Apr 16 2008
Texas Instruments Incorporated (TI) introduced today a 16-channel, 50 mA constant-current sink LED driver, with an input voltage of up to 17 V. The TLC5943's integrated enhanced spectrum pulse-width modulation (PWM) improves image quality and reduces flicker noise in monochrome, multicolor and full-color LED displays, as well as LED signboards and display backlighting.
Each of the TLC5943's 16 channels has an individually adjustable 16-bit (65,536-step) grayscale PWM brightness control feature with an auto-data refresh and display repeat function. The channels are divided into four groups, and each group has an associated turn-on delay to maximize system voltage stability. All 16 channels can be adjusted with the device's 7-bit brightness control feature. A designer can use a single external resistor to set the maximum current value for all channels.
The device's brightness control feature, which can be accessed through a common 30-MHz interface, adjusts the average current levels to compensate for brightness variations that occur from one LED to the next.
The TLC5943 features two error information circuits. The device's LED open detection indicates a broken or disconnected LED at an output terminal. A thermal error flag indicates an over-temperature condition.
Key features of the TLC5943 include:
- 16-bit (65,536 steps) grayscale control with enhanced spectrum PWM
- 7-bit (128 steps) global brightness control for all channels with sink current
- VCC = 3.0 V to 5.5 V
- Constant current accuracy:
- Channel-to-channel = +/-1.5 percent
- Device-to-device = +/-3 percent
- 30-MHz data transfer rate
- Noise reduction:
- 4-channel grouped delay to prevent in-rush current