UNICORECOMM UM4B0 User manual

Unicore Confidential
WWW.UNICORECOMM.COM
INSTALLATION AND OPERATION
USER MANUAL
Data subject to change without notice.
Communications, Inc. Copyright© 2009-2021, Unicore
RTK Positioning Module
All-constellation All-frequency
GPS/BDS/GLONASS/Galileo
U M4B0

i
Revision History
Version
Revision History
Date
Ver. 1.0
First Edition
Feb. 2017
R3.1
Add the related description to clarify the VCC restrictions
2019-08-22
R3.2
Chapter 2.2: add the working current info of No.17 pin
2019-09-18
R3.3
2.5 Physical Specifications: update the weight value from
8.8 to 9.2
1.1 Overview: update the product diagram
2020-02-26
R3.4
Add QZSS
2020-07-01
R3.5
Fix typo/update BDS frequencies
2020-10-21
R3.6
Update dimensions
2020-10-28
R3.7
Add external antenna feed reference circuit
2020-12-17
R3.8
Update COFIG command
2021-01-22
R4
Remove information on the MEMS device and add RF
input power consumption of antennas
2021-04-13
R4.1
Add average current in chapter 2.4
2021-06-23
R4.2
Modify pin19 in Figure 2-2
2021-07-01
Disclaimer
Information in this document is subject to change without notice and does not
represent a commitment on the part of Unicore Communications, Inc. No part of this
manual may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying and recording, for any purpose without the
express written permission of a duly authorized representative of Unicore
Communications, Inc. The information contained within this manual is believed to be
true and correct at the time of publication.
© Copyright 2009-2021 Unicore Communications, Inc. All rights RSV.

UM4B0 User Manual
ii
Foreword
This <User Manual> offers you information in the features of the hardware, the
installation, specification and use of UNICORECOMM UM4B0 product.
This manual is a generic version. Please refer to the appropriate part of the manual
according to your purchased product configuration, concerning CORS, RTK and Heading.
Readers it applies to
This <User Manual> is applied to the technicists who know GNSS Receiver to some
extent but not to the general readers.

i
Contents
1INTRODUCTION .........................................1
1.1 OVERVIEW ..................................................................................................................................1
1.2 KEY FEATURES..............................................................................................................................1
1.3 TECHNICAL SPECIFICATIONS ............................................................................................................2
1.4 INTERFACES .................................................................................................................................2
2HARDWARE .............................................3
2.1 DIMENSIONS................................................................................................................................3
2.2 PIN DEFINITION (TOP VIEW)...........................................................................................................4
2.3 ELECTRICAL SPECIFICATIONS............................................................................................................6
2.4 OPERATIONAL CONDITIONS ............................................................................................................7
2.5 PHYSICAL SPECIFICATIONS ..............................................................................................................7
3HARDWARE DESIGN ......................................8
3.1 DESIGN IN CONSIDERATIONS...........................................................................................................8
3.2 UM4B0 REFERENCE DESIGN..........................................................................................................9
3.3 PINS.........................................................................................................................................10
3.4 PCB PACKAGING ........................................................................................................................11
3.5 RESET SIGNAL ............................................................................................................................12
3.6 ANTENNA..................................................................................................................................12
3.7 EXTERNAL ANTENNA FEED DESIGN.................................................................................................12
4INSTALLATION AND CONFIGURATION.......................14
4.1 ESD HANDLING PRECAUTIONS ......................................................................................................14
4.2 HARDWARE INSTALLATION............................................................................................................14
4.3 START UP..................................................................................................................................17
4.4 CONFIGURATION AND OUTPUT......................................................................................................17
4.4.1 Operation Procedures ........................................................................................................18
5CONFIGURATION COMMANDS...............................19
5.1 RTK REFERENCE STATION CONFIGURATION .....................................................................................20
5.2 RTK ROVER CONFIGURATION........................................................................................................21
5.3 MOVING BASE CONFIGURATIONS ..................................................................................................21
5.4 HEADING CONFIGURATION ...........................................................................................................21
6ANTENNA DETECTION ...................................22
7FIRMWARE UPGRADE ....................................22
8PRODUCTION REQUIREMENT...............................24
9PACKAGING ...........................................25

