IS31FL3248 48-Channel LED Driver ICs

Lumissil's IS31FL3248 is an ideal LED driver for applications with many LEDs to be controlled by a simple four-wire serial bus running at 33 MHz. The SDI and SDO pins allow more than one device to be connected in a daisy chain for LED control using one serial interface. An external resistor sets the current for all 48 channels up to 33 mA; software registers further adjust the three-channel grouping current and/or the individual channel current. An 8-bit register sets the brightness level for each grouping and a 6-bit register adjusts the brightness deviation between channels.

The IS31FL3248 uses proprietary programmable algorithms to minimize system noise generation and improve the overall EMI system performance. Applying PWM switching to the LED outputs can be particularly troublesome with regard to EMI. To optimize EMI performance, the IS31FL3248 includes a programmable spread spectrum function to lower the PWM clock’s peak electromagnetic energy by spreading it over a wide frequency range. In addition, a selectable 180-degree phase delay of the output-channels reduces power supply inrush current which further helps reduce EMI.

The IS31FL3248 also has real-time LED open (LOD) and short (LSD) diagnostic capabilities. When enabled, the LED open or short condition can be detected in real time with the status information stored in a system-readable register.