Renesas Electronics Corporation

The iW3638 second-stage buck LED driver provides constant current to LEDs directly from DC power supplies. It supports a non-isolated buck converter topology to post-regulate from an off-line AC/DC converter, minimizing low frequency output ripple current and eliminating virtually all flicker in the system, even down to 1%. A wide range of DC input voltages simplifies design by enabling the use of just one second-stage driver across any commercial lighting product portfolio.

The iW3658 is a highly integrated, high-performance LED driver for easy, low-cost dimmable bulb designs up to 15W. It features an integrated FET for low BOM cost and Renesas' proprietary dimming control to enable compatibility with a wide range of dimmers, including TRIAC and digital. It also provides smooth, flicker-free dimming across a wide dimming range. Renesas' patented VCCcontrol technology used in the iW3658 removes the need for external start-up circuitry, eliminates ghosting, and provides fast start-up and consistent VCCcharging control for stable parallel lamp performance to ensure simultaneous turn-on. Full protection features in the iW3658 include Renesas' unique over-temperature protection (OTP) derating, which protects the LED driver by reducing output current drive to the LEDs during an over-temperature event.

The iW3671 front-end flyback power factor correction device provides high power factor (PF >0.9) and low THD (<20%) down to 33% load current using Renesas' PF-Boost™ technology. The device can be configured in both isolated and non-isolated configurations, as a buck, buck-boost, or flyback converter, and consumes less than 150mW no-load standby power at 230VAC. The iW3671 integrates a full range of protection features including output overvoltage, over-power, input overvoltage and undervoltage, overcurrent and sense resistor short circuit protection, open loop, and over-temperature protection. For an integrated high-voltage startup option, see theiW3677.

The iW3677 front-end flyback power factor correction device provides high power factor (PF >0.9) and low THD (<20%) down to 33% load current using Renesas'PF-Boost™technology. The device can be configured in both isolated and non-isolated configurations, as a buck, buck-boost or flyback converter and consumes less than 150mW no-load standby power at 230VAC. The iW3677 integrates a high-voltage startup device which also reduces standby power consumption during normal operation. The iW3677 integrates a full range of protection features including output overvoltage, over-power, input overvoltage and undervoltage, overcurrent and sense resistor short circuit protection, open loop and over-temperature protection. For an option without integrated high-voltage startup, seeiW3671.

The iW3688 single-stage SSL LED driver offers smooth, flicker- and shimmer-free dimming performance and exceptional compatibility with an ultra-wide range of phase-cut dimmers, including the most challenging TRIAC and digital dimmers. Renesas' patented digital algorithms eliminate more than 20 components, including the external bleeder circuit, enabling integrated active biasing for high-performance dimming at a lower BOM cost compared to conventional bleeder circuits. The iW3688 also works with off-the-shelf inductors to further reduce the BOM. Full protection features include Renesas' unique over-temperature protection (OTP) derating, which monitors the temperature inside the sealed LED bulb and seamlessly reduces the drive to the LEDs if the temperature rises above a safe operating threshold, it then restores the brightness as the temperature falls. The iW3688 integrates the temperature sensor and allows the user to configure the OTP thresholds. For higher power applications, see theiW3600andiW3605LED driver pages.