Detailed Description

The IS3750 is an Addressable LED Controller accessed via I2C. It can control from a single LED up to a strip of 1,200 RGB LEDs. It is designed to offload the LED data timing and transmission tasks from microcontrollers and FPGAs. The chip is available in two temperature ranges: Industrial (-40ºC to +85ºC) and Extended (-40ºC to +125ºC).

The IS3750 consists of three modules: the I2C-Serial Interface, the Memory Map, and the Render.

I2C-Serial Interface Module

Data is sent via I2C from the user application (microcontroller, FPGA, single-board computer, or any I2C master) to the IS3750's internal memory map.

The IS3750 acts as an I2C slave, eliminating the need for a dedicated pin on the microcontroller, since it uses a shared bus.

The I2C interface supports Standard Mode (100kHz), Fast Mode (400kHz), and Fast Mode Plus (1MHz). A dedicated pin (I2CSPD) configures the appropriate internal filters for the selected speed.

The chip operates at a 3.3 V. Its I2C pins are 5 V tolerant, making it compatible with both 3.3 V and 5 V microcontrollers.

LED Memory Map Module

Each LEDx memory register represents the brightness of one color of a LED. The chip includes 3,600 registers, allowing control of up to 1,200 RGB addressable LEDs:

3,600 registers ÷ 3 colors = 1,200 LEDs.

LEDs with more than three colors or with non-standard color orders can also be controlled.

LED Render Module

Writing a 1 to a special register called SHOW, activates the LED Render module. This triggers a read of all LEDx registers and generates the corresponding output signal on the LED pin.

The LED pin operates at 3.3 V. When interfacing with 5 V LEDs, a buffer, Schmitt trigger, or level shifter is required to adapt it’s 3.3 V to 5 V. Refer to chapter “Hardware Example” for more details