ADRF5720 - 6-bit Attenuator 9kHz-40GHz | Analog Devices
MPN: ADRF5720 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $25 | $25.00 |
| 10 | $22.5 | $225.00 |
| 100 | $19.75 | $1,975.00 |
| 500 | $17.25 | $8,625.00 |
| 1,000 | $15.9 | $15,900.00 |
ADRF5720 Overview
A digital attenuator is a type of RF control component that reduces the amplitude of an RF signal by a controlled amount, set digitally via a parallel or serial interface. It belongs to the broader family of RF signal-conditioning components that includes switches, phase shifters, and variable gain amplifiers. Digital attenuators are essential in applications such as automatic gain control (AGC), signal leveling, calibration, and gain compensation in communication, radar, and test-and-measurement systems.
Key features of the ADRF5720 include its ultra-wideband frequency coverage from 9 kHz to 40 GHz, which is rare among digital attenuators, and its high attenuation accuracy. The device is pin-compatible with the ADRF5730, the fast switching version that operates from 100 MHz to 40 GHz. This allows designers to upgrade or downgrade between the two parts without PCB changes. The ADRF5720 also features a serial interface for setting attenuation, and it operates from a single 3.3 V or 5 V supply.
The ADRF5720 is fabricated using a silicon process, which provides high linearity and low power consumption. The device includes an on-chip driver and a serial-to-parallel interface, simplifying integration into digital control systems. The LGA package is designed for high-frequency performance, with low parasitic inductance and capacitance. The exposed pad provides a low thermal resistance path, enabling efficient heat dissipation at up to 500 mW RF power handling.
Typical applications for the ADRF5720 include AGC loops, signal leveling in test equipment, radar calibration, gain compensation in communication systems, and power control in satellite ground terminals. Its wide frequency range makes it suitable for both low-frequency baseband and high-frequency microwave applications up to 40 GHz, including 5G mmWave bands. The device is also commonly used in RF front-end protection and broadband transceiver power leveling.
When designing with the ADRF5720, it is important to provide adequate grounding and decoupling. The RF input and output ports should be matched to 50 Ω, and the control lines should be properly terminated to avoid spurious responses. The device's serial interface should be programmed according to the datasheet timing requirements to ensure accurate attenuation settings.
Drop-in alternatives for ADRF5720 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADRF5720 (same form factor and footprint) — differing in Control Interface, Insertion Loss, Package, Pin Compatibility, Attenuation Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADRF5730
✅ Drop-In✓ In Stock
$29 / Unit
View Datasheet →ADRF5721
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.1 / Unit
View Datasheet →ADRF5731
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ADRF5720 Specifications (manufacturer-published)
| Product Type | Silicon 6-Bit Digital Attenuator |
| Attenuation Range | 31.5 dB |
| Step Size | 0.5 dB |
| Frequency Range | 9 kHz to 40 GHz |
| Insertion Loss | Better than 4.5 dB |
| Characteristic Impedance | 50 Ω |
| Power Handling | 500 mW |
| Package | 24-Terminal 4 mm × 4 mm LGA (VFLGA Exposed Pad) |
| Operating Temperature | -40°C to +105°C |
| RoHS | Compliant |
| Supply Voltage | 3.3 V or 5 V |
| Control Interface | Serial Interface |
| Pin Compatibility | Pin-compatible with ADRF5730 |
| Mounting Type | Surface Mount |
ADRF5720 Interfaces & Connectors
ADRF5720 exposes the following interfaces and connectors as published by the manufacturer: Power Input. Expansion header pinout, connector pin numbering, and electrical limits are defined in the manufacturer documentation.
| Power Input | 3.3 V or 5 V |
Refer to the manufacturer documentation for the full expansion header pinout and connector pin numbering.
Power & Thermal Characteristics
| Operating Temperature | -40°C to +105°C |
| Power Input | 3.3 V or 5 V |
Power input and thermal parameters for ADRF5720 as published by the manufacturer.
Typical Applications
ADRF5720 is suitable for 6 applications: Automatic Gain Control (AGC), Test and Measurement Instrumentation, Radar Calibration, Satellite Communications, Wideband RF Front-End Protection and Power Leveling, 5G and 6G Communication Transceivers.
Automatic Gain Control (AGC)
The ADRF5720's 31.5 dB range with 0.5 dB steps provides precise closed-loop gain control across 9 kHz to 40 GHz. AGC loops can update attenuation rapidly via the serial interface to maintain a constant output level as input signals vary by more than 30 dB. The wideband coverage handles both baseband and microwave carriers, while the 50 Ω matched ports simplify cascading with amplifiers and mixers. In receiver front ends, the inherent low insertion loss (<4.5 dB) preserves noise figure. The main trade-off is that attenuation accuracy degrades near the millimeter-wave band, so calibration at operating frequency is recommended.
