fRUN ≈ 60.2kHz) controlled by external RC networks.

Its protection architecture includes latched and self-adjusting responses: HBCS pin triggers frequency increase during ignition to limit lamp voltage, while crossing HBCS high threshold in run mode causes latch-off. End-of-life detection uses a programmable window comparator on EOL-R referenced to either fixed or CTR-tracked voltage, blanked during ignition and enabling re-lamp via VSL-DOWN hysteresis (160mV).

Key Specifications

Pinout & Package

Package: SO-20 (Small Outline, 20-pin, 0.600" wide, JEDEC MS-013AC). Pin mapping validated per STMicroelectronics datasheet Rev 5 (May 2007), Figure 3 (top view) and Table 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar electronic ballast controller applications.

Compared with IR2159PBF and L6574DTR, the L6585DTR offers unique integration of TM-PFC, programmable EOL detection, and synchronous bootstrap-reducing BOM count by ≥4 components and enabling adaptive lamp management unattainable with alternatives.

Availability

L6585DTR is available at Aetrix Electronics and suitable for commercial lighting systems, industrial lamp ballasts, medical facility lighting, and public infrastructure lighting requiring stable component supply and long-term design continuity.

Supply support for L6585DTR 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 L6585DTR belongs to ST's high-voltage analog ASSP product line, engineered specifically for energy-efficient electronic ballasts requiring integrated PFC, resonant half-bridge control, and intelligent lamp life management.

FAQ

What is the function of the TCH pin and how is pre-heat time calculated?

The TCH pin controls pre-heat duration via an internal current source (34µA typ.) charging CD until 4.63V, then discharging through RD until 1.50V. Pre-heat time is calculated as T_PRE = (4.63 × C_D / I_CH) + R_D × C_D × ln(4.63/1.52). This RC-based timing ensures repeatable filament heating before ignition, critical for lamp longevity.

How does the L6585DTR implement end-of-life detection and re-lamp functionality?

EOL detection uses a window comparator on EOL-R, programmed via EOLP resistor to set amplitude (220mV or 720mV) and center voltage (fixed or CTR-tracked). During run mode, lamp aging shifts EOL-R voltage outside the window, triggering latch-off. If EOL-R falls below VSL-DOWN (4.63V − 160mV), the IC resets and initiates a new pre-heat/ignition cycle-enabling automatic re-lamp without system reset.

What protection features are latched versus self-adjusting?

Latched protections include PFC over-current (PFCS > 1.75V), half-bridge over-current in run mode (HBCS > 1.6V), and feedback disconnection (CTR < 0.75V). Self-adjusting responses occur during ignition (HBCS > 1.6V increases frequency to limit lamp voltage) and run mode (HBCS > 0.91V increases frequency to limit lamp current), avoiding hard shutdown during transient faults.

Can the L6585DTR drive 600V MOSFETs directly, and what are the gate drive specifications?

Yes-the PFG output delivers 300mA source / 600mA sink peak, while LSD and HSD each provide 290mA source / 480mA sink. All drivers operate with rail-to-rail swing (e.g., HSD high = VBOOT − 0.5V, low = VOUT + 0.3V) and feature 120ns rise/80ns fall times. The integrated synchronous bootstrap diode eliminates external diode requirements for high-side floating supply.