Constant current and constant voltage IC meets LED lighting demands
ON Semiconductor has announced a constant current and constant voltage IC which allows precise, wide range dimming in modern LED lighting applications, says the company.
The QR PSR PWM controllers are for LED lighting with power factor control (PFC) function. The dimmable NCL30386 and the non-dimmable NCL30388 provide options for designers of LED lighting units such as luminaires used in office and industrial building applications.
Both devices are high power factor (PF), single stage, constant current (CC) and constant voltage (CV) primary side regulated (PSR) pulse width modulation (PWM) controllers for flyback, buck-boost or sepic power topologies. They operate in quasi-resonant (QR) mode to achieve efficiency levels that exceed those stipulated in power standards, such as the EU’s Ecodesign, Energy Star and the NEMA SSL regulations.
The integrated digital PFC algorithm ensures a PF of greater than 0.95 and total harmonic distortion (THD) of less than 10 per cent across a universal input voltage range. Integrated high voltage start-up current source ensures fast start-up, low standby power and wide range operation at the output. Current and voltage are regulated via a digital PSR CC/CV loop control, typically achieving ± two per cent, to give uniform lighting brightness under all conditions, says ON Semiconductor.
The devices operate from a VCC range of 9.2 to 26V DC. Valley lock-out and frequency foldback ensure high efficiency across the entire voltage range, assures ON Semiconductor. The design is simplified with the inclusion of safety features such as brown-out and over-voltage protection plus the ability to detect short circuits in the output, winding and diode.
The NCL30386 and the NCL30388 do not require many external components to complete the design, reducing time-to-market, bill of materials cost and also reducing the space required.
The NCL30386’s dimming features include the option for either linear or quadratic dimming curves. The wide analogue dimming range is controlled by two dedicated analogue / PWM control pins that allow for precise dimming with a 0.5 per cent minimum dimming ratio – and no audible noise present.