IS31FL3246 36-CHANNEL LED DRIVER October 2021 GENERAL DESCRIPTION FEATURES IS31FL3246 is comprised of 36 constant current 2.7V to 5.5V supply channels, each channel can be pulse width modulated Pin to Pin with IS31FL3236A/IS31FL3237 (PWM) by total 8 bits+10 bits (261890 steps) for (QFN-44, 5mm5mm) smooth LED brightness control or color mixing control, I2C with register address automatic increment 8 bits PWM (LFP) operate at 127Hz (can be disabled), Four selectable I2C addresses 10 bits (HFP) operate at 32kHz, to minimize the SDB rising edge reset I2C module audible noise. The output current of each channel can Resistor sets operating current of 25mA (Max.) be set at up to 25mA (Max.), all channels are grouped as G group(OUT1, OUT4, OUT7...), R group (OUT2, Accurate color rendition OUT5, OUT8...) , B group (OUT3, OUT6, OUT9...) and - Three 8-bit global DC current adjust each group has a 8 bits output current control register - 8-bit DC current adjust for all green channels which allows fine tuning the current for rich global RGB - 8-bit DC current adjust for all red channels color mixing. - 8-bit DC current adjust for all blue channels Proprietary programmable technology is used to - Each channel total 8-bit+10-bit PWM (261890 minimize audible noise caused by MLCC decoupling steps) capacitors. All registers can be programmed via a high - 8-bit PWM at 127Hz/254Hz/508Hz (LFP) speed I2C bus interface (1MHz). -10-bit/8-bit PWM at 32kHz (8-bit mode can be at 64kHz or 128kHz, HFP) The chip can be turned off by pulling the SDB pin low Group dimming to reduce RGB coding or by using the software shutdown feature to reduce power consumption. The rising edge of the SDB pin will EMI reduction technology reset the I2C bus module. - Selectable 6 phase delay - Selectable 180 degree clock phase IS31FL3246 is available in QFN-44 (5mm5mm) and -40C to +125C extended industrial temperature eTQFP-48. It operates from 2.7V to 5.5V over the range temperature range -40C to +125C. APPLICATIONS Hand-held devices for LED display LED in home appliances Lumissil Microsystems www.lumissil.com 1 Rev. C, 10/08/2021 IS31FL3246 TYPICAL APPLICATION CIRCUIT *Note 1 *Note 1 V = V V = V CC Battery LED+ Battery VCC OUT1 G1 1F AD 0.1 F OUT2 R1 *Note 2 V OUT3 B1 BUS 2k 2k SDA Micro IS31FL3246 SCL Controller SDB 100k 0.1F OUT34 G12 ISET OUT35 R12 RISET 3.3k OUT36 B12 GND Figure 1 Typical Application Circuit (V =V ) CC Battery *Note 1 *Note 1 *Note 3 V = 5V CC V = 5V LED+ 33 VCC OUT1 G1 1F AD 91 0.1F OUT2 R1 *Note 2 33 V OUT3 B1 BUS 2k 2k SDA Micro IS31FL3246 SCL Controller SDB 100k 0.1F 33 OUT34 G12 91 ISET OUT35 R12 RISET 33 3.3k OUT36 B12 GND Figure 2 Typical Application Circuit (V =5V) CC can be the same or less than VCC voltage. Note 1: V LED+ Note 2: V is the pull up voltage for the IS31FL3246 I2C interface, which is usually the same as the micro controller s V . If the IS31FL3246 BUS CC V = 5V and V is lower than 2.8V, recommend using an I2C level shift circuit to avoid a high shut down current (I ). For example with V = CC BUS SD BUS 1.8V, if the IS31FL3246 V = 4V the I = 43A (Typ.) or if V = 5V the I =111A (Typ.). CC SD CC SD 2 Note 3: These optional resistors are for offloading the thermal dissipation (P= I R) away from the IS31FL3246(values are for V = 5V). LED+ 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. C, 10/08/2021