AL58221

Description

The AL58221 is a 12-channel (R/G/B x 4), constant-current, Adaptive Pulse Density Modulation (APDM) LED driver which operates over a 3V~5.5V input voltage range. The device provides 12 open-drain constant-current sinking outputs that are rated to 24V and delivers up to 60mA of high-accuracy current to each string of LED. Each channel’s average output current can be individually programmable through a digital interface. The current at each output is set by three external current-setting resistors.

The AL58221 features a 10MHz double-edge trigger data clock input to reduce EMI. It offers a 2-wire serial interface to send grayscale data, control commands including 16/14/12/8-bit grayscale selection, grayscale clock frequency division selection, output polarity selection for high-power LED driving, output Trise and Tfall timing selection, current output waveform selection, and internal-latch function.

The device provides an adaptive pulse density modulation method to increase the visual refresh rate up to 1000 Hz @ 16-bit grayscale. It reduces flickers and provides output current bilateral processing for EMI reduction.

The AL58221 utilizes a clock duty recovery technique and pulse retiming to support longer distance connection and multiple devices’ cascading applications. It also provides typical ±1% channel-tochannel LED current accuracy. Additional features include a ±0.1% regulated output current capability and fast output transient response.

The AL58221 is available in the TSSOP-24EP (Type A1-B) package and is specified over the -40°C to +85°C ambient temperature range.

Feature(s)

• Input Voltage VDD: 3V to 5.5V
• Constant Current Output Range
  • 3~60mA@5V
  • 3~35mA@3.3V
• 12 Constant-Current Sink (R/G/B x 4) Output Channels
  • RGB Output Current setting by 3 external resistors
  • 24V Rated output channels for long LED strings
  • ±1% (typ.) LED Current accuracy between channels
  • ±2% (typ.) LED Current accuracy between devices
  • 16 / 14 / 12 / 8-bit grayscale selection
  • Grayscale clock source selection: internal or external
  • PWM or APDM control selection
  • Programmable Output Current Trise / Tfall time
  • Output Current Bilateral Processing for EMI reduction
• Diagnosis and Protections
  • Built-in internal grayscale clock supports refresh rate >1000Hz@16-bit grayscale, >256KHz@8-bit grayscale
  • Internal Grayscale clock frequency selection for High-Power LED driving application (min. 33.6KHz)
• 2-Wire Serial Interface (DI, DCKI)
  • 20Mbps (max.) ~ 140 Kbps(min.) data rate for EMI reduction data transfer
  • Cascaded capability (Max 1,030 devices)
  • Clock duty recovery for cascading applications
  • Schmitt trigger input
• Totally Lead-Free & Fully RoHS Compliant (Notes 1& 2)
• Halogen and Antimony Free. “Green” Device (Note 3)
• For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/104/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. https://www.diodes.com/quality/product-definitions/

Application(s)

• Indoor and outdoor LED video displays
• Architectural and decorative lighting
• Digital signage and billboard applications
• LCD display backlighting
• Transportation signs