LM3435SQX/NOPB

LM3435 www.ti.com SNVS724C – JUNE 2011 – REVISED MAY 2013 Compact Sequential Mode RGB LED Driver with I2C Control Interface Check for Samples: LM3435 FEATURES KEY SPECIFICATIONS • • • • • 1 23 • • • • • • Sequential RGB Driving Mode Low Component Count and Small Solution Size Stable with Ceramic and Other Low ESR capacitors, No Loop Compensation Required Fast Transient Response Programmable Converter Switching Frequency up to 1 MHz MCU Interface Ready With I2C Bus Peak Current Limit Protection for the Switcher LED Fault Detection and Reporting via I2C Bus • • • • • Support up to 2A LED current Typical ±3% LED current accuracy Integrated N-Channel main and P-Channel synchronous MOSFETs 3 Integrated N-Channel current regulating pass switches LED Currents programmable via I2C bus independently Input voltage range: 2.7 – 5.5 V Thermal shutdown Thermally enhanced WQFN package APPLICATIONS DESCRIPTION • • The LM3435, a Synchronously Rectified non-isolated Flyback Converter, features all required functions to implement a highly efficient and cost effective RGB LED driver. Different from conventional Flyback converter, LEDs connect across the VOUT pin and the VIN pin through internal passing elements at corresponding LED pins. Thus, voltage across LEDs can be higher than, equal to or lower than the input supply voltage. Li-ion Batteries/USB Powered RGB LED Driver Pico/Pocket RGB LED Projector TYPICAL APPLICATION Load current to LEDs is up to 2A with voltage across LEDs ranging from 2.0V to 4.5V. Integrated NChannel main MOSFET, P-Channel synchronous MOSFET and three N-Channel current regulating pass switches allow low component count, thus reducing complexity and minimize board size. The LM3435 is designed to work exceptionally well with ceramic output capacitors with low output ripple voltage. Loop compensation is not required resulting in a fast load transient response. Non-overlapping RGB LEDs are driven sequentially through individual control. Output voltage hence can be optimized for different forward voltage of LEDs during the nonoverlapping period. I2C™ interface eases the programming of the individual RGB LED current up to 1,024 levels per channel. The LM3435 is available in the thermally enhanced 40-pin WQFN package. 1 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. I C is a trademark of NXP. All other trademarks are the property of their respective owners. 2 2 3 PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2011–2013, Texas Instruments Incorporated LM3435 SNVS724C – JUNE 2011 – REVISED MAY 2013 www.ti.com CONNECTION DIAGRAM Figure 1. Top View 40-Pin WQFN See RSB0040A Package Pin Descriptions 2 Pin Name Type Description Application Information 1, 2, 38, 39, 40 PGND Ground Power Ground Ground for power devices, connect to GND. 3 CG Output GREEN LED capacitor Connect a capacitor to Ground for GREEN LED. Minimum 1nF. 4 CB Output BLUE LED capacitor Connect a capacitor to Ground for BLUE LED. Minimum 1nF. 5 CR Output RED LED capacitor Connect a capacitor to Ground for RED LED. Minimum 1nF. 6 IREFG Output Current Reference for GREEN LED Connect a resistor to Ground for GREEN LED current reference generation. 7 IREFB Output Current Reference for BLUE LED Connect a resistor to Ground for BLUE LED current reference generation. 8 IREFR Output Current Reference for RED LED Connect a resistor to Ground for RED LED current reference generation. 9 GND Ground Ground 10, 29 SGND Ground I2C Ground Ground for I2C control, connect to GND. 2 11 SVDD Power I C VDD VDD for I2C control. 12 SDATA Input / Output DATA bus Data bus for I2C control. 13 SCLK Input CLOCK bus Clock bus for I2C control. 14, 15, 16, 17, 37 VIN Power Input supply voltage Supply pin to the device. Nominal input range is 2.7V to 5.5V. 18 GCTRL Input GREEN LED control On/Off control signal for GREEN LED. Internally pull-low. 19 BCTRL Input BLUE LED control On/Off control signal for BLUE LED. Internally pull-low. 20 RCTRL Input RED LED control On/Off control signal for RED LED. Internally pull-low. 21, 22 RLED Output RED LED cathode Connect RED LED cathode to this pin. 23, 24 BLED Output BLUE LED cathode Connect BLUE LED cathode to this pin. 25, 26 GLED Output GREEN LED cathode Connect GREED LED cathode to this pin. 27 FAULT Output Fault indicator Pull-up when LED open or short is being detected. Submit Documentation Feedback Copyright © 2011–2013, Texas Instruments Incorporated Product Folder Links: LM3435 LM3435 www.ti.com SNVS724C – JUNE 2011 – REVISED MAY 2013 Pin Descriptions (continued) Pin Name Type Description Application Information 28 EN Input Enable pin Internally pull-up. Connect to a voltage lower than 0.2 x VIN to disable the device. 30, 31, 32 VOUT Input / Output Output voltage Connect anodes of LEDs to this pin. 33 RT Input ON-time control An external resistor connected from VOUT to this pin sets the main MOSFET on-time, hence determine the switching frequency. 34, 35, 36 SW Output Switch node Internally connected to the drain of the main N-channel MOSFET and the P-channel synchronous MOSFET. Connect to the output inductor. EP EP Ground Exposed Pad Thermal connection pad, connect to the GND pin. These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ABSOLUTE MAXIMUM RATINGS (1) VALUE / INPUTS VIN to GND –0.3V to 6.0V VOUT, RT to VIN –0.3V to 5.5V RLED, GLED, BLED to VIN –0.3V to 5.5V SW to GND –0.3V to 11.5V SW to GND (Transient) –2V to 13V (