Qorvo CMD245C4: Datasheet & RF Specifications

The Qorvo CMD245C4 is a broadband 6–18GHz GaAs MMIC low phase noise amplifier designed for demanding microwave applications, including radar, satellite communications and RF test equipment. It combines low additive phase noise, 18dB typical gain at 10GHz and 50-ohm matched RF ports in a compact 4 × 4mm ceramic QFN package.

At 10GHz, the CMD245C4 provides a typical noise figure of 4.5dB, saturated output power of +21dBm and additive phase noise of -165dBc/Hz at a 10kHz offset.

This guide reviews the CMD245C4 datasheet, RF performance across the C, X and Ku bands, pinout, positive bias requirements, PCB integration, applications and purchasing considerations.

1. Qorvo CMD245C4 Overview

The CMD245C4 is a low phase noise amplifier based on GaAs MMIC technology. Its primary design advantage is broadband RF amplification with low additional phase noise.

Unlike high-power GaN amplifiers intended to deliver tens of watts of RF output power, the CMD245C4 is intended for signal amplification where gain, phase noise, linearity and power consumption are important.

Key Features

• Frequency range: 6GHz to 18GHz.

• Small-signal gain: 18dB typical at 10GHz.

• Low additive phase noise: -165dBc/Hz at 10kHz offset under specified test conditions.

• Noise figure: 4.5dB typical at 10GHz.

• 50-ohm matched RF input and output.

• Positive drain and gate supply voltages.

• Compact 4 × 4mm leadless ceramic QFN package.

• Pb-free and RoHS compliant.

2. CMD245C4 Datasheet Specifications

The following information is based on Qorvo's CMD245C4 Datasheet Rev. A, dated April 29, 2022.

Note: Values are typical unless otherwise identified. RF performance varies with frequency, bias and temperature. Refer to the manufacturer's electrical specification tables and performance plots for design limits.

3. RF Performance: 6–12GHz vs 12–18GHz

Although the CMD245C4 covers 6–18GHz, engineers should evaluate the electrical characteristics separately across the lower and upper portions of the band.

Test conditions: VDD = 5V, VGG = 3V and ambient temperature = 25°C.

The comparison shows that typical gain and output compression performance decrease toward the higher-frequency band, while the specified typical noise figure increases.

For applications operating near 18GHz, designers should pay particular attention to the reduced P1dB and the increased noise figure.

4. CMD245C4 Low Phase Noise Performance

Low additive phase noise is a key characteristic of the CMD245C4.

The manufacturer specifies typical phase noise of -165dBc/Hz at a 10kHz offset under its measurement conditions.

What Is Additive Phase Noise?

When a signal passes through an amplifier, the amplifier can introduce additional noise and fluctuations that affect the phase of the output signal.

In frequency-sensitive systems, this may influence spectral purity, measurement accuracy and system-level signal quality.

Low additive phase noise is especially relevant in microwave signal chains where spectral purity is important.

Why Is Phase Noise Important in Radar?

Radar systems often use highly stable oscillators and frequency-conversion stages. Excessive phase noise can degrade the ability to distinguish weak signals near strong signals and may affect overall radar performance.

The CMD245C4 can be considered in signal paths requiring low additional phase noise, provided that its gain, noise figure and output-power characteristics meet the complete system requirements.

Important distinction: Additive phase noise and noise figure describe different amplifier characteristics. A low phase noise specification does not automatically mean the amplifier has the lowest available noise figure.

5. Noise Figure and Gain Considerations

At 10GHz, the CMD245C4 offers 18dB typical gain and 4.5dB typical noise figure.

For a receiver front end, noise figure is an important parameter because it affects the overall receiver noise performance.

Is CMD245C4 a Low Noise Amplifier?

Qorvo describes the device as a low phase noise amplifier rather than positioning it primarily as an ultra-low noise front-end amplifier.

Although it provides useful RF gain, its noise figure may be higher than that of specialized ultra-low-noise amplifiers designed for weak-signal receiver inputs.

For a first-stage receiver amplifier, engineers should evaluate the complete cascaded noise figure using the Friis noise formula.

For a frequency-generation or low-phase-noise distribution chain, additive phase noise may be a more significant selection parameter.

6. Output Power: P1dB vs Saturated Power

The CMD245C4 has a typical output P1dB of 18dBm and saturated output power of 21dBm at 10GHz.

The 18dBm P1dB corresponds to approximately 63mW, while 21dBm saturated output power corresponds to approximately 126mW.

What Does P1dB Mean?

The 1dB compression point indicates the power level at which amplifier gain has decreased by 1dB relative to its small-signal response.

For systems requiring low distortion, designers generally operate below the compression region, with an appropriate output-power back-off.

CMD245C4 Is Not a High-Power PA

The CMD245C4 should not be selected as a direct substitute for multi-watt GaN power amplifiers.

It is better suited for broadband low phase noise amplification, selected driver applications and microwave signal conditioning where its output-power capability is sufficient.

7. CMD245C4 Pinout and Pin Functions

The CMD245C4 is supplied in a 24-pin 4 × 4mm ceramic QFN package with an exposed ground paddle.

The primary signal and power connections are:

Refer to the Qorvo package and pin diagrams for exact pad orientation and recommended PCB footprint.

In particular, the RF input is DC coupled, while the RF output is internally DC blocked. This distinction should be considered when connecting adjacent RF stages.

