IS31FL3746B 184 DOTS MATRIX LED DRIVER WITH 12MHZ SPI December 2018 GENERAL DESCRIPTION FEATURES The IS31FL3746B is a general purpose 18n (n=1~4) Supply voltage range: 2.7V to 5.5V LED Matrix programmed via 12MHz SPI interface. 18 current sinks Each LED can be dimmed individually with 8-bit PWM Support 18n (n=1~4) LED matrix configurations data and 8-bit DC scaling data which allowing 256 Accurate color rendition steps of linear PWM dimming and 256 steps of DC - 8-bit PWM current adjustable level. - 8-bit dot correction Additionally each LED open state can be detected, - 8-bit global current adjust IS31FL3746B store the open information in Open- SDB rising edge reset SPI module Registers. The Open Registers allowing MCU to read 29kHz PWM frequency out via SPI, inform MCU whether there are LEDs open 12MHz SPI interface or short LEDs. Individual open and short error detect function The IS31FL3746B operates from 2.7V to 5.5V and 180 degree phase delay operation to reduce features a very low shutdown and operational current. power noise IS31FL3746B is available in QFN-32 (4mm4mm) Spread spectrum package. It operates from 2.7V to 5.5V over the De-ghost temperature range of -40C to +125C. QFN-32 (4mm4mm) package APPLICATIONS Hand-held devices for LED display Gaming device (Keyboard, Mouse etc.) LED in white goods application TYPICAL APPLICATION CIRCUIT *Note 3 5V 3.3V 29 19 VCC VIO 1 F 0.1 F 0.1 F SW1 SW2 SW3 SW4 *Note 3 *Note 2 3.3V 51 28 23 SW1 CS18 MOSI 27 21 SW2 20 SCK 26 CS17 22 SW3 Micro CS 25 20 *Note 4 Controller 24 SW4 CS16 MISO 20 IS31FL3746B SDB 32 CS1 100k 0.1 F 1 51 CS2 CS3 20 31 CS2 ISET CS17 17 20 RISET CS1 10k 9 CS18 18 GND 30 Figure 1 Typical Application Circuit: 24 RGBs Lumissil Microsystems www.lumissil.com 1 Rev. A, 12/11/2018 IS31FL3746B TYPICAL APPLICATION CIRCUIT (CONTINUED) *Note 3 5V 3.3V 29 19 VCC VIO 1 F 0.1 F 0.1 F SW1 SW2 SW3 SW4 *Note 3 *Note 2 3.3V 20 28 23 SW1 CS18 MOSI 27 21 SW2 20 SCK 26 CS17 22 SW3 Micro CS 25 20 *Note 4 Controller 24 SW4 CS16 MISO 20 IS31FL3746B SDB 32 CS1 100k 0.1 F 1 CS2 20 CS3 20 31 CS2 ISET CS17 17 20 RISET CS1 10k 9 CS18 18 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 CC resistors. Note 3: The V of SPI 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 VCC of MCU is 5V, V =5V. IO IO Note 4: MISO V =V . OH IO Lumissil Microsystems www.lumissil.com 2 Rev. A, 12/11/2018