Datasheet A80603, A80603-1 (Allegro) - 3

link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 2 link to page 2 link to page 3 link to page 4 link to page 5 link to page 6 link to page 9 link to page 9 link to page 10 link to page 12 link to page 12 link to page 13 link to page 14 link to page 14 link to page 15 link to page 15 link to page 16 link to page 16 link to page 17 link to page 18 link to page 19 link to page 20 link to page 21 link to page 21 link to page 22 link to page 22 link to page 22 link to page 23 link to page 24 link to page 24 link to page 25 link to page 25 link to page 28 link to page 29
A80603 and LED Driver with Pre-Emptive Boost A80603-1 for Ultra-High Dimming Ratio and Low Output Ripple Table of Contents
Features and Benefits ... 1 Clock Out Function.. 15 Description .. 1 LED Current Setting .. 16 Applications ... 1 PWM Dimming ... 16 Package ... 1 Pre-Emptive Boost (PEB) ... 17 Selection Guide ... 2 Analog Dimming with APWM Pin... 18 Absolute Maximum Ratings ... 2 Extending LED Dimming Ratio.. 19 Thermal Characteristics .. 2 Analog Dimming with External Voltage... 20 Typical Application – SEPIC .. 3 VDD .. 21 Functional Block Diagram ... 4 Shutdown... 21 Pinout Diagram and Terminal List ... 5 Fault Detection and Protection ... 22 Electrical Characteristics ... 6 LED String Partial-Short Detect .. 22 Functional Description .. 9 Overvoltage Protection .. 22 Enabling the IC ... 9 Boost Switch Overcurrent Protection ... 23 Powering Up: LED Detection Phase .. 10 Input Overcurrent Protection and Disconnect Switch ... 24 Powering Up: Boost Output Undervoltage .. 12 Setting the Current Sense Resistor ... 24 Soft Start Function .. 12 Input UVLO .. 25 Frequency Selection .. 13 Fault Protection During Operation ... 25 Synchronization .. 14 Fault Recovery Mechanism .. 28 Loss of External Sync Signal .. 14 Package Outline Drawing .. 29 Switching Frequency Dithering ... 15 L2 VSW = VIN + VOUT ≤ 50 V V D1 Breakdown voltage > 60 V IN D1 L1 CC C L1 & L2 may be either IN separate or integrated ROVP COUT1 COUT2 GATE SW OVP Vsense Vc Vin CVDD R VDD PU VDD LED1 FAULT A80603 LED2 Up to 4 WLEDs in series EN (VOUT < 15 V) LED3 Up to 120 mA/ch PWM t PWM ON ≥ 0.3 µs LED4 APWM COMP CLKOUT APWM 100 kHz 0-90% AGND ISET FSET DITH PEB R C Z P R RDITH ISET RFSET C RPEB DITH CZ
Figure 2: Typical application showing SEPIC configuration for flexible input/output voltage ratio
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 Clock Out Function LED Current Setting PWM Dimming Pre-Emptive Boost (PEB) Analog Dimming with APWM Pin Extending LED Dimming Ratio Analog Dimming with External Voltage VDD Shutdown Fault Detection and Protection LED String Partial-Short Detect Overvoltage Protection Boost Switch Overcurrent Protection Input Overcurrent Protection and Disconnect Switch Setting the Current Sense Resistor Input UVLO Fault Protection During Operation Fault Recovery Mechanism Package Outline Drawing