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+# HMC472 Based RF Attenuator
+
+## Overview
+6-bit digital RF attenuator module based on the Analog Devices HMC472A GaAs MMIC. 0.5 dB steps, 0–31.5 dB range, DC–3.8 GHz. Single +5V supply, SMA connectors, 50Ω impedance. Manual control via 6-position pin header (active-low TTL/CMOS).
+
+## External Links
+- [Manufacturer Page](https://www.analog.com/en/products/hmc472a.html)
+- [Datasheet (PDF)](https://www.analog.com/media/en/technical-documentation/data-sheets/hmc472a.pdf)
+- [Amazon Listing](https://www.amazon.com/Digital-Attenuator-DC-3-8GHz-Parallel-Attenuation/dp/B0828GQ672)
+
+## Local Resources
+
+### Datasheet (`datasheet/`)
+- `hmc472a.pdf` — Full Analog Devices datasheet (8 pages)
+- `hmc472a.md` — Extracted markdown version with all specs, tables, pin descriptions, and application notes
+- `page_001.png` through `page_008.png` — Individual page images
+- `vectors/` — SVG extractions from each datasheet page
+  - `hmc472a_page_N.svg` — Full page vector renders (pages 1–8)
+  - `hmc472a_page_N_drawings.svg` — Isolated drawings/diagrams only (pages 1–8)
+
+### Module Documentation (`docs/`)
+- `module-specs.md` — Consolidated module specs: electrical specs, truth table, pin assignments, application circuit, performance graphs
+- `electrical-specifications.jpg` — Electrical specs table from datasheet
+- `bias-voltage-current-control-voltage-truth-table.jpg` — Bias/control voltage and truth table
+- `functional-diagram-application-circuit.jpg` — Block diagram and recommended application circuit
+- `insertion-and-return-loss-graphs.jpg` — Performance graphs across frequency/temperature
+
+### Product Photos (`marketing/`)
+- Front and back board photos showing HMC472A IC, SMA connectors, 6-pin header, and passive components
+
+## Key Specs (Quick Reference)
+
+| Parameter | Value |
+|-----------|-------|
+| Frequency Range | DC – 3.8 GHz |
+| Attenuation | 0 – 31.5 dB (0.5 dB steps) |
+| Insertion Loss | 1.4 – 1.9 dB typ |
+| Step Error | ± 0.25 dB typ |
+| IIP3 | +49 to +54 dBm |
+| Supply | +5V, 2.5 mA typ |
+| Max Input Power | +20 dBm (module) / +28 dBm (IC abs max) |
+| Switching | 40–60 ns |
+| Control | 6 pins, active-low (Low = attenuate) |
+
+## Truth Table (Control Pins)
+
+| Pin | Attenuation (when Low) |
+|-----|------------------------|
+| V1 | 16 dB |
+| V2 | 8 dB |
+| V3 | 4 dB |
+| V4 | 2 dB |
+| V5 | 1 dB |
+| V6 | 0.5 dB |
+
+All High = reference (insertion loss only). All Low = 31.5 dB. Any combination sums.
+