1
1Introduction
1.1 Overview
UM4B0 is a high precision positioning and heading RTK module developed by
Unicore Communications, targeting light robots, UAVs, intelligent vehicles, GIS
information collection, etc.
By employing a single UC4C0 (432 channel tracking) baseband chip and a single RF
chip, using single-sided SMD packaging, UM4B0 has achieved the smallest size
(30x40mm) in this industry with high accuracy heading and positioning output. It can
simultaneously track BDS B1I/B2I/B3I/B1C/B2a + GPS L1/L2/L5 + GLONASS
L1/L2+Galileo E1/E5a/E5b.
Figure 1-1 UM4B0 Module
1.2 Key Features
•30*40mm, the smallest multi-system multi-frequency high precision module
•Support GPS L1/L2/L5+GLONASS L1/L2+BDS B1I/B2I/B3I/B1C/B2a+Galileo
E1/E5a/E5b
•Based on 432 channel NebulasII GNSS SoC
•20Hz update rate
•Instant RTK initialization and long-distance RTK
•Enhanced multi-system multi-frequency RTK technology, JamShield adaptive
narrow-band anti-interference and U-AutoAlign multi-path mitigation
•Support odometer input and external high-performance IMU interface*
•SMD packaging

UM4B0 User Manual
2
1.3 Technical Specifications
Table 1-1 Performance Specifications
Channels
432 channels, based on
NebulasII SoC
RTK Initialization Time
<5s (typical)
Frequency
GPS L1/L2/L5
BDS B1I/B2I/B3I/B1C/B2a
GLONASS L1/L2
Galileo E1/E5a/E5b
Qzss L1/L2/L5
Initialization
Reliability
>99.9%
Single Point
Positioning
Horizontal: 1.5m
Cold Start
<25s
Vertical: 2.5m
Reacquisition
<1s
DGPS(RMS)
Horizontal: 0.4m
Correction
RTCM 3.0/3.2/3.3
Vertical: 0.8m
RTK(RMS)
Horizontal: 1cm+1ppm
Data Output
NMEA-0183, Unicore
Binary
Vertical: 1.5cm+1ppm
Update Rate
20Hz
Heading Accuracy
(RMS)
0.2 degree@1 m baseline
Time Accuracy (RMS)
20ns
Velocity Accuracy
(RMS)
0.03m/s
Power Consumption
1.8W
Dimension
30×40×4 mm
Table 1-2 Functional Ports
3x UART, 1xI2C, 1x SPI (LV-TTL)
1x1PPS（LV-TTL）
1x Event input
1.4 Interfaces
RF in
RF
Fron
tend
SAW
Filter
Nebulas-II UART
SPI
GPS
BDS
GLO
GAL
SBAS
Interface Event
TCXO
I2C
ANT_PWR
PPS
Figure 1-2 Block Diagram

3
1. RF Part
The receiver gets filtered and enhanced GNSS signal from the antenna via a coaxial
cable. The RF part converts the RF input signals into the IF signal, and converts IF
analog signal into digital signals required for NebulasII (UC4C0) digital processing.
2. NebulasII SoC (UC4C0)
The UM4B0 incorporates the processing from the NebulasII (UC4C0),
UNICORECOMM’s new generation high precision GNSS SoC with 55nm low power
design, which supports up to 12 digital intermediate frequency or 8 analog
intermediate frequency signals and can track 12 navigation signals with 432 channels.
3. 1PPS
UM4B0 outputs 1 PPS with adjustable pulse width and polarity.
4. Event
UM4B0 provides 1 Event Mark Input with adjustable pulse width and polarity.
2Hardware
2.1 Dimensions
Table 2-1 Dimensions
Symbol
Min. (mm)
Typ. (mm)
Max. (mm)
A
38.00
40.00
40.50
B
29.80
30.00
30.2
C
3.80
—
4.00
D
1.57
1.58
1.59
E
1.26
1.27
1.28
Pin
1.07

UM4B0 User Manual
4
Figure 2-1 Mechanical Dimensions
2.2 Pin Definition (Top View)
Figure 2-2 UM4B0 Pin Diagram

