# HMC472A Digital RF Attenuator - Module Specifications

Extracted from Analog Devices HMC472A datasheet for the Amazon module variant.

---

## Electrical Specifications

**Test Conditions:** T_A = +25°C, Vdd = +5V, Vctl = 0/+5V (unless otherwise noted)

![Electrical Specifications Table](electrical-specifications.jpg)

| Parameter | Frequency | Min | Typ | Max | Units |
|-----------|-----------|-----|-----|-----|-------|
| **Insertion Loss** | DC - 1.5 GHz | — | 1.4 | 1.8 | dB |
| | 1.5 - 3.0 GHz | — | 1.7 | 2.3 | dB |
| | 3.0 - 3.8 GHz | — | 1.9 | 3.0 | dB |
| **Attenuation Range** | DC - 3.8 GHz | — | 31.5 | — | dB |
| **Return Loss** (RF1 & RF2, All States) | DC - 3.8 GHz | — | 20 | — | dB |

### Attenuation Accuracy

Referenced to insertion loss:

| Attenuation States | Frequency | Max Error |
|--------------------|-----------|-----------|
| All States | DC - 1.0 GHz | ±(0.20 + 3% of Setting) dB |
| 0.5 - 3.5 dB States | 1.0 - 2.2 GHz | ±(0.15 + 4% of Setting) dB |
| 4.0 - 31.5 dB States | 2.2 - 3.0 GHz | ±(0.30 + 3% of Setting) dB |
| All States | 3.0 - 3.8 GHz | ±(0.35 + 5% of Setting) dB |

### Power Handling & Linearity

| Parameter | Frequency | Value | Units |
|-----------|-----------|-------|-------|
| Input Power for 0.1 dB Compression | 0.1 - 3.8 GHz | 30 | dBm |
| **IIP3** (Two-Tone, 0 dBm each) | | | |
| — REF to 15.5 dB States | 0.1 - 3.8 GHz | 54 | dBm |
| — 16.0 to 31.5 dB States | 0.1 - 3.8 GHz | 49 | dBm |

### Switching Characteristics

| Parameter | Frequency | Typical | Units |
|-----------|-----------|---------|-------|
| t_RISE, t_FALL (10/90% RF) | DC - 3.8 GHz | 40 | ns |
| t_ON, t_OFF (50% CTL to 10/90% RF) | DC - 3.8 GHz | 60 | ns |

---

## Bias Voltage & Current

**Supply:** Vdd = +5V ± 10%

![Bias and Control Voltage Tables](bias-voltage-current-control-voltage-truth-table.jpg)

| Vdd (V) | Idd Typical (mA) |
|---------|------------------|
| +4.5 | 2.4 |
| +5.0 | 2.5 |
| +5.5 | 2.6 |

---

## Control Voltage States

| State | Bias Condition |
|-------|----------------|
| **Low** | 0 to +0.8 Vdc @ -5 µA Typ. |
| **High** | +2.0 to +5.0 Vdc @ 40 µA Typ. |

> **Note:** Vdd = +5V

---

## Truth Table

Each control pin (V1-V6) contributes a specific attenuation value when set **Low**:

| Pin | Attenuation Value |
|-----|-------------------|
| V1 | 16 dB |
| V2 | 8 dB |
| V3 | 4 dB |
| V4 | 2 dB |
| V5 | 1 dB |
| V6 | 0.5 dB |

### Example Attenuation States

| V1 (16dB) | V2 (8dB) | V3 (4dB) | V4 (2dB) | V5 (1dB) | V6 (0.5dB) | Total Attenuation |
|-----------|----------|----------|----------|----------|------------|-------------------|
| High | High | High | High | High | High | Reference (I.L.) |
| High | High | High | High | High | Low | 0.5 dB |
| High | High | High | High | Low | High | 1 dB |
| High | High | High | Low | High | High | 2 dB |
| High | High | Low | High | High | High | 4 dB |
| High | Low | High | High | High | High | 8 dB |
| Low | High | High | High | High | High | 16 dB |
| Low | Low | Low | Low | Low | Low | 31.5 dB |

> **Note:** Any combination of the above states will provide an attenuation approximately equal to the sum of the bits selected.

