Multiphase Booster LED Driver for Automotive Front Lighting NCV78702 The NCV78702 is a singlechip and high efficient booster for smart Power ballast and LED Driver designed for automotive front lighting www.onsemi.com applications like high beam, low beam, DRL (daytime running light), turn indicator, fog light, static cornering, etc. The NCV78702 is in particular designed for high current LEDs and with NCV78723 (dual channel buck)/713 (single channel) provides a complete solution to 20 drive multiple LED strings of upto 60 V. It includes a currentmode 1 24 1 voltage boost controller which also acts as an input filter with a QFNW24 TSSOP20 minimum of external components. The available output voltage can be MW SUFFIX DE SUFFIX customized. Two devices NCV78702 can be combined and the booster CASE 484AA CASE 948AB circuits can operate together to function as a multiphase booster (2phase, 3 phase, 4phase) in order to further optimize the filtering effect of the booster and lower the total application BOM cost for MARKING DIAGRAMS higher power. Thanks to the SPI programmability, one single hardware configuration can support various application platforms. N7020 N702x Features ALYW ALYW Single Chip Multiphase Booster High Overall Efficiency N702 = Specific Device Code Minimum of External Components A = Assembly Location L = Wafer Lot Active Input Filter with Low Current Ripple from Battery Y = Year Integrated Boost Controller W = Work Week = PbFree Package Programmable Input Current Limitation High Operating Frequencies to Reduce Inductor Sizes (Note: Microdot may be in either location) PCB Trace for Current Sense Shunt Resistor is Possible Low EMC Emission ORDERING INFORMATION SPI Interface for Dynamic Control of System Parameters See detailed ordering and shipping information on page 31 of Fail Save Operating (FSO) Mode, StandAlone Mode this data sheet. Integrated Failure Diagnostic Typical Applications High Beam Low Beam DRL Position or Park Light Turn Indicator Fog Static Cornering Semiconductor Components Industries, LLC, 2016 1 Publication Order Number: January, 2021 Rev. 3 NCV78702/DNCV78702 TYPICAL APPLICATION SCHEMATIC V Batt (after rev. pol. prot.) C BST IN D1 Vboost L1 VBOOSTDIV C BST RD1 C BC2 VGATE 1 T1 IBSTSENSE 1+ C BC1 R BC1 R SENSE 1 RD2 COMP IBSTSENSE 1 ON Semiconductor Phase 1 C BB LED driver VBB L2 V of MCU CC 2 phase booster C VDRIVE D2 NCV78702 VGATE 2 VDRIVE T2 C DD R SDO IBSTSENSE 2+ VDD R SENSE 2 IBSTSENSE 2 ENABLE 1 Phase 2 C BSTSYNC /TST/TST1 FSO/ ENABLE2 SPI SCLK /TST2 SPI SDI SPI SDO SPI SCS GND GNDP PWR GND Sig GND Figure 1. Typical Application Schematic Table 1. EXTERNAL COMPONENTS Component Function Typ. Value Unit L1, L2 Booster regulator coil 10 H T1, T2 Booster regulator switching transistor e.g. NTD6416ANL D1, D2 Booster regulator diode e.g. MBR5H100MFS R SENSE1, R SENSE2 Booster regulator current sensing resistor 10 m 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