5
Table 2-2 Pin Definition
No
Pin
I/O
Description
1
GND
-
Ground
2
ANT_IN
I
GNSS antenna signal input
3
GND
-
Ground
4
GND
-
Ground
5
ANT_PWR
I
GNSS antenna power supply
6
GND
-
Ground
7
ANT_NLOD
O
GNSS antenna open circuit indicator
1: normal
0: antenna is open circuit
8
ANT_FFLG
O
GNSS antenna short circuit indicator
1: normal
0: antenna is short circuit
9
GND
Power
DGND/GND
10
RSV
-
RSV
11
RSV
-
RSV
12
RSV
-
RSV
13
RSV
-
RSV
14
GND
-
Ground
15
SPEED
I
Odometer- pulse
16
FWR
I
Odometer- direction
17
V_BACKUP
I
When the main power supply of the module VCC is
cut off, V_BCKP supplies power to RTC and SRAM.
Level requirements: 2.0~ 3.6 V, and the working
current is about 10uA. Can be suspended without
using the hot start function.
18
GND
-
Ground
19
PVT STAT
O
PVT positioning indicator, active-high. The module
outputs high level when positioning is available and
outputs low level when no positioning is
proceeded.
20
GPIO2
I/O
Common IO
21
RSV
-
RSV
22
FRESET_N
I
Reset to factory default (clear all user settings),
LVTTL active-low, activate for longer than 5
seconds.
23
ERR_STAT
O
Abnormal indicator, active-high. When the RTK
solution is fixed, it outputs high level, otherwise
outputs low level when the module completes its
self-diagnosis.
24
RTK_STAT
O
RTK positioning indicator, active-high. When the
module’s self-diagnosis system fails, it outputs high
level; otherwise outputs low level when it’s in other
positioning states or no positioning is proceeded.
25
GND
-
Ground
26
SPI_MISO
I
SPI data input
27
SPI_MOSI
O
SPI data output

UM4B0 User Manual
6
No
Pin
I/O
Description
28
SPI_CLK
O
SPI clock
29
SPI_SS0
O
SPI chip select 0
30
SPI_SS1
O
SPI chip select 1
31
3.3V_VCC
Power
Power Supply (+3.3V)
32
3.3V_VCC
Power
Power Supply (+3.3V)
33
GND
-
Ground
34
GND
-
Ground
35
TXD1
I/O
COM 1 transmit
36
RXD1
I
COM 1 receive
37
TXD2
O
COM 2 transmit
38
RXD2
I
COM 2 receive
39
TXD3
O
COM 3 transmit
40
RXD3
I
COM 3 receive
41
I2C_SDA
I/O
I2C data
42
I2C_SCL
I/O
I2C clock
43
GND
-
Ground
44
PPS
O
Pulse per second
45
EVENT
I
Event Mark
46
RST_N
I
Fast reset, will not clear user configurations. Active
Low, > 5 ms
47
GND
-
Ground
48
RSV
-
RSV
49
RSV
-
RSV
50
RSV
-
RSV
51
RSV
-
RSV
52
GND
-
Ground
53
RSV
-
RSV
54
RSV
-
RSV
55
GND
-
Ground
56
RSV
I
RSV
57
GND
-
Ground
58
GND
-
Ground
59
RSV
I
RSV
60
GND
-
Ground
2.3 Electrical Specifications
Table 2-3 Absolute Maximum Ratings
Item
Pin
Min
Max
Unit
Power Supply (VCC)
Vcc
-0.3
3.6
V
Voltage Input
Vin
-0.3
VCC+0.2
V
LNA Input
ANT_PWR
-0.3
6
V
GNSS Antenna Signal Input
ANT_IN
-0.3
ANT_PWR
V
RF Input Power Consumption of Antenna
ANT_IN
input power
+15
dBm
VCC Ripple (Rated Max.)
Vrpp
0
50
mV
Voltage Input (pins other than RXD1,
RXD2, RXD3)
Vin
-0.3
3.6
V

