Datasheet A80603, A80603-1 (Allegro)

A80603 and A80603-1 LED Driver with Pre-Emptive Boost for Ultra-High Dimming Ratio and Low Output Ripple FEATURES AND BENEFITS DESCRIPTION
• Automotive AEC-Q100 qualified The A80603 and A80603-1 are multi-output LED drivers that • Enhanced fault handling for ASIL B system compliance integrate a current-mode boost converter with an internal power • Wide input voltage range of 4.5 to 40 V for start/stop, switch and four current sinks. The boost converter can drive cold crank, and load dump requirements four strings of LEDs at up to 120 mA, or LED sinks can be • Fully integrated LED current sinks and boost converter paralleled together to achieve higher currents up to 480 mA total. with internal power MOSFET The devices operate from single power supply from 4.5 to • Operate in Boost or SEPIC mode for flexible output 40 V; once started, they can continue to operate down to 3.9 V. • Drives up to 11 series white LED in 4 parallel strings, at This allows the parts to withstand stop/start, cold crank, and up to 120 mA per string (VF = 3.3 V max). load dump conditions encountered in automotive systems. By • Boost switching frequency synced externally or using patented Pre-Emptive Boost control, an LED brightness programmed from 200 kHz to 2.3 MHz contrast ratio of 15,000:1 can be achieved using PWM-only • Clock-Out feature for internal switching frequency dimming at 200 Hz. Higher ratios are possible when using a • Adjustable boost frequency dithering to reduce EMI combination of PWM and analog dimming. • Advanced control allows minimum PWM on-time down Switching frequency can be either above or below the AM to 0.3 µs, and avoids MLCC audible noises band, set by either a resistor or the synchronization pin to • LED contrast ratio: 15,000:1 at 200 Hz using PWM between 200 kHz and 2.3 MHz. A programmable dithering dimming alone, 150,000:1 when combining PWM and feature further reduces EMI. The Clock-Out pin allows other analog dimming converters to be fed the clock frequency, including programmed Continued on next page... dithering—even when the LED output is turned off.
PACKAGE:
The A80603 provides protection against application faults and external component open/short. Current sense/gate drive
24-Pin 4 mm × 4 mm QFN
functions allow optional use of an input supply disconnect FET
with Wettable Flank
in case of output to ground short fault in boost configuration. The A80603-1 is identical to the A80603 except for soft start timer Not to scale and FAULT pin behavior (see Fault Table section for details). VIN *optional VOUT R L1 SC D1 Q1 Cin RADJ ROVP C C GATE SW OUT1 OUT2 OVP Vsense Vin Vc CVDD PGND VDD RPU LED1 FAULT
A80603
LED2 Enable EN Up to 11 WLEDs in series LED3 Up to 120 mA/channel PWM PWM tON ≥ 0.3 µs APWM LED4 CLKOUT COMP AGND ISET FSET DITH PEB APWM 100 kHz 0-90% RZ CP R RDITH ISET RFSET C RPEB DITH CZ
Figure 1: Typical application diagram showing A80603 in Boost mode
A80603-DS March 4, 2019 MCO-0000619 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