8. CMD245C4 Biasing Requirements

The CMD245C4 uses positive drain and positive gate voltages, which can simplify the power-supply architecture compared with amplifiers requiring negative gate bias.

Recommended Operating Conditions

Recommended Power-On Sequence

According to the Qorvo datasheet:

1. Apply drain voltage VDD and set it to +5V.

2. Apply gate voltage VGG and set it to +3V.

Recommended Power-Off Sequence

1. Turn off gate voltage VGG.

2. Turn off drain voltage VDD.

Important: Follow the device-specific biasing sequence. Do not assume that the negative-gate-bias sequencing used for some GaAs power amplifiers applies to the CMD245C4.

Provide the recommended decoupling and bypass capacitors at VDD and VGG according to the manufacturer application circuit.

9. PCB Layout and Thermal Design

The CMD245C4 uses a leadless 4 × 4mm ceramic surface-mount package, making PCB layout and assembly important for repeatable RF performance.

RF Transmission Lines

Use controlled-impedance 50-ohm RF transmission lines at the input and output.

Keep the RF traces short and minimize discontinuities caused by pad geometry, trace transitions and nearby components.

Grounding and Via Design

The exposed ground paddle should be connected to the PCB ground system according to Qorvo's land-pattern guidance.

Use sufficient ground vias to provide a low-inductance RF return path and an appropriate thermal conduction path.

Supply Decoupling

Install the recommended bypass capacitors close to the power-supply connections.

The evaluation-board bill of materials includes 0.33μF, 1000pF and 100pF capacitors. Refer to the manufacturer's complete application circuit for component locations and connections.

Thermal Considerations

The device has a specified junction-to-case thermal resistance of 108°C/W and a maximum channel temperature rating of 150°C.

Its operating ambient temperature range is -40°C to +85°C.

Designers must evaluate actual temperature rise and ensure that absolute maximum ratings are not exceeded.

For package layout and assembly, refer to Qorvo Application Notes AN102 and AN105.

10. CMD245C4 Applications

10.1 X-Band Radar Systems

The CMD245C4 covers the X-band frequency range and provides low additive phase noise, making it a candidate for selected radar signal-chain applications.

10.2 C-Band and Ku-Band Microwave Systems

Its 6–18GHz coverage enables use in a variety of microwave communication and signal-conditioning circuits.

Engineers should verify the gain, noise figure and compression characteristics at their exact operating frequencies.

10.3 Satellite Communications

Satellite communication equipment may require low phase noise amplification for stable signal generation and distribution.

The CMD245C4 can be evaluated in suitable signal paths where its RF specifications and power limits meet the system design.

10.4 RF Test and Measurement

Microwave test equipment, laboratory signal chains and RF evaluation systems may benefit from the amplifier's bandwidth and low additive phase noise characteristics.

Careful PCB layout, biasing and impedance control are necessary to achieve repeatable measurement results.

11. CMD245C4 vs CMD245: What's the Difference?

Qorvo offers CMD245 and CMD245C4 as related low phase noise amplifier products.

The CMD245C4 offers a packaged SMT solution, while CMD245 is supplied as a bare die.

Although they share a similar frequency range and amplifier concept, their assembly requirements and performance specifications differ.

Replacement note: CMD245 and CMD245C4 are not mechanically interchangeable. Always compare the exact datasheets and application requirements.

12. CMD245C4 Datasheet Download

For detailed RF performance plots, pinout, absolute maximum ratings, recommended PCB layout and application circuits, refer to the official Qorvo documentation.

• Qorvo CMD245C4 Official Product Page

• CMD245C4 Datasheet Rev. A – April 29, 2022 (PDF)

• Qorvo CMD245 Bare-Die Amplifier

Verify the latest datasheet revision and product status with Qorvo before releasing a production design.

13. Qorvo CMD245C4 Price, Availability & RFQ

Are you sourcing the Qorvo CMD245C4 6–18GHz Low Phase Noise Amplifier for a prototype, RF system upgrade or production project?

DataStorageIC can assist with part-number sourcing inquiries, quotation requests and availability checks for Qorvo RF and microwave components.

Please provide the following information:

• Manufacturer: Qorvo

• Part Number: CMD245C4

• Required quantity

• Target price, if available

• Requested delivery date

• Destination country or region

• Required documentation or packaging information

• Application and frequency requirements, if technical support is needed

Price, inventory and lead time are subject to confirmation at the time of inquiry.

Request CMD245C4 Pricing and Availability: Visit DataStorageIC and submit your requirements through the website inquiry form.

14. Related RF & Microwave Components

For more information on microwave amplifier selection and sourcing, explore the following resources:

• RF & Microwave Components – Browse RF amplifier, connector and microwave component categories.

• DataStorageIC Electronic Components – Submit RF component sourcing and BOM quotation inquiries.

Conclusion

The Qorvo CMD245C4 is a 6–18GHz GaAs MMIC low phase noise amplifier combining 18dB typical gain at 10GHz, low additive phase noise and a compact 4 × 4mm ceramic QFN package.

Its positive bias configuration and 50-ohm matched RF ports help simplify integration into suitable microwave systems.

When selecting this amplifier, engineers should consider phase noise, frequency-dependent noise figure, output compression, PCB layout and thermal performance rather than relying only on nominal gain.

For CMD245C4 datasheets, specifications, pricing and availability inquiries, contact DataStorageIC with your required quantity and application details.