UM681 is a high-precision GNSS + IMU integrated positioning and navigation module developed by Unicore for industrial applications. The module is based on the proprietary multi-system, dual-frequency, high-performance GNSS SoC - UC6580I, and is equipped with a 6-axis IMU. It can achieve centimeter-level positioning and can maintain continuous positioning in environments without satellite signals, such as tunnels and underground garages.
Ordering Information
Supply at multiples of 250 pieces
Supports concurrent operation of GPS, BDS, GLONASS and Galileo (L1 + L5)
Provides high-precision positioning service via standard interface
Centimeter-level positioning accuracy & raw data output
Production process conforms to IATF16949
Built-in MEMS, output of integrated navigation results with a single module, continuous positioning even in tunnels and underground parking lots.
| Channel | 96 channels, based on UFirebird II |
| Frequency | GPS L1C/A, L1C*, L5 |
| BDS B1I, B1C*, B2a | |
| GLONASS G1* | |
| Galileo E1, E5a | |
| NavIC L5* | |
| QZSS L1, L5 | |
| SBAS L1C/A | |
| Modes | Single-system standalone positioning |
| Multi-system joint positioning | |
| Time to First Fix (TTFF) | Cold Start: < 26 s |
| Hot Start: < 2 s | |
| Re-acquisition : < 2 s | |
| Single Point Positioning (RMS) | Horizontal: 1.5 m (open sky) |
| Vertical: 2.5 m (open sky) | |
| RTK (RMS) | Horizontal: 1 cm + 1 ppm (open sky) |
| Vertical: 2 cm + 1 ppm (open sky) | |
| Positioning error of INS only | < 1% of the driving distance without GNSS signals |
| Velocity Accuracy(RMS)2 | 0.05 m/s(open sky) |
| 1PPS | 20 ns |
| Sensitivity | GNSS |
| Tracking: -162 dBm | |
| cold Start: -147 dBm | |
| Hot Start: -157 dBm | |
| Reacquisition:-158 dBm | |
| Data Update Rate | 1 Hz / 5 Hz / 10 Hz |
| Differential Data | RTCM V3.X |
| Data Format | NMEA 0183, Unicore |
| Dimensions | 22.0 x 17.0 x 2.6 mm |
| Package | 54 pin, LGA |
| Operating Temperature | -40°C ~ +85 °C/105 °C |
| Storage Temperature | -40°C ~ +85 °C/105 °C |
| Voltage | 2.7 V ~ 3.6 V DC |
| LNA | 2.7 V ~ 3.3 V, < 100 mA |
| Power Consumption1 | 240 mW |
| 2 × UART*(LVTTL) | |
| 1 × I2C* | |
| 1 × SPI* | |
| 1 × 1PPS(LVTTL) |
| Passive Antenna, Active Antenna, AGNSS * |
NOTE: * Supported by specific firmware.
1 Open sky, continuous tracking
2 68% at 30 m/s for dynamic operation,open sky