Analog Devices Inc. DC903A-B

Overview

DC903A-B from Analog Devices (formerly Linear Technology) is a demonstration board for the LTC3240-3.3/LTC3240-2.5 step-up/step-down charge pump DC/DC converter IC. It supports fixed 3.3V or 2.5V output, operates from 1.8V–5.5V input, delivers up to 150mA, features automatic mode switching between LDO and charge pump operation, and includes thermal/short-circuit protection in a 6-lead 2mm × 2mm DFN package.

For engineers reviewing the DC903A-B datasheet, DC903A-B pinout, DC903A-B application, or DC903A-B equivalent, this board enables rapid evaluation of LTC3240-3.3/LTC3240-2.5 performance under real-world load transients, efficiency vs. input voltage, soft-start behavior, shutdown current (<1µA), and ripple characteristics - critical for low-power handheld and battery-operated designs.

Technical Context

The DC903A-B implements the LTC3240-3.3 or LTC3240-2.5 IC in a fully assembled, tested configuration with optimized layout: three 0603 ceramic capacitors (CIN = 1µF, CFLY = 1µF, COUT = 4.7µF), exposed-pad DFN soldering to ground plane, and test points for VIN, VOUT, SHDN, and flying capacitor nodes. It validates the IC's dual-mode operation - LDO mode when VIN ≥ VOUT + 100mV, and 1.2MHz constant-frequency charge pump mode when VIN drops below that threshold.

Board-level design incorporates thermal management per LTC3240 requirements: GND (Pin 1) and exposed pad (Pin 7) connected to internal/external ground planes, enabling θJA ≈ 80°C/W. The board supports both LTC3240-3.3 and LTC3240-2.5 variants via component selection, preserving identical footprint and interface logic (active-low SHDN, CMOS-compatible thresholds).

Key Specifications

Availability

DC903A-B is available at Aetrix Electronics and suitable for portable medical sensors, IoT edge nodes, camera modules, and industrial handheld terminals requiring stable component supply, fast prototyping validation, and production-ready layout reference.

Supply support for DC903A-B 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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, communications, and industrial markets.

The DC903A-B belongs to Linear Technology's DC/DC Demonstration Board family, designed to accelerate adoption of their high-efficiency, low-quiescent-current power converters - specifically targeting space-constrained, battery-powered applications where size, efficiency, and reliability are critical.

FAQ

What is the primary function of the DC903A-B evaluation board?

The DC903A-B evaluation board is a fully assembled hardware platform for evaluating the LTC3240-3.3 and LTC3240-2.5 step-up/step-down charge pump DC/DC converters. It provides immediate access to all critical signals (VIN, VOUT, SHDN, C+, C−), includes optimized passive components, and validates key performance metrics including efficiency, transient response, soft-start timing, and shutdown behavior - enabling engineers to verify DC903A-B functionality before integrating the LTC3240 into custom designs.

Does the DC903A-B support both LTC3240-3.3 and LTC3240-2.5 variants?

Yes, the DC903A-B supports both LTC3240-3.3 and LTC3240-2.5 variants through discrete component selection - specifically the output capacitor (COUT) and optional jumper configuration. The board's layout, thermal design, and signal routing are identical for both parts, allowing direct comparison of 3.3V and 2.5V output performance using the same DC903A-B hardware without PCB modification.

What external components are required to operate the DC903A-B?

No additional external components are required to operate the DC903A-B. It ships with all necessary passives pre-installed: 1µF input capacitor (CIN), 1µF flying capacitor (CFLY), and 4.7µF output capacitor (COUT), all in 0603 ceramic format. Users need only apply a DC input voltage (1.8V–5.5V) and optionally toggle the SHDN pin to enable/disable regulation - making DC903A-B ready for bench testing out-of-box.

How does the DC903A-B demonstrate the LTC3240's automatic mode switching?

The DC903A-B demonstrates automatic mode switching by allowing users to sweep the input voltage across the transition threshold (~VOUT ± 100mV). When VIN exceeds VOUT + 100mV, the LTC3240 operates as a low-dropout regulator (LDO); when VIN falls below VOUT + 100mV, it seamlessly switches to 1.2MHz charge pump mode. This behavior is observable on DC903A-B via oscilloscope measurements of VOUT stability, ripple amplitude, and switching node activity - confirming seamless handoff without output dropout or oscillation.

Is thermal management implemented on the DC903A-B board?

Yes, thermal management is fully implemented on the DC903A-B board per LTC3240 datasheet requirements. Both GND (Pin 1) and the exposed thermal pad (Pin 7) are soldered to an internal solid ground plane, achieving the specified θJA ≈ 80°C/W. This design allows sustained 150mA output at 3.3V without thermal shutdown under typical ambient conditions, and enables accurate junction temperature estimation using the DC903A-B's thermal derating curve - critical for validating long-term reliability in DC903A-B-based systems.