Broadcom launches its lowest power GNSS receiver for mobile, wearables

The BCM4778’s third-generation dual-frequency GNSS receiver features advanced multipath mitigation, L5 acquisition capability, LTE filtering and jamming protection

Broadcom Inc. has launched the BCM4778, its lowest power L1/L5 GNSS receiver chip optimized for mobile and wearable applications. Equipped with the latest GNSS innovations, the third-generation chip is 35% smaller and consumes five times less power than the previous generation.

Broadcom will be presenting further information on the chip in the Session B5, Panel: GNSS Chipset Technology – Trends, Opportunities and Challenges panel at the ION GNSS+ 2021 on Sept. 24.

Dual-frequency GNSS continues to be an important location feature for modern mobile and wearable devices, providing greater positioning accuracy for location-based applications. The advanced L5 signal enables sidewalk-level accuracy for pedestrian navigation in urban environments, as well as lane-level accuracy for vehicle navigation.

Reduction in GNSS power consumption is crucial to extending the battery life of a mobile or wearable device. Compared to GNSS receivers used in integrated platforms, Broadcom’s single-chip BCM4778 delivers significantly lower power consumption and higher performance while offering more advanced GNSS features, such as the next-generation Grid Tracking urban multipath mitigation technology.

“We are excited to see this impressive power reduction, combined with the L5 Grid Tracking technology in the new Broadcom GNSS chip. This will increase the impact of Google’s 3DMA ray-tracing for urban multipath mitigation,” said Frank van Diggelen, principal software engineer at Google.

Longer battery life. The BCM4778 increases the GNSS always-on battery life on a smartwatch by 30 hours compared to the previous generation chip operating on a 300-mAh battery. The extended battery life helps drive new experiences in smartwatches and phones, including keeping the GNSS always-on for fitness applications for multiple days on a single battery charge.

In addition, the BCM4778 features fully integrated LNAs for L1 and L5 bands, which reduces RF front-end BOM costs and footprint requirements, suitable for space-constrained applications. The chip offers increased flexibility to smartwatch and phone designers with its small size. Having the ability to place the BCM4778 closer to the antenna helps improve signal reception and enhances overall GNSS performance.

The BCM4778 dual-frequency chip is designed for small mobile and wearables. (Photo: Broadcom)

Product Highlights

• 7nm CMOS technology
• Typical power consumption
• 4mW L1 band only
• 6mW L1+L5 simultaneous
• FCBGA package
• New Grid Tracking technology
• Advanced multipath mitigation
• Continuously tracks the full L5 channel
• Capable of L5 acquisition
• Increased processing capability and throughput
• Advanced LTE filtering and jamming mitigation
• Enhanced LTE Band 13 and Band 14 filtering
• Spoofing and jamming detector
• Jamming mitigation through multiband and multi constellation
• Reduced BOM cost and footprint
• Flexibility in using internal LNAs
• Optional operation without interstage SAW filters
• Integrated switching regulator with direct connect to battery

“With the launch of this third generation dual-frequency GNSS receiver chip, Broadcom continues the tradition of raising the bar for mobile GNSS,” said Vijay Nagarajan, vice president of marketing for the Wireless Communications and Connectivity Division at Broadcom. “Always-on dual frequency GNSS is a key request from mobile and wearable OEMs, and we are thrilled to deliver it.”

“Consumer electronic companies have been faced with the challenge of managing power consumption versus performance, often having to choose one over the other. Broadcom’s innovative approach to the BCM4778 allows their customers to realize improvements on both fronts,” said Ramon T. Llamas, research director for mobile devices at IDC. “The result: device manufacturers can enable new experiences and run applications over a sustained period of time. In addition, by reducing its BOM cost and its physical footprint, Broadcom is enabling further benefits from cost savings and design configurability.”

Broadcom is currently sampling the BCM4778 to its early access partners and customers. Please contact your local Broadcom sales representative for samples and pricing.