Analog Devices Inc. DC843A

Overview

DC843A from Analog Devices (formerly Linear Technology) is a demonstration circuit for the LT3479 high-current boost LED driver IC, implementing a camera flash and torch solution with AOT3218 Flash LED. It delivers 700mA/300ms flash current or 150mA constant torch current from a 2.7V–4.5V Li-ion input, controlled by an on-board PIC microcontroller programmed with DC843A firmware.

For engineers reviewing the DC843A datasheet, DC843A pinout, DC843A application, or DC843A equivalent, key selection considerations include its integrated PIC-based state management, dual-mode (flash/torch) button interface, thermal-safe flash timing enforcement, low-power auto-shutdown behavior, and compatibility with LT3479 DFN layout requirements.

Technical Context

Demonstration circuit DC843A implements a complete, production-ready LED driver reference design centered on the LT3479 - a current-mode DC/DC boost converter with internal 2.5A NPN switch, fixed 1.2MHz switching frequency, and programmable flash/torch current via external resistors. The board integrates discrete power components including input capacitors, output capacitor, Schottky diode, and a small inductor to support compact camera module integration.

The on-board PIC microcontroller (not specified by part number in source, but confirmed as DC843A-programmed) manages user interaction via three tactile buttons (ON/OFF, TORCH, FLASH), enforces thermal safety by blocking repeated flash triggers during cooldown, controls LED state-indicator (red/green), and initiates automatic shutdown after ~10 seconds of inactivity to preserve battery life.

Key Specifications

Availability

DC843A is available at Aetrix Electronics and suitable for camera flash modules, smartphone auxiliary lighting systems, and industrial inspection torch applications requiring stable component supply and validated reference design implementation.

Supply support for DC843A includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (including legacy Linear Technology products) designs precision analog, mixed-signal, and power management ICs for industrial, automotive, communications, and consumer applications.

DC843A belongs to the Linear Technology Demonstration Circuit (DC) series - purpose-built evaluation platforms that validate real-world performance of key ICs like the LT3479 in application-specific configurations.

FAQ

What is the primary function of the DC843A demonstration circuit?

The DC843A demonstration circuit implements a fully functional high-current LED driver for camera flash and torch modes using the LT3479 boost controller and AOT3218 LED. Its primary function is to showcase validated layout, thermal management, and firmware-controlled operation - not to serve as a standalone production component. DC843A includes button-driven user interface, red/green status LED, and auto-shutdown logic implemented via its onboard PIC microcontroller programmed with DC843A software.

Does the DC843A include the LT3479 IC, and what package is used?

Yes, the DC843A includes the LT3479 IC assembled in a 10-lead (3mm × 3mm) low-profile DFN package, as confirmed in the Quick Start Guide. This package requires careful PCB layout per the LT3479 datasheet's "Layout Considerations" section to ensure thermal performance and stability. The DC843A board itself serves as the reference layout for that DFN footprint and thermal pad implementation.

How does the PIC microcontroller on DC843A affect system behavior?

The PIC microcontroller on DC843A - programmed with DC843A firmware - actively manages user inputs, enforces flash timing (300ms), prevents consecutive flashes during thermal recovery (indicated by red LED), toggles torch mode, and initiates low-power shutdown after ~10 seconds of inactivity. It is essential to DC843A's safe, intuitive operation and cannot be omitted or replaced without redesigning firmware and control logic.

Can the DC843A be used directly in production, or is it only for evaluation?

The DC843A is a demonstration circuit intended for evaluation and design reference - not certified for direct production use. While its layout and BOM are production-relevant, it lacks full qualification (e.g., extended temperature testing, long-term reliability validation). For production, designers should extract the validated schematic, layout guidelines, and thermal design from DC843A and implement them in their own qualified system-level board incorporating the LT3479 and AOT3218.

What documentation is required to properly use the DC843A?

To properly use the DC843A, engineers must consult three documents: the DC843A Quick Start Guide (this document), the LT3479 datasheet (for electrical specifications, timing diagrams, and layout rules), and the AOT3218 datasheet from Advanced Optoelectronic Technology (for LED thermal derating, pulse-width limits, and peak current ratings). All three are mandatory for safe, reliable operation - especially under flash conditions.