7
Item
Pin
Min
Max
Unit
Maximum ESD stress
VESD(HBM)
±2000
V
2.4 Operational Conditions
Table 2-4 Operational Conditions
Item
Pin
Min
Typical
Max
Unit
Condition
Power Supply (VCC)
Vcc
3.2
3.3
3.6
V
Pulse current*
Iccp
8.8
A
Vcc = 3.3 V
LOW Level Input
Voltage
Vin_low_1
-0.3
VCC*0.3
V
High Level Input
Voltage
Vin_high_1
VCC*0.7
VCC+0.3
V
LOW Level Output
Voltage
Vout_low
0
0.45
V
Iout= 4 mA
High Level Output
Voltage
Vout_high
VCC-0.45
VCC
V
Iout =4 mA
Antenna Gain
Gant
20
30
36
dB
Noise Figure
Nftot
2.5
3
3.5
dB
LNA Input
ANT_PWR
3.3
5
5.5
V
< 100mA
Operating
Temperature
Topr
-40
85
°C
Power Consumption
P
1.5
1.8
2.0
W
Average Current
Iavg
0.545
A
NOTE: Since the product contains capacitors at the input, inrush current will occur
during power-on. Evaluate in the actual environment in order to check the effect of
the supply voltage drop due to the inrush current.
2.5 Physical Specifications
Table 2-5 Physical Specifications
Size
30×40×4 mm
Weight
9.2g
Temperature
Operating: -40℃~+85℃
Storage: -55℃~+95℃
Humidity
95% No condensation
Vibration
GJB150.16-2009, MIL-STD-810
Shock
GJB150.18-2009, MIL-STD-810

UM4B0 User Manual
8
3Hardware Design
3.1 Design in Considerations
To make UM4B0 work properly, you need to properly connect the following:
The module VCC power-on behavior is repeatable, the initial level is lower than
0.4V, and the undershoot and ringing should be guaranteed to be within 5% VCC
Provide stable power to the VCC pin
Connect all the GND pins to ground
Connect VBAT pin to a 3.0V power supply
Connect ANT_IN signal to the antenna, and ensure the 50-ohm impedance
matching
Connect ANT_PWR to +3.3~5.5 V voltage, then supply +3.3~5.5 V feed to the
antenna through ANT_IN
Ensure COM1 is connected to a PC or an external processor, and users can use
this serial port to receive position data. COM1 is also necessary for firmware
upgrades
Properly connect the module’s reset pin FRESET_N to ensure complete reset of
the module. It will restore the module to the manufacturing configuration.
When ANT_NLOD, ANT_FFLG and antenna detection indication signal are
connected, the IO without any pull-up/down of the client MCU terminal is
required at the input.
In order to obtain proper performance, special concerns should be paid during the
design:
Power supply: A table and low ripple power supply is necessary for good
performance. Make sure the peak-to-peak voltage ripple does not exceed
50mVpp. It is recommended to use a power chip with current output capacity
greater than 2A to power the board.
-Use LDO to ensure the purity of power supply
-Try to place LDO close to the module in layout
-Widen the tracks of power circuit or use copper pour surface to transmit
current
-Avoid walking through any high-power or high inductance devices such as a
magnetic coil

9
Interfaces: Ensure that the signals and baud rate of the main equipment match
those of the UM4B0 module
Antenna interface: Make sure the antenna impedance matches, and the cable is
short without any kinks, try to avoid all acute angles
Try to avoid designing in any circuits underneath UM4B0
This module is a temperature sensitive device, so dramatic changes in
temperature will result in reduced performance. Keep it away as far as possible
from any high-power high-temperature air and heating devices
3.2 UM4B0 Reference Design
Figure 3-1 Minimum Reference Design

UM4B0 User Manual
10
Figure 3-2 UM4B0 Reference Design
3.3 Pins
Table 3-1 Pin Notes
Pin Name
Pin
I/O
Description
Notes
Power
Supply
VCC
31, 32
Power
Voltage Supply
Stable, clean low ripple power
supply, peak ripple power lower
than 50mVpp is preferred
ANT_PWR
5
Power
Antenna
Power Supply
Voltage supply for
active antenna
GND
1, 3, 4,
6, 9, 14,
18, 25,
33, 34,
43, 47,
52, 55,
57, 58,
60
Power
Ground
Connect all the GND signals to
ground. Better to use copper
pour surface.
Antenna
ANT_IN
2
I
Satellite Signal
Input
50 Ωimpedance matching
UART
TXD1
35
O
COM1
Transmit Data
COM1 output, leave
unconnected if not used

