CML Micro CMX918 Low Power Software Defined Radio Tuner
CML Micro CMX918 Low Power Software Defined Radio (SDR) Tuner is a highly flexible RF front‑end processor optimized for compact, low‑power software‑defined radio (SDR) receivers. Covering an extensive frequency range from LF to VHF Band II, the CMX918 supports a wide variety of analog and digital communication systems. The device offers general‑coverage reception from 150kHz to 108MHz, with frequency‑tuned front‑end inputs and a fully configurable receive chain featuring variable gain, adjustable IF bandwidths, and programmable IF center frequencies. This high level of configurability enables precise adaptation to diverse air interfaces and challenging RF conditions, while keeping external component requirements minimal. The CML Micro CMX918 also includes support for ferrite‑rod antennas in LF and MF bands.
Designed for robust performance in real‑world environments, the CMX918 delivers a digital output ready for downstream processing by a DSP or FPGA, enabling software‑based demodulation, protocol decoding, and audio handling. This architecture is well-suited for SDR applications, supporting modes such as AM, FM, DRM/DRM+, SSB, NAVDAT, and other protocol‑specific waveforms entirely in software. The result is a compact, versatile, energy‑efficient receiver architecture that enables long battery life at low cost.
Built‑in programmable power management allows unused circuit blocks to be powered down to minimize current consumption. Device control and configuration are handled through a serial interface selectable between industry‑standard I2C or SPI/C‑BUS. Operating from a single 2.9V to 3.6V supply, the CMX918 is offered in a 32‑pin VQFN package with a central ground pad for optimal thermal and RF performance.
Features
- Low-power multi-mode SDR tuner
- 150kHz to 108MHz tuning range
- LF/MF/HF/VHF band optimized RF inputs
- High spurious-free dynamic range tuner
- Analog and digital modulation support
- Software configurable autonomous AGC
- Integrated VCO with low phase noise and fast lock
- Low-IF architecture
- Selectable optimized IF bandwidths
- Standard digital interfaces (SPI, I2C, I2S)
- 5mm x 5mm VQFN32 package for low-cost PCB design
- 2.9V to 3.6V supply
Applications
- Battery-powered SDR receivers
- IF processors for professional receivers
- Smartphone accessories
- In-car entertainment
Specifications
- 3.6V maximum analog supply, 2.9V typical
- 3.6V maximum I/O supply, 1.6V typical
- 30µA typical power down mode (powersave)
- HF band
- 2.0MHz to 40MHz input frequency range
- 50Ω typical input impedance
- 116dB typical input signal dynamic range
- LF band
- 150kHz to 280kHz input frequency range
- >1kΩ typical input impedance
- 107dB typical input signal dynamic range
- MF band
- 400kHz to 2000kHz input frequency range
- >1kΩ typical input impedance
- 107dB typical input signal dynamic range
- VHF band
- 40MHz to 108MHz input frequency range
- 50Ω typical input impedance
- 110dB typical input signal dynamic range
- 1820mW maximum allowable power dissipation at +25°C
- 18.2mW/°C maximum de-rating
- -40°C to +90°C maximum operating temperature range
Block Diagram
Recommended External Components
