Microchip HV9805

Description

The HV9805 driver integrated circuit (IC) is targeted at general LED lighting products, such as LED lamps and LED lighting fixtures with a maximum power rating of about 25W at 120VAC and 50W at 230VAC. A two-stage topology provides true constant current drive for the LED load while drawing mains power with high power factor. The first stage, a boundary conduction mode boost converter, transfers power from the AC line to a second stage linear current regulator with high power factor and high efficiency. The linear current regulator, arranged for operation with low overhead voltage, transfers power from the first stage to the LED load with true constant current (no ripple) and protectsthe LED load from the overvoltage that may pass from mains to the output of the first stage. The IC is particularly geared to drive a high voltage LED load. An LED load arranged as a high-voltage load is capable of offering cost advantages in terms of heat management and optics. The boost converter employs a cascode switch for high-speed switching and convenient generation of the VDD supply. The control device of the cascode switch is an integral part of the HV9805 and is rated at 700 mA peak. Current for powering the VDD supply is derived by means of an internal connection to the cascode switch.

Features

• 1st Stage with:
• Boundary Conduction Mode (BCM) boost with power factor correction
• High power factor (0.98 typical)
• High efficiency (90% typical)
• Simple VDD supply: no auxiliary winding required
• Boost converter cascode switch: internal switch rated at 700 mA peak
• Supports up to 25W at 120VAC
• Supports up to 50W at 230VAC
• 2nd Stage:
• Linear post-regulator with low overhead voltage
• Zero LED current and brightness ripple
• Provides true DC light and protects load from line voltage transients
• Output load open circuit protection
• High efficiency
• ±4% reference over temperature

Typical applications

• LED Lamps/ LED Lighting Fixtures/ Low Output Voltage Applications, SEPIC Topology

More information

• Datasheet
• IC product information