MAX2769ETI+T Review | GNSS Receiver Performance and Selection Guide

Summary: This article reviews the MAX2769ETI+T from Analog Devices. It covers supported constellations and bands, sensitivity, phase noise, power and low-power tips, test methods, PCB layout tips, and comparisons with related parts. Key numbers come from the official datasheet and eval board tests.

Official datasheet (PDF): MAX2769 Datasheet (Analog Devices). The part data also appears on distributor pages.

MAX2769ETI+T

Part number: MAX2769ETI+T

Manufacturer: Analog Devices (formerly Maxim Integrated)

Role: Single-chip GNSS RF front end (LNA, mixer, filters, PGA, PLL, ADC)

Product overview

The MAX2769 is a highly integrated GNSS receiver chip. It puts most RF front-end and sampling functions on one chip. The package is a 28-pin QFN 5×5 mm. The chip supports GPS L1, GLONASS G1, and Galileo E1. The datasheet shows a cascaded noise figure near 1.4 dB. The total gain can reach about 110 dB, depending on gain settings. These points help the chip receive weak signals.

Key specs at a glance

These specs come from the official datasheet and distributor pages. Use the datasheet for final design choices.

Sensitivity and real receive performance

Low noise figure and high gain set receiver sensitivity. Datasheet and eval notes show end-to-end capture sensitivity near -139 dBm and tracking sensitivity near -152 dBm. These numbers depend on receiver algorithms and ADC bit width. They mean the chip can still get a position in weak urban or indoor conditions.

Phase noise and positioning accuracy

Phase noise affects carrier-phase accuracy and high-precision fixes like RTK. The MAX2769 uses a fractional-N PLL and works with standard crystals. The PLL design keeps phase noise low on L1. Low phase noise improves phase observations and reduces loop jitter. For very high-precision tasks, use an external reference or a higher-grade clock to raise stability further.

Power and low-power strategies

The chip draws tens of milliamps in full operation. Typical active current is about 25 mA. The device has a low-power mode at about 10 mA. It also has an idle mode near 0.5 mA. To save battery, use low-power mode between fixes and wake for fixes only. Also enable high-gain paths only when needed. Eval kit examples show power sequencing and mode switching to lower average power.

Test methods and measurement examples 

Use repeatable steps to judge real performance:

1. Test environment: use a shielded room or shield box to cut outside interference, or use a GNSS signal simulator.
2. Antenna and feed: use a known gain active antenna or RF attenuators to simulate different RSL levels.
3. Sensitivity test: lower simulator output and record the weakest power that allows acquisition or stable tracking.
4. Phase noise test: use a spectrum analyzer or phase noise tester to measure VCO/PLL phase noise and compare crystals.
5. Power test: measure average current in real workflows (cold start, hot start, continuous tracking) to judge power strategy.

The official eval kit and app notes give wiring and software samples to build a test bench.

Comparison with similar parts 

Nearby parts include the MAX2769C and later multi-band receivers like MAX2771. The MAX2769C adds BeiDou B1 support, so it covers more regions and constellations. Power and noise specs are similar. Choose the part that matches band needs and any industrial or automotive requirements.

PCB layout and practical design tips

Layout affects real sensitivity and interference immunity. Key tips:

• Keep antenna input traces short and 50Ω and avoid sharp bends.
• Place decoupling capacitors close to supply pins and keep a solid ground plane.
• Use thermal vias under the exposed pad and connect to inner copper for heat spread.
• If using an active antenna, route ANTBIAS with filter and current limit.
• In high interference setups, add an external SAW or bandpass filter before the LNA. A small insertion loss filter raises system NF only slightly and improves interference rejection.

Pros and cons 

Pros: Highly integrated so BOM and board area drop. Low noise figure and high gain give good sensitivity. Built-in IF filters and fractional-N PLL make design simpler.

Cons: You must do careful PCB layout to get best results. Power draw is normal for GNSS but not ideal for ultra low-power tiny trackers unless you duty cycle. If you need more bands, pick MAX2769C or other multi-band chips.

Conclusion

If you need a small and sensitive GNSS front end that supports multi-constellation L1/E1, the MAX2769ETI+T is a solid choice. It gives stable reception in weak signal areas and it reduces external parts. Pay attention to antenna, filtering, and PCB layout, and pick power modes that match battery life and response time requirements. If you need wider band coverage or automotive features, consider the MAX2769C or newer multi-band parts.

FAQ

What is the MAX2769ETI+T?

It is an integrated GNSS RF front end for GPS/GLONASS/Galileo L1/E1 signals.

What are its key electrical numbers?

Supply 2.7–3.3 V, typical active current ~25 mA, cascaded noise figure ~1.4 dB, total gain up to ~110 dB.

What applications suit this chip?

Handheld navigation, automotive navigation, UAV positioning, wearable trackers, and IoT location devices where board area is limited and sensitivity matters.

References

Analog Devices — MAX2769 Datasheet (PDF): https://www.analog.com/media/en/technical-documentation/data-sheets/max2769.pdf.

Distributor pages and EV kit documentation on Mouser, Digi-Key, and the Analog Devices product and eval pages.

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