IS31FL3237 36-CHANNEL LED DRIVER WITH 16-BIT PWM November 2021 GENERAL DESCRIPTION FEATURES The IS31FL3237 is an LED driver with 36 constant 2.7V to 5.5V VCC supply current channels. Each channel can be pulse width Pin to pin with IS31FL3236/IS31FL3236A (QFN-44, modulated (PWM) by 16 bits for smooth LED 5mm5mm) brightness control. In addition, each channel has an 1MHz I2C interface, automatic address increment 8-bit output current control register which allows fine function with readout function tuning the current for rich RGB color mixing, e.g., a Four selectable I2C addresses pure white color LED application. The maximum output Accurate color rendition current of each channel is 38mA, which can be - Selectable 8-bit/10-bit/12-bit/16-bit PWM adjusted by one 8-bit global control register. - 8-bit dot correction Proprietary programmable technology is used to - 8-bit global current adjust minimize audible noise caused by MLCC decoupling Open/Short detect function capacitors. All registers can be programmed via a high 62kHz PWM frequency (8-bit PWM) speed I2C (1MHz). Temperature detect function The IS31FL3237 can be shut down with minimum EMI Reduction Technology current consumption by either pulling the SDB pin low - Spread spectrum or by using the software shutdown feature. - Selectable Phase Delay The IS31FL3237 is available in QFN-44 (5mm5mm) - Selectable 180 degree Clock Phase package. It operates from 2.7V to 5.5V over the -40C to +125C temperature range temperature range of -40C to +125C. QFN-44 (5mm5mm) package APPLICATIONS AI-speakers and smart home devices LED in home appliances LED display for hand-held devices Lumissil Microsystems www.lumissil.com 1 Rev. E, 10/15/2021 IS31FL3237 TYPICAL APPLICATION CIRCUIT *Note 1 *Note 1 V =V CC Battery 38 V =V LED+ Battery VCC 43 37 OUT1 1 F AD 0.1 F 44 OUT2 *Note 2 1 V OUT3 IH 2k 2k 41 SDA 42 Micro IS31FL3237 SCL Controller 36 SDB 100k 0.1 F 33 OUT34 40 34 ISET OUT35 RISET 35 3.3k 17 OUT36 GND 39 Figure 1 Typical Application Circuit *Note 1 *Note 1 *Note 3 V =5V CC 38 VLED+=5V 33 VCC 43 37 OUT1 1 F AD 91 0.1 F 44 OUT2 *Note 2 33 1 V OUT3 IH 2k 2k 41 SDA 42 Micro IS31FL3237 SCL Controller 36 SDB 100k 0.1 F 33 33 OUT34 91 40 34 ISET OUT35 RISET 33 35 3.3k 17 OUT36 GND 39 Figure 2 Typical Application Circuit (V =5V) CC Note 1: V can be higher than VCC voltage, for example, V +=5V, V =3.3V. LED+ LED CC Note 2: V is the high level voltage for IS31FL3237, which is usually same as V of Micro Controller, e.g. if V of Micro Controller is 3.3V, V = IH CC CC IH 3.3V. If V = 5V and V is lower than 2.8V, recommend to add a level shift circuit. CC IH 2 Note 3: These optional resistors are for offloading the thermal dissipation (P=I R) away from the IS31FL3237. Note 4: The output current is set up to 23mA when R = 3.3k. The maximum global output current can be set by external resistor, R . ISET ISET Please refer to the detail application information in R section. ISET Lumissil Microsystems www.lumissil.com 2 Rev. E, 10/15/2021