Texas Instruments (TI) has introduced three new DC/DC LED drivers that simplify white colour tuning for high-colour rendering and ultra-low dimming in professional-grade indoor and outdoor LED lighting applications. The TPS92660 two-string LED driver and TPS92640/1 synchronous buck controllers look to address the challenges of precise colour and brightness control lighting that designers face in creating high quality light engines for commercial area lighting, including architectural and retail displays, as well as LED-based projection systems and automotive running lights.
The TPS92660 is an 80-V input voltage, two-string LED driver consisting of one DC/DC buck regulator and one linear channel for two-colour, typically white plus red, LED mixing. Using the I2C interface and one-time programmable ROM, a lighting manufacturer can precisely tune the white correlated color temperature (CCT) and brightness of the luminaire during production to deliver exceptional lumen quality required in area, retail and architectural lighting. This method of colour tuning eliminates the need for expensive binned LEDs, reducing system costs. Analogue or pulse width modulation (PWM) input signals can be used for brightness and colour adjustment after ROM programming.
The TPS92640 and TPS92641 are 85-V input voltage, adjustable frequency, synchronous buck DC/DC LED controllers with industry-leading contrast ratios that deliver smooth, deep dimming profiles required in indoor/outdoor area lighting and LED projectors. The controllers accept analog and PWM inputs resulting in dimming ratios of 500:1 and 2500:1, respectively. Continuous-conduction mode operation preserves dimming linearity, which enables the TPS92640/1 to provide true analog “dim to zero” capability. The TPS92641 adds one input and one output pin for 20,000:1 ratio parallel shunt FET dimming.
For intelligent lighting systems, the TPS92660 and TPS92640/1 can be paired with TI’s 16-bit ultra-low power MSP430 microcontrollers for dimming control.