LEDFRONTHBLBREFTOBO1 Infineon

Z8F68834278 Reference design guide Automotive front light LED reference design with SEPIC topology Design overview Highlighted components This Infineon reference design guide describes a TLD5099EP Multi-topology DC-DC controller detailed implementation of an automotive front from the LITIX Power family light high beam/low beam combination using the IPD60N10S4L OptiMOS -T2 as power stage flexible multi-topology DC-DC controller switching MOSFET TLD5099EP of the LITIX Power family in current controlled buck-boost SEPIC configuration. One IPD50P04P4L-11 OptiMOS -P2 as reverse single DC-DC channel is used to drive the high battery protection MOSFET beam and low beam. The high beam can be Applications activated in conjunction with the low beam or the low beam can be activated standalone. This Automotive front light represents a cost saving approach especially suitable for entry level LED headlamps. A PWM High beam, low beam dimming feature enables furthermore control of Daytime running light, turn indicator brightness and enables derating in extreme operating conditions. State of the art diagnosis is Motorcycle headlamp provided as well as transient robustness. Highlighted design aspects Compliant EMC performance is verified according to the CISPR25 standard. Thermal performance information is given and discussed. EMC Cost Space Transient tested optimized saving pulse tested Block diagram SEPIC DC/DC battery supply PI Filter Reverse coupled Polarity Mosfet L L A B High Beam C S D to central HB activation and HBA EN/ module dimming PWM SBC TLD5099 TLE9471-3ES DC/DC controller LBA, HBK C OUT Q1 Microcontroller Low Beam LBK Temperatures T Binning focus of this reference design User Guide Please read the Important Notice and Warnings at the end of this document Rev.1.00 www.infineon.com page 1 of 70 June 2020 Reference design guide Automotive front light LED reference design with SEPIC topology Table of contents Table of contents Table of contents .............................................................................................................................. 2 Important Notice .............................................................................................................................. 4 1 System description ................................................................................................................... 5 1.1 Design specifications............................................................................................................................... 5 2 System design .......................................................................................................................... 7 2.1 TLD5099EP constant current controller ................................................................................................. 8 2.1.1 Power supply .................................................................................................................................... 10 2.1.2 Switching frequency & spread spectrum ........................................................................................ 10 2.1.3 Output current configuration .......................................................................................................... 11 2.1.4 Switch current sense ........................................................................................................................ 13 2.1.5 PWM dimming .................................................................................................................................. 13 2.1.5.1 External PWM dimming ............................................................................................................... 13 2.1.5.2 Embedded PWM dimming .......................................................................................................... 14 2.1.6 Compensation network ................................................................................................................... 14 2.1.7 Overvoltage protection .................................................................................................................... 15 2.2 SEPIC power stage and input filter ....................................................................................................... 16 2.2.1 Passive components ........................................................................................................................ 17 2.2.2 Switching MOSFET ........................................................................................................................... 22 2.2.2.1 Switching losses .......................................................................................................................... 22 2.2.2.2 Conduction losses ....................................................................................................................... 27 2.2.2.3 Simulated losses ......................................................................................................................... 28 2.2.2.4 Thermal considerations .............................................................................................................. 30 2.2.3 Switching diode ................................................................................................................................ 31 2.2.4 Input filter ......................................................................................................................................... 31 2.3 High beam activation, PWM dimming and output filter ...................................................................... 33 2.4 Reverse polarity and input protection ................................................................................................. 34 2.4.1 Ceramic transient voltage suppressor ............................................................................................ 35 2.4.2 Reverse polarity protection ............................................................................................................. 39 2.5 Layout considerations ........................................................................................................................... 40 2.5.1 Layer stackup ................................................................................................................................... 40 2.5.2 General recommendations .............................................................................................................. 40 2.5.3 Power stage and input filter ............................................................................................................ 42 2.5.4 TLD5099EP ........................................................................................................................................ 43 3 System performance ...............................................................................................................44 3.1 General operating characteristics ........................................................................................................ 44 3.1.1 Output voltage and current ............................................................................................................. 44 3.1.2 Switching node ................................................................................................................................. 45 3.1.3 PWM dimming .................................................................................................................................. 45 3.1.4 High beam activation ....................................................................................................................... 46 3.2 Transient immunity ............................................................................................................................... 47 3.2.1 Jump start ........................................................................................................................................ 47 3.2.2 Load dump ....................................................................................................................................... 48 3.2.3 Start pulses ....................................................................................................................................... 49 3.2.3.1 Hot start ....................................................................................................................................... 49 3.2.3.2 Cold start ..................................................................................................................................... 51 3.2.4 Reverse polarity ................................................................................................................................ 53 3.3 Electromagnetic compatibility ............................................................................................................. 54 User Guide 2 of 70 Rev.1.00 June 2020