IS31FL3746A 24-RGB MATRIX LED DRIVER April 2021 GENERAL DESCRIPTION FEATURES The IS31FL3746A is a general purpose 18n (n=1~4) Supply voltage range: 2.7V to 5.5V LED Matrix programmed via 1MHz I2C compatible 18 current sinks interface. Each LED can be dimmed individually with 8- Support 18n (n=1~4) LED matrix configurations bit PWM data and 8-bit DC scaling (Color Calibration) Accurate color rendition data which allowing 256 steps of linear PWM dimming - 8-bit PWM and 256 steps of DC current adjustable level. - 8-bit dot correction Additionally each LED open and short state can be - 8-bit global current adjust detected, IS31FL3746A store the open or short SDB rising edge reset I2C module information in Open-Short Registers. The Open-Short 29kHz PWM frequency Registers allowing MCU to read out via I2C compatible 1MHz I2C-compatible interface interface. Inform MCU whether there are LEDs open or short and the locations of open or short LEDs. Individual open and short error detect function 180 degree phase delay operation to reduce power The IS31FL3746A operates from 2.7V to 5.5V and noise features a very low shutdown and operational current. Spread spectrum IS31FL3746A is available in QFN-32 (4mm4mm) De-ghost package. It operates from 2.7V to 5.5V over the QFN-32 (4mm4mm) package temperature range of -40C to +125C. APPLICATIONS Hand-held devices for LED display Gaming device (Mouse, Mouse MAT etc.) IOT device (AI speaker etc.) TYPICAL APPLICATION CIRCUIT 5V 29 VCC 25 1 F 0.1 F SW4 26 SW1 SW2 SW3 SW4 SW3 *Note 2 *Note 3 3.3V 27 19 SW2 51 VIO 28 CS18 SW1 0.1 F 20 CS17 *Note 3 3.3V 20 *Note 3 CS16 3.3V 2k 2k IS31FL3746A 23 SDA 21 Micro SCL 18 Controller 20 CS18 51 SDB 17 CS3 CS17 20 100k 0.1 F CS2 31 20 ISET CS1 22 1 ADDR1 CS2 RISET 24 32 10k ADDR2 CS1 9 GND 30 Figure 1 Typical Application Circuit: 184, 24 RGBs Lumissil Microsystems www.lumissil.com 1 Rev. C, 04/08/2021 IS31FL3746A TYPICAL APPLICATION CIRCUIT (CONTINUED) 5V 29 VCC 25 1 F 0.1 F SW4 26 SW1 SW2 SW3 SW4 SW3 *Note 2 *Note 3 3.3V 27 19 SW2 20 VIO 28 CS18 SW1 0.1 F 20 CS17 *Note 3 3.3V 20 *Note 3 CS16 2k 2k 3.3V IS31FL3746A 23 SDA 21 Micro SCL 18 Controller 20 CS18 20 SDB 17 CS3 CS17 20 100k 0.1 F CS2 20 31 ISET CS1 22 1 ADDR1 CS2 RISET 24 32 10k ADDR2 CS1 9 GND 30 Figure 2 Typical Application Circuit: 72 Mono Color LEDs Note 1: IC should be placed far away from the antenna in order to prevent the EMI. Note 2: The 20 or 51 resistors between LED and IC are only for thermal reduction, for mono red LED, if V =3.3V, dont need these resistors. CC Note 3: The V of I2C bus should be same as VIO pin. VIO pin need to connect to a reference voltage and usually it is same as the VCC of IH MCU. If VCC of MCU is 1.8V, V =1.8V, if V of MCU is 5V, V =5V. IO CC IO Lumissil Microsystems www.lumissil.com 2 Rev. C, 04/08/2021