Datasheet A80602, A80602-1 (Allegro) - 3

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A80602 and High Power LED Driver with Pre-Emptive Boost A80602-1 for Ultra-High Dimming Ratio and Low Output Ripple Table of Contents
Features and Benefits ... 1 PWM Dimming ... 18 Description .. 1 Pre-Emptive Boost (PEB) ... 19 Applications ... 1 Analog Dimming ... 20 Package ... 1 ADIM Mode .. 20 Selection Guide ... 2 APWM Mode .. 21 Absolute Maximum Ratings ... 2 Extending LED Dimming Ratio.. 22 Thermal Characteristics .. 2 Analog Dimming with External Voltage... 23 Typical Application – SEPIC .. 3 VDD .. 24 Functional Block Diagram ... 4 VDRV .. 24 Pinout Diagram and Terminal List ... 5 Shutdown... 24 Electrical Characteristics ... 6 Fault Detection and Protection ... 25 Functional Description ...11 FAULT Status ... 25 Enabling the IC ..11 LED String Partial-Short Detect .. 27 Powering Up: LED Detection Phase .. 12 Overvoltage Protection .. 28 Powering Up: Boost Output Undervoltage .. 14 Boost Switch Overcurrent Protection ... 29 Soft Start Function .. 14 Input Overcurrent Protection and Disconnect Switch ... 30 Frequency Selection .. 15 Setting the Input Current Sense Resistor ... 31 Synchronization .. 15 Input UVLO .. 31 Loss of External Sync Signal .. 16 Fault Protection During Operation ... 31 Switching Frequency Dithering ... 17 Package Outline Drawing .. 34 LED Current Setting .. 18 Appendix: External MOSFET Selection Guide ... 35 L2 Breakdown voltage of Q1 and D1 must be > V V IN + VOUT IN D1 VOUT ≤ 40 V L1 CC CIN Q1 ROVP C C OUT1 COUT2 DRV GATE VDRV GDRV CS PGND Vsense VC VIN OVP CVDD RPU VDD LED1 FAULT
A80602
LED2 Up to 11 WLEDs in series Up to 140 mA/ch. Combine LED ... 3 EN/PWM to drive up to 840 mA total PWM ton ≥ 0.3 µs LED6 ADIM/ APWM iLED COMP 100% AGND ISET FSET DITH PEB ADIM RZ CP R R DITH ISET R R FSET C PEB CZ DITH APWM 100kHz 0-90%
Figure 2: A80602 in SEPIC configuration where VOUT can be either higher or lower than VIN
Allegro MicroSystems, LLC 3 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com Document Outline Features and Benefits Description Applications Package Selection Guide Absolute Maximum Ratings Thermal Characteristics Typical Application – SEPIC Functional Block Diagram Pinout Diagram and Terminal List Electrical Characteristics Functional Description Enabling the IC Powering Up: LED Detection Phase Powering Up: Boost Output Undervoltage Soft Start Function Frequency Selection Synchronization Loss of External Sync Signal Switching Frequency Dithering LED Current Setting PWM Dimming Pre-Emptive Boost (PEB) Analog Dimming ADIM Mode APWM Mode Extending LED Dimming Ratio Analog Dimming with External Voltage VDD VDRV Shutdown Fault Detection and Protection FAULT Status LED String Partial-Short Detect Overvoltage Protection Boost Switch Overcurrent Protection Input Overcurrent Protection and Disconnect Switch Setting the Input Current Sense Resistor Input UVLO Fault Protection During Operation Package Outline Drawing Appendix: External MOSFET Selection Guide