NCV78703 Multiphase Booster LED Driver for Automotive Front Lighting The NCV78703 is a singlechip and high efficient booster for smart www.onsemi.com Power ballast and LED Driver designed for automotive front lighting applications like high beam, low beam, DRL (daytime running light), turn indicator, fog light, static cornering, etc. The NCV78703 is in particular designed for high current LEDs and with NCV78723 (dual channel buck)/713 (single channel) provides a complete solution to 1 24 24 1 drive multiple LED strings of upto 60 V. It includes a currentmode QFN24 QFN24 voltage boost controller which also acts as an input filter with a MW SUFFIX MW SUFFIX minimum of external components. The available output voltage can be CASE 485L CASE 485CS customized. Two devices NCV78703 can be combined and the booster circuits can operate together to function as a multiphase booster (2phase, 3 phase, 4phase, 5phase, 6phase) in order to further MARKING DIAGRAM optimize the filtering effect of the booster and lower the total application BOM cost for higher power. Thanks to the SPI N7031 programmability, one single hardware configuration can support ALYW various application platforms. Features Case 485L Single Chip Multiphase Booster N787030 High Overall Efficiency AWLYYWW Minimum of External Components Active Input Filter with Low Current Ripple from Battery Case 485CS Integrated Boost Controller Programmable Input Current Limitation N703 = Specific Device Code or N78703 High Operating Frequencies to Reduce Inductor Sizes A = Assembly Location PCB Trace for Current Sense Shunt Resistor is Possible L or WL = Wafer Lot Y or YY = Year Low EMC Emission W or WW = Work Week SPI Interface for Dynamic Control of System Parameters = PbFree Package Fail Save Operating (FSO) Mode, StandAlone Mode (Note: Microdot may be in either location) Integrated Failure Diagnostic Typical Applications ORDERING INFORMATION High Beam See detailed ordering and shipping information on page 34 of Low Beam this data sheet. DRL Position or Park Light Turn Indicator Fog Static Cornering Semiconductor Components Industries, LLC, 2016 1 Publication Order Number: January, 2016 Rev. 0 NCV78703/DNCV78703 TYPICAL APPLICATION SCHEMATIC V Batt (after rev. pol. prot.) C BST IN Vboost L1 VBOOSTDIV RD1 C BST C BC2 VGATE 1 T1 IBSTSENSE 1+ C BC1 R BC1 R SENSE1 RD2 COMP IBSTSENSE 1 Phase 1 ON Semiconductor C BB V of MCU CC LED driver VBB L2 3 phase booster C DRIVE VGATE 2 VDRIVE T2 R SDO NCV78703 C DD IBSTSENSE 2+ VDD R SENSE2 IBSTSENSE 2 ENABLE1,3 Phase 2 C BSTSYNC/TST/TST1 L3 FSO/ENABLE2 VGATE 3 T3 SPI SCLK/TST2 SPI SDI IBSTSENSE 3+ SPI SDO R SENSE3 SPI SCS IBSTSENSE 3 Phase 3 GND GNDP PWR GND Sig GND Figure 1. Typical Application Schematic Table 1. EXTERNAL COMPONENTS Component Function Typ. Value Unit L1, L2, L3 Booster regulator coil 10 H T1, T2, T3 Booster regulator switching transistor e.g. NTD6416ANL D1, D2, D3 Booster regulator diode e.g. MBR5H100MFS R SENSE1, R SENSE2, Booster regulator current sensing resistor 10 m R SENSE3 C BST Booster regulator output capacitor 0.44 F/W C BB V decoupling capacitance (Note 1) 1 F BB C VDRIVE Capacitor for V regulator 1 F DRIVE C VDRIVE ESR ESR of V capacitor max. 200 m DRIVE C DD V decoupling capacitor 1 F DD C DD ESR ESR of V capacitor max. 200 m DD R SDO SPI pullup resistor 1 k C BC1 Booster compensation network See Booster Compensator Model section C BC2 Booster compensation network See Booster Compensator Model section R BC1 Booster compensation network See Booster Compensator Model section RD1 Booster output voltage feedback divider (Note 2) 107 (1% tolerance) k RD2 Booster output voltage feedback divider (Note 2) 3.24 (1% tolerance) k 1. The value represents a potential initial startup value on a generic application. The actual size of the boost capacitor depends on the application defined requirements (such as power level, operating ranges, number of phases) and transient performances with respect to the rest of BOM. Please refer to application notes and tools provided by ON Semiconductor for further guidance. The chosen value must be validated in the application. 2. Proposed values. Divider ratio (BSTDIV RATIO) has to be 34. Tolerance of the resistors has to be 1% to guarantee Booster parameters (see Table 12). www.onsemi.com 2