---

## Functional Diagram & Pinout

![Functional Diagram and Application Circuit](functional-diagram-application-circuit.jpg)

### Pin Assignment (24-Pin QFN, Top View)

| Pin | Function | Pin | Function |
|-----|----------|-----|----------|
| 1 | N/C | 13 | ACG7 |
| 2 | VDD | 14 | N/C |
| 3 | N/C | 15 | RF2 |
| 4 | RF1 | 16 | N/C |
| 5 | N/C | 17 | N/C |
| 6 | ACG1 | 18 | N/C |
| 7 | ACG2 | 19 | V1 (16 dB) |
| 8 | ACG3 | 20 | V2 (8 dB) |
| 9 | ACG4 | 21 | V3 (4 dB) |
| 10 | ACG5 | 22 | V4 (2 dB) |
| 11 | ACG6 | 23 | V5 (1 dB) |
| 12 | N/C | 24 | V6 (0.5 dB) |
| **Base** | **GND** | | |

---

## Application Circuit

### Recommended Component Values

| Reference | Value | Function |
|-----------|-------|----------|
| C1 | 1000 pF | VDD bypass capacitor |
| C2 | 1000 pF | RF1 DC blocking / coupling |
| C3 | 1000 pF | RF2 DC blocking / coupling |
| C4-C8 | 330 pF | ACG2-ACG6 bypass capacitors |
| C9 | 330 pF | ACG7 bypass capacitor |

### Circuit Notes

- **VDD** (pin 2) requires 1000 pF bypass to ground
- **RF1** (pin 4) and **RF2** (pin 15) use 1000 pF DC blocking capacitors for AC coupling
- **ACG pins** (ACG2-ACG6 on pins 7-11, ACG7 on pin 13) require 330 pF bypass capacitors to ground

> **Note:** For operations from 700 MHz to 2700 MHz, pins 6 through 13 (ACG1-ACG7) may be left unconnected.

---

## Performance Graphs

![Insertion Loss and Return Loss Graphs](insertion-and-return-loss-graphs.jpg)

### Insertion Loss vs Frequency

Two graphs showing insertion loss across temperature (+25°C, +85°C, -40°C):

1. **Low Frequency Range (DC - 350 MHz)**
   - Insertion loss approximately 1.0 to 1.2 dB
   - Minimal temperature variation

2. **Full Frequency Range (DC - 4 GHz)**
   - Insertion loss increases from ~1.2 dB at low frequencies to ~2.0 dB at 4 GHz
   - Temperature variation more pronounced at higher frequencies
   - -40°C shows best performance, +85°C shows highest loss

### Return Loss RF1 & RF2

Two graphs showing return loss for major attenuation states:

1. **Low Frequency Range (DC - 350 MHz)**
   - Return loss typically better than -15 dB across all states
   - Best performance around 100 MHz

2. **Full Frequency Range (DC - 4 GHz)**
   - Reference and low attenuation states (0.5-16 dB): -15 to -25 dB return loss
   - Maximum attenuation state (31.5 dB): return loss degrades above 2 GHz
   - All states maintain better than -10 dB return loss across band

---

## Quick Reference Summary

| Specification | Value |
|---------------|-------|
| Frequency Range | DC - 3.8 GHz |
| Attenuation Range | 0 - 31.5 dB |
| Step Size | 0.5 dB |
| Insertion Loss (typ) | 1.4 - 1.9 dB |
| Return Loss (typ) | 20 dB |
| IIP3 | 49 - 54 dBm |
| Supply Voltage | +5V ± 10% |
| Supply Current | 2.5 mA typ |
| Switching Speed | 40 - 60 ns |
| Package | 24-pin QFN |
| Input/Output Impedance | 50Ω |