User manual for the Techtotop D303-3 high‑precision GNSS navigation module, covering features, interfaces, specifications and usage guidelines.
The D303-3 is a compact, 24‑pin navigation module that supports BDS B1, GPS L1 and GLONASS L1 frequencies. It integrates a high‑precision SOC baseband, RF front‑end, power‑management and LNA+SAW, providing high sensitivity and low power consumption for vehicle, marine and handheld positioning applications.
The manual details the module’s hardware interfaces (power, antenna, reset, 1PPS, UART), software protocol, mechanical dimensions, electrical characteristics, recommended PCB design, and ordering information. Safety notes include static protection and proper soldering procedures. This manual is written in Chinese.
| Positioning accuracy (open sky, horizontal) | <10 cm |
|---|---|
| Positioning accuracy (open sky, altitude) | <15 cm |
| Speed measurement accuracy | <0.1 m/s |
| First‑fix time (cold start) | <28 s |
| Acquisition sensitivity | -147 dBm |
| Tracking sensitivity | -163 dBm |
| UART baud rate range | 4800–230400 bps (default 9600 bps) |
| Data update rate | 1 Hz |
| Operating voltage (VCC) | 3.3 V |
| Backup voltage (V_BCKP) | 3.3 V |
| Average power consumption | 25 mA |
| Standby power consumption | 20 µA |
| Operating temperature range | -40 °C to 85 °C |
| Storage temperature range | -40 °C to 125 °C |
| Package type | 24‑pin stamp hole (24pin邮票孔封装) |
The default UART baud rate is 9600 bps.
It supports BDS B1, GPS L1 and GLONASS L1 frequencies.
The module provides three power input pins (VCC, V_BCKP, V_ANT) and one power output pin (VCC_RF).
The antenna supply voltage (V_ANT) should be set according to the active antenna specifications, typically up to 3.3 V.