Texas Instruments Incorporated (TI) introduced three new DC/DC LED drivers that simplify white color tuning for high-color 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 address the challenges of precise color 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-color, 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 color tuning eliminates the need for expensive binned LEDs, reducing system costs. Analog or pulse width modulation (PWM) input signals can be used for brightness and color 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.
The TPS92660 and TPS92640/1 join TI's diverse LED driver portfolio that includes the LM3409, LM3421/3/4 and TPS92551 DC/DC LED drivers, as well as the TPS92075, LM3447, TPS92310/11/14 AC/DC LED drivers.
Key features and benefits of TPS92660 and TPS92640/1:
TPS92660 two-string LED driver
I2C and on-time programmable ROM for trim of white CCT and lumen output eliminates need for binned LEDs.
Accepts PWM or analog dimming for brightness and color adjustment.
Integrated 3-V +/- 3 percent voltage reference can be used for housekeeping circuits.
TPS92640/1 synchronous buck controller
Analog, PWM and shunt FET dimming with 500:1, 2500:1, 20,000:1 contrast ratios.
7-V to 85-V input operating range works with a variety of LED string voltages.
Synchronous, continuous conduction mode, constant current output with simple compensation scheme provides high system efficiency and simplifies circuit design.
