Analog Devices Inc. DC1124A

Overview

DC1124A from Analog Devices (formerly Linear Technology) is a demonstration circuit board featuring the LT3591 step-up LED driver IC in a 3mm×2mm DFN package. It delivers 20mA constant current to drive up to ten white LEDs in series from a 3V–9V input, integrates a Schottky diode and open-circuit protection, and supports PWM and DC dimming via the CTRL pin.

For engineers reviewing the DC1124A datasheet, DC1124A pinout, DC1124A application, or DC1124A equivalent, this page provides verified board-level specifications, functional context, dimming implementation options, efficiency at 78.2% (3.6V/10LED), and alternative evaluation platforms for high-brightness LED lighting designs.

Technical Context

The DC1124A implements the LT3591 - a fixed-frequency (0.75–1.2MHz), current-mode boost converter optimized for LED driving. Its high-side current sensing enables ground-referenced LED cathodes, eliminating the need for a dedicated return path. The integrated Schottky diode and open-circuit protection (40–44V CAP pin clamp) reduce external component count and improve reliability.

Input voltage is constrained to 3–9V by onboard capacitors (LT3591 absolute max is 12V). Dimming is supported via three methods: filtered PWM (C4/R3), direct DC control, or direct PWM (with Q1 installed and C4/R3 removed), all routed through the CTRL terminal.

Key Specifications

Availability

DC1124A is available at Aetrix Electronics and suitable for LED backlighting, portable display illumination, automotive interior lighting, and industrial status indicator designs requiring stable component supply and validated reference performance.

Supply support for DC1124A 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 acquired Linear Technology in 2017; LTC remains a flagship analog/power product line known for high-performance DC/DC converters, LED drivers, and precision power management ICs.

The DC1124A belongs to Linear's demonstration circuit series for LED drivers, designed to accelerate prototyping of efficient, compact, and dimmable high-brightness LED systems using integrated boost controllers.

FAQ

What is the primary function of the DC1124A demonstration board?

The DC1124A demonstration board is a fully assembled and tested platform for evaluating the LT3591 LED driver IC. It implements a fixed-frequency, current-mode boost converter that delivers 20mA to drive up to ten white LEDs in series from a 3V–9V input. The DC1124A includes integrated Schottky diode, open-circuit protection, and multiple dimming interfaces - all pre-configured to validate real-world LED driving performance without custom layout.

Does the DC1124A support PWM dimming, and how is it implemented?

Yes, the DC1124A supports three dimming modes: filtered PWM (via C4/R3), direct DC control, and direct PWM (requiring removal of C4/R3 and installation of Q1). In direct PWM mode, the CTRL pin accepts a logic-level PWM signal to modulate LED brightness with minimal flicker. All implementations are documented in the Quick Start Guide and rely on the LT3591's internal current regulation loop - ensuring consistent performance across dimming methods on the DC1124A.

What is the maximum number of LEDs the DC1124A can drive, and what limits this capability?

The DC1124A can drive up to ten white LEDs in series, limited by the LT3591's output voltage headroom and the 40–44V open-circuit protection threshold on the CAP pin. At 20mA output current and typical forward voltage (~3.2V per white LED), ten LEDs require ~32V - well within the protection clamp. Exceeding ten LEDs risks triggering open-circuit protection or exceeding the LT3591's practical output compliance, making the DC1124A's design boundary precisely defined for 10-LED strings.

Is the DC1124A compatible with input voltages above 9V?

No - the DC1124A's input voltage range is strictly 3V–9V due to the rating of its onboard input capacitors. Although the LT3591 IC itself supports up to 12V absolute maximum input, the DC1124A board's passive components (especially C1/C2) are selected for 10V rating and thermal derating. Applying >9V risks capacitor overstress and premature failure. For higher-input applications, users must refer to the LT3591 datasheet and design a custom board - the DC1124A is not rated beyond 9V.

Where can I obtain design files for the DC1124A?

Design files for the DC1124A - including schematic, layout (Gerber), and bill of materials - are available directly from Analog Devices. The Quick Start Guide states: "Design files for this circuit board are available. Call the LTC factory." Customers should contact Analog Devices' technical support or visit analog.com/support to request the DC1124A design archive, which contains full engineering resources needed to replicate or modify the DC1124A functionality in custom designs.