Datasheet ALT80800 (Allegro)
| Fabricante | Allegro |
| Descripción | Automotive-Grade, Constant-Current 2.0 A PWM Dimmable Synchronous Buck LED Driver |
| Páginas / Página | 23 / 1 — ALT80800. Automotive-Grade, Constant-Current 2.0 A. PWM Dimmable … |
| Formato / tamaño de archivo | PDF / 2.2 Mb |
| Idioma del documento | Inglés |
ALT80800. Automotive-Grade, Constant-Current 2.0 A. PWM Dimmable Synchronous Buck LED Driver. FEATURES AND BENEFITS
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ALT80800 Automotive-Grade, Constant-Current 2.0 A PWM Dimmable Synchronous Buck LED Driver FEATURES AND BENEFITS DESCRIPTION
• AEC-Q100 qualified The ALT80800 is a synchronous buck switching regulator • Supply voltage 4.5 to 55 V that provides constant-current output to drive high-power • 2.0 A maximum output over operating temperature range LEDs. It integrates both high-side and low-side N-channel • Integrated high-side and low-side MOSFETs: DMOS switches for DC-to-DC step-down conversion. A true 200 mΩ / 150 mΩTYP average current is output using a cycle-by-cycle, controlled • True average output current control on-time method. • Internal control loop compensation Output current is user-selectable by an external current sense • Integrated 5 V, 14 mA LDO regulator for peripheral circuits resistor. Output voltage is automatically adjusted to drive • Dimming via PWM pin or EN pin down to 0.1% at 200 Hz various numbers of LEDs in a single string. This ensures the • Analog dimming (ADIM pin) for brightness calibration optimal system efficiency. and thermal foldback • Low-power shutdown (1 µA typical) LED dimming is accomplished by a direct logic input pulse- • Cycle-by-cycle current limit width modulation (PWM) signal at the PWM pin while EN is • Active low fault flag output enabled. Alternatively, applying a PWM signal at the EN pin • LED open fault mask setting for low VIN operation while PWM pin is high can enable “chopped battery” PWM • Undervoltage lockout (UVLO) and thermal shutdown dimming for legacy control modules. protection Furthermore, an Analog Dimming input (ADIM pin) can be • Switching frequency dithering for improved EMC used, for example, to calibrate the LED current or implement • Robust protection against: thermal foldback in conjunction with external NTC thermistor. □ Adjacent pin-to-pin short □ Pin-to-ground short The ALT80800 is provided in a 16-pin TSSOP (suffix LP), □ Component open/short faults with exposed pad for enhanced thermal dissipation.
PACKAGE: APPLICATIONS:
16-Pin eTSSOP (suffix LP) Automotive lighting • Daytime running lights • Front and rear fog lights • Turn/stop lights • Map light Not to scale • Dimmable interior lights VIN C
ALT80800
IN VIN SW CBOOT L1 R GND SENSE EN BOOT LED+ VCCIN CSH TON External PWM CSL dimming signal PWM RON PWM V C CC LED External analog ADIM dimming signal FFn ADIM GND FFn VCC VCC VIN CBIAS SGND FDSET PGND GND
Figure 1: ALT80800 Typical Application Circuit
ALT80800-DS, Rev. 4 November 29, 2021 MCO-0000344 Document Outline Features and Benefits Description Applications Package Typical Application Circuit Selection Guide Specifications Absolute Maximum Ratings Thermal Characteristics Pinout Diagrams and Terminal List Tables Functional Block Diagrams Electrical Characteristics Functional Description Application Circuit Diagrams
• AEC-Q100 qualified The ALT80800 is a synchronous buck switching regulator • Supply voltage 4.5 to 55 V that provides constant-current output to drive high-power • 2.0 A maximum output over operating temperature range LEDs. It integrates both high-side and low-side N-channel • Integrated high-side and low-side MOSFETs: DMOS switches for DC-to-DC step-down conversion. A true 200 mΩ / 150 mΩTYP average current is output using a cycle-by-cycle, controlled • True average output current control on-time method. • Internal control loop compensation Output current is user-selectable by an external current sense • Integrated 5 V, 14 mA LDO regulator for peripheral circuits resistor. Output voltage is automatically adjusted to drive • Dimming via PWM pin or EN pin down to 0.1% at 200 Hz various numbers of LEDs in a single string. This ensures the • Analog dimming (ADIM pin) for brightness calibration optimal system efficiency. and thermal foldback • Low-power shutdown (1 µA typical) LED dimming is accomplished by a direct logic input pulse- • Cycle-by-cycle current limit width modulation (PWM) signal at the PWM pin while EN is • Active low fault flag output enabled. Alternatively, applying a PWM signal at the EN pin • LED open fault mask setting for low VIN operation while PWM pin is high can enable “chopped battery” PWM • Undervoltage lockout (UVLO) and thermal shutdown dimming for legacy control modules. protection Furthermore, an Analog Dimming input (ADIM pin) can be • Switching frequency dithering for improved EMC used, for example, to calibrate the LED current or implement • Robust protection against: thermal foldback in conjunction with external NTC thermistor. □ Adjacent pin-to-pin short □ Pin-to-ground short The ALT80800 is provided in a 16-pin TSSOP (suffix LP), □ Component open/short faults with exposed pad for enhanced thermal dissipation.
PACKAGE: APPLICATIONS:
16-Pin eTSSOP (suffix LP) Automotive lighting • Daytime running lights • Front and rear fog lights • Turn/stop lights • Map light Not to scale • Dimmable interior lights VIN C
ALT80800
IN VIN SW CBOOT L1 R GND SENSE EN BOOT LED+ VCCIN CSH TON External PWM CSL dimming signal PWM RON PWM V C CC LED External analog ADIM dimming signal FFn ADIM GND FFn VCC VCC VIN CBIAS SGND FDSET PGND GND
Figure 1: ALT80800 Typical Application Circuit
ALT80800-DS, Rev. 4 November 29, 2021 MCO-0000344 Document Outline Features and Benefits Description Applications Package Typical Application Circuit Selection Guide Specifications Absolute Maximum Ratings Thermal Characteristics Pinout Diagrams and Terminal List Tables Functional Block Diagrams Electrical Characteristics Functional Description Application Circuit Diagrams