Realtek RTL8771B

General Description

The RTL8771BW and RTL8771BF are high-performance GNSS single chips that support a multi-standard (GPS/ BeiDou/GLONASS) positioning solution. The RTL8771B(W/F) includes on chip RF, baseband, and RISC CPU. The RTL8771B(W/F) achieves high-performance low-SNR tracking/acquisition sensitivity, and fast Time-to-First-Fix (TTFF). The RTL8771B(W/F) supports up to 210 PRN channels, including 22 simultaneous tracking channels.

The RTL8771B(W/F) also provides various navigation applications including SBAS/DGPS (WAAS, MSAS, EGNOS, GAGAN, etc.) and AGPS, which speed the positioning time. An always-on backed-up memory and a real time clock are provided to accelerate acquisition at system restart up.

Featuring an on-chip integrated LNA, the RTL8771B(W/F) delivers a total receiver noise figure of 2.6 dB (before ADC). The RTL8771B(W/F) has on-chip regulators that are easily integrated into your system without requiring an extra voltage regulator. The crystal support feature allows users to implement low-cost design circuits with minimum BOM cost.

With an embedded 32-bits RISC controller running at 87/43.5MHz, the system performs time-critical processes, including data decoding and positioning. The real-time operating system also allows for efficient task scheduling.

The RTL8771B(W/F) offers an RS-232 data port and I2C interface for data exchange. The configurable RS-232 interface enables use of a higher data rate to send more data, as well as National Marine Electronics Association (NMEA) packets. Standard pre-defined HCI commands make the RTL8771B(W/F) easy and flexible to configure.

A time mark PPS pulse is generated by the RTL8771B(W/F), which is synchronized with GPS time. A General-purpose IO configured as Position-Fixed indicator allows customers to implement system functions. The general-purpose IO with power-on trap functions allows for easier system configuration.