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Automotive Grade Multi-GNSS Dual-frequency High Precision RTK & INS Integrated Positioning Module

UM681A is a high precision dual-frequency GNSS & INS integrated navigation module developed by Unicore for the intelligent driving market. Based on the proprietary multi-system dual-frequency high -performance SoC - UC6580A, the module supports multi-system dual-frequency joint positioning or single system standalone positioning with centimeter-level accuracy.

Ordering Information

Supply at multiples of 250 pieces

vechicle gps


Product Characteristics

  • Supports concurrent operation of GPS, BDS, GLONASS and Galileo

  • Provides high precision positioning service via standard interface

  • Centimeter-level positioning accuracy & raw data output

  • GNSS chip qualified according to AEC-Q100 and 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.

Technical Specifications

Performance Specifications

Channel96 channels, based on UFirebirdII
FrequencyGPS L1C/A, L1C*, L5
BDS B1I, B1C*, B2a
Galileo E1, E5a
NavIC L5*
ModesSingle-system standalone positioning
Multi-system joint positioning
Time to First Fix (TTFF)Cold Start: < 26 s
Hot Start: < 2 s
Re-acquisition : < 2 s
DGPS (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)10.05 m/s (GNSS)
1PPS20 ns
Tracking-162 dBm
cold start-147 dBm
Hot Start-157 dBm
Reacquisition-158 dBm
Data Update Rate1 Hz / 5 Hz / 10 Hz
Differential DataRTCM V3.X
Data FormatNMEA 0183, Unicore

Physical Specifications

Dimensions22.0 x 17.0 x 2.6 mm
Package54 pin, LGA
Operating Temperature-40°C ~ +85 °C/105 °C
Storage Temperature-40°C ~ +85 °C/105 °C

Electrical Specifications

Voltage2.7 V ~ 3.6 V DC
LNA2.7 V ~ 3.3 V, < 100 mA
Power Consumption270 mW

Functional Ports

1 × I2C*
1 × SPI*

Functional Characteristics

Passive Antenna, Active Antenna, AGNSS *

NOTE: * Supported by specific firmware. 1 68% at 30 m/s for dynamic operation,open sky


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Product Data Sheet Request
Comprehensive product feature specifications.

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