With adaptive pulse density modulation (APDM) for higher refresh rates, precise current regulation, and EMI reduction, it offers 24V open-drain outputs and supports cascading up to 1,030 devices.
Diodes Incorporated has launched the AL58221, a 12-channel constant-current LED driver. The device offers 12 open-drain outputs, is rated at 24V, and can sink up to 60mA of current. It provides channel-to-channel current accuracy of ±1% and an output current tolerance of ±0.1%, suitable for applications requiring precise current regulation.
The key features include:
- Operates with an input voltage range of 3V to 5.5V
- Utilizes adaptive pulse density modulation (APDM)
- Minimizes IOUT distortion
This modulation supports higher refresh rates, enhancing the driver’s performance in a variety of LED applications. It is designed for use in digital signage, variable messaging signs, architectural lighting, and LCD backlighting systems. LED current is programmed using three external resistors for RGB settings, with each channel’s output current controlled via a digital interface. The device includes a 10MHz double-edge triggered data clock input that helps reduce electromagnetic interference (EMI). The two-wire serial interface transmits grayscale data to function-control registers, managing settings for grayscale resolution, clock frequency, current waveform, and internal latch functions.
APDM technology allows the AL58221 to achieve a visual refresh rate of over 1,000Hz at 16-bit grayscale and over 256kHz at 8-bit grayscale, reducing flicker. The driver also uses pulse retiming for long-distance connections and EMI mitigation. Its serial interface allows cascading up to 1,030 devices for larger applications. Diodes also offers the AL58263, a 16-channel driver designed for larger, higher-resolution display applications. The AL58263 features 16-bit PWM grayscale dimming control. Both the AL58221 and AL58263 are available in TSSOP-24EP (Type A1-B) packages, priced at $0.37 and $0.47, respectively, for orders of 1,000 pieces.
