Analog Devices Inc. DC391A-B

Overview

DC391A-B is a demonstration board from Analog Devices (formerly Linear Technology) designed to evaluate the LTC5505-2 RF power detector IC, operating across 300MHz–2700MHz with 18dBm max RF input and 2.7V–6V supply voltage. It provides buffered DC output voltage proportional to RF input power, with shutdown control via pin 3 and SMA RF input interface.

For engineers reviewing the DC391A-B datasheet, DC391A-B pinout, DC391A-B application, or DC391A-B equivalent, this board supports rapid characterization of RF power detection linearity, enable/shutdown timing, and input tuning techniques using accessible test points E1–E4, J1, and SW1.

Technical Context

The DC391A-B implements the LTC5505-2 IC in a fixed evaluation configuration: RF signal enters via SMA connector J1, couples through DC-blocking capacitor C1 to pin 1 (RF), and produces a temperature-stable DC output at pin 4 (Vout), accessible at test point E2. The SHDN pin (pin 3) is routed to E4 for external TTL-compatible enable/disable control.

Board-level design includes optional solder pads for input matching networks (R1/C5), a 22kΩ pull-up on SHDN (via SW1), and provision for 50Ω termination at E4 to measure shutdown-to-enable transition timing - supporting both static DC characterization and dynamic response analysis.

Key Specifications

Availability

DC391A-B is available at Aetrix Electronics and suitable for RF front-end validation, cellular infrastructure receiver calibration, and IoT transmitter power monitoring requiring stable component supply and documented reference performance.

Supply support for DC391A-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. (including legacy Linear Technology products) designs high-performance analog, mixed-signal, and RF ICs for precision signal chain and power management applications.

The DC391A-B belongs to Analog Devices' LTC demo board family, engineered specifically to accelerate evaluation of RF power detectors like the LTC5505 series in real-world impedance-matched environments.

FAQ

What is the primary function of the DC391A-B demo board?

The DC391A-B demo board is a dedicated evaluation platform for the LTC5505-2 RF power detector IC. It enables engineers to measure DC output voltage versus RF input power across 300MHz–2700MHz, verify shutdown timing, and assess input matching options. All critical signals - RF input (J1), supply (E1/E3), output (E2), and SHDN (E4) - are brought out to standard test points for immediate bench use. The DC391A-B does not operate as a standalone product but serves exclusively as an evaluation tool for the LTC5505-2.

Does DC391A-B support both LTC5505-1 and LTC5505-2 variants?

No - DC391A-B is configured specifically for the LTC5505-2. The original DC391A-A variant evaluates the LTC5505-1. While both ICs share identical pinout and core architecture, their internal scaling factors differ: LTC5505-2 delivers higher output voltage per dBm input. The DC391A-B board layout, component selection (e.g., no R1/C5 installed), and documented test procedures are validated only for LTC5505-2 operation.

How is shutdown functionality implemented on DC391A-B?

Shutdown on DC391A-B is controlled via the SHDN pin (pin 3) of the LTC5505-2, accessible at test point E4. A slide switch (SW1) provides manual enable/disable: grounding E4 forces shutdown; connecting E4 to VCC through a 22kΩ resistor enables operation. For dynamic testing, a pulse generator can drive E4 directly with 50Ω termination to ground - allowing precise measurement of enable/disable transition times. This implementation matches the LTC5505-2's specified TTL-compatible shutdown threshold.

What RF input interface does DC391A-B use, and is external attenuation required?

DC391A-B uses a standard SMA female connector (J1) for RF input, directly coupled to the LTC5505-2 RF input pin via DC-blocking capacitor C1. Although not mandatory, a 3dB attenuator pad between the signal generator and J1 is recommended to reduce impedance mismatch reflections and improve measurement repeatability - consistent with best practices cited in the DC391A Quick Start Guide and LTC5505-2 datasheet.

Can DC391A-B be used for production-level RF power measurement?

No - DC391A-B is strictly an evaluation board, not a production-grade instrument. Its layout lacks calibrated trace losses, temperature compensation, or long-term stability certification. While it accurately demonstrates LTC5505-2 behavior under lab conditions, production deployment requires integration of the LTC5505-2 IC into a custom PCB with controlled impedance, proper decoupling, and system-level calibration. The DC391A-B serves only to validate functionality, not to replace metrology-grade measurement equipment.