# 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.