Recommended
Test and Measurement Instrumentation
In signal generators, spectrum analyzers, and bench test sets, the ADRF5720 provides accurate leveling across a remarkably wide frequency range. The 0.5 dB step size enables repeatable calibration steps, and the 500 mW power handling supports moderate RF input levels without external pads. The RF ports are matched to 50 Ω, which is the standard impedance for coaxial test systems, allowing direct insertion into the signal chain. Its compact 4 mm × 4 mm LGA package fits dense instrument designs, and the serial interface allows automated calibration routines.
Recommended
Radar Calibration
Radar systems require precise signal leveling to maintain stable receiver sensitivity. The ADRF5720 operates from 9 kHz to 40 GHz, covering L, S, C, X, Ku, and Ka bands used in defense and weather radar. Its 0.5 dB step and fast serial programming make it suitable for calibration between pulses. The exposed pad LGA enables efficient heat transfer under high duty-cycle operation. In phased-array radar, multiple ADRF5720s can be arrayed for per-element gain adjustment, and their pin compatibility with ADRF5730 allows designers to trade switching speed for low-frequency coverage.
Recommended
Satellite Communications
Satellite ground terminals need automatic power control to counter rain fade and spacecraft EIRP variations. The ADRF5720's 6-bit, 0.5 dB step control provides up to 31.5 dB of gain adjustment across C, Ku, and Ka uplink/downlink bands. The serial interface simplifies FPGA integration, and the RoHS-compliant, 4 mm × 4 mm LGA package withstands the -40°C to +105°C temperature range often found in outdoor ODU electronics. With better than 4.5 dB insertion loss, it has minimal impact on the noise budget in the receive path.
Recommended
Wideband RF Front-End Protection and Power Leveling
Before high-dynamic-range ADCs or sensitive LNAs, the ADRF5720 can be used to protect the input from overdriven signals while maintaining a constant level to the converter. Its 9 kHz to 40 GHz range covers many IF and RF architectures. The 50 Ω matched ports reduce reflections, and the series-attenuator topology with shunt resistive network allows absorption of excess power. The device's inline configuration does not require an external driver, and the serial control word can be updated on-the-fly to adjust system gain.
Recommended
5G and 6G Communication Transceivers
In 5G and emerging 6G transceivers, wideband attenuators are used for TX power control and RX gain flattening. The ADRF5720 operates up to 40 GHz, covering mmWave bands such as n257, n258, and n260. The serial interface and standard 3.3 V or 5 V supply simplify integration with baseband processors and RF front-end modules. Its 0.5 dB step size enables precise beamform calibration and temperature compensation, while the small LGA package saves board area in compact phased-array modules.
Recommended
Recommended Products Summary
Engineering reference data for ADRF5720 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADRF5730 | ADRF5721 | ADRF5731 |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 24-Terminal LGA 4x4 mm | 24-Terminal LGA 4x4 mm (same) | 24-Terminal LGA 4x4 mm (same) | 24-Terminal LGA 4x4 mm (same) |
| Step Size | 0.5 dB | 0.5 dB | 0.5 dB | 0.5 dB |
| Switching Speed | Standard | Fast | Standard | Fast |
Key Differentiators
- Lowest starting frequency in the pin-compatible family (vs ADRF5730)
- Standard switching speed balanced with wideband coverage (vs ADRF5731)
- Mature, fully documented ecosystem (vs ADRF5721)
Design Notes
For operation up to 40 GHz, match all RF transmission lines to 50 Ω using coplanar waveguide or grounded microstrip on a high-frequency laminate. Place ground vias adjacent to the RF pins to minimize parasitic inductance. Keep the RF traces as short and straight as possible, avoiding right-angle bends that cause reflections at millimeter-wave frequencies.
The exposed pad of the ADRF5720 LGA package serves as both ground and heat path. For continuous 500 mW RF power dissipation, solder the pad to a solid ground plane with thermal vias to lower thermal resistance. The device is rated from -40°C to +105°C; ensure the junction temperature stays within limit under worst-case enclosure temperatures.
Decouple the 3.3 V or 5 V supply with a 100 nF capacitor close to the digital supply pin and a larger 1 uF bulk capacitor. Terminate the serial control lines properly and follow the timing requirements in the datasheet. Do not apply RF power beyond the 500 mW rating, as this can damage the internal resistive network. For frequencies near 40 GHz, account for connector and trace loss when calibrating attenuation accuracy.
Compliance Information
RoHS compliant per Analog Devices product page and datasheet. AEC-Q100 not applicable for this RF attenuator. REACH, halogen-free, and conflict-minerals status not explicitly stated in verified web data; RoHS compliance implies lead-free.
