Datasheet ALT80600 (Allegro)

ALT80600 LED Driver with Pre-Emptive Boost for Ultra-High Dimming Ratio and Low Output Ripple FEATURES AND BENEFITS DESCRIPTION
• Automotive AEC-Q100 qualified The ALT80600 is a multi-output LED driver for small-size • Wide input voltage range of 4.5 to 40 V for start/stop, LCD backlighting. It integrates a current-mode boost converter cold crank, and load dump requirements with internal power switch and four current sinks. The boost • Fully integrated LED current sinks and boost converter converter can drive up to 44 white LEDs, 11 LED per string, with internal power MOSFET at 120 mA (VF = 3.3 V max). LED sinks can be paralleled • Operate in Boost or SEPIC mode for flexible output together to achieve higher currents up to 480 mA. • Drives up to 11 series white LED in 4 parallel strings, at The ALT80600 operates from single power supply from 4.5 to up to 120 mA per string (VF = 3.3 V max). 40 V; once started, it can continue to operate down to 3.9 V. • Programmable boost switching frequency or sync This allows the part to withstand stop/start, cold crank, and externally from 200 kHz to 2.3 MHz load dump conditions encountered in automotive systems. • Clock-Out feature for internal switching frequency • Adjustable boost frequency dithering to reduce EMI The ALT80600 can control LED brightness through external • Advanced control allows minimum PWM on-time down PWM signal. By using the patented ‘Pre-emptive Boost’ to 0.3 µs, and avoids MLCC audible noises control, an LED brightness contrast ratio of 15,000:1 can be • LED contrast ratio: 15,000:1 at 200 Hz using PWM achieved using PWM dimming at 200 Hz. A higher ratio of dimming alone, 150,000:1 when combining PWM and 150,000:1 is possible when using a combination of PWM and analog dimming analog dimming. Continued on next page... Continued on next page...
PACKAGE: APPLICATIONS 24-Pin 4 mm × 4 mm QFN
• Automotive infotainment backlighting
with Wettable Flank
• Automotive cluster • Automotive center stack Not to scale • Automotive exterior lighting VIN = 4.5 to 40 V *optional VOUT ≤ 40 V 0.024 Ω 10 µH Q1 Cin 383 Ω 187 kΩ GATE SW OVP 4.7 µF 4.7 µF Vsense Vin Vc PGND 1 µF VDD 10 kΩ LED1 FAULT
ALT80600
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% 845 Ω 8.25 kΩ 100 pF 10 kΩ 40.2 kΩ 9.09 kΩ 68 nF 10 nF
Figure 1: Typical application diagram showing ALT80600 in Boost mode
ALT80600-DS, Rev. 2 March 13, 2019 MCO-0000393 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 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 Appendix A: Design Example