11
Pin Name
Pin
I/O
Description
Notes
RXD1
36
I
COM1 Receive
Data
COM1 input, leave unconnected
if not used
TXD2
37
O
COM2
Transmit Data
COM2 output, leave
unconnected if not used
RXD2
38
I
COM2 Receive
Data
COM2 input, leave unconnected
if not used
TXD3
39
O
COM3
Transmit Data
COM3 output, leave
unconnected if not used
RXD3
40
I
COM3 Receive
Data
COM3 input, leave unconnected
if no use
System
FRESET_N
22
I
Hardware
Reset (low
effective)
Restore factory settings by
lowering FRESET_N for no less
than 5 seconds
PPS
44
O
PPS signal
PPS
EVENT
45
I
EVENT signal
Event
3.4 PCB Packaging
Figure 3-3 UM4B0 recommended PCB Packaging (unit: mil, in brackets: mm)

UM4B0 User Manual
12
3.5 Reset Signal
UM4B0 module can’t work properly unless it is correctly reset after power on. To
ensure effective reset, the reset pin (RST) and power supply pin (VCC) must meet the
following time sequence requirement. To reset UM4B0 during normal operation,
please pull RST pin to low level for more than 5ms.
VCC
RST
> 5ms
Figure 3-4 UM4B0 RST
3.6 Antenna
The module has the antenna input pin ANT_IN, which provides a +3.3V antenna feed.
When an active antenna of +3.3~5V is adopted, please make sure the 50 Ωantenna
impedance is matched.
ANT_IN UM4B0 Module
Figure 3-5 UM4B0 Active Antenna Connection
3.7 External Antenna Feed Design
UM4B0 feeds the antenna signals to the required circuits internally, but in order to
effectively prevent damage from lightning and surges, circuit protection should be
installed externally to protect the module.
High voltage and high-power protection chips should be used to feed the antenna
from the outside of the module. A gas discharge tube, varistor, TVS tube and other
high-power protective devices may also be used in the antenna circuit to effectively
improve the prevention against lightning stroke and surge.

13
UM4B0
ANT_IN
ANT_BIAS
ANT
ANT_PWR
GND
L1
C2
C1
Figure 3-6 UM4B0 External Antenna Feed Reference Circuit
Remarks:
a) L1, feed inductor, 68nH RF inductor in 0603 package is recommended;
b) C1, decoupling capacitor, it is recommended to connect two capacitors of 100nF/100pF
in parallel;
c) C2, DC blocking capacitor, recommended 100pF capacitor.

UM4B0 User Manual
14
4Installation and Configuration
4.1 ESD Handling Precautions
UM4B0 Module is an Electrostatic Sensitive Device (ESD) and special precautions
when handling are required.
Electrostatic discharge may cause damages to the device. All operations
mentioned in this chapter should be carried out on an antistatic workbench,
wearing an antistatic wrist strap and using a conductive foam pad. If an
antistatic workbench is not available, wear an antistatic wrist strap and connect
the other end to a metal frame to avoid the effects of static electricity.
Hold the edge of the module, not in direct contact with the components
Please check carefully whether the module has obviously loose or damaged
components.
Figure 4-1 Typical Installation of UM4B0
Please check the contents of the package carefully after receiving the package of
UM4B0.
UM4B0 EVK suite (or evaluation board)
User manual
UPrecise software
Qualified antenna
MMCX antenna cable
PC or Laptop with serial ports (Win7 or above), with UPrecise installed
4.2 Hardware Installation
After the above preparation, please follow the steps below to install:
Step 1: Make sure to take all the anti-static measures, such as wearing an anti-
static wrist strap, grounding the workbench;
Step 2: Align UM4B0 transfer board positioning holes and pins with EVK, and fix
it in the EVK. EVK provides power supply and standard communication interface
for the module to communicate with peripheral devices;

15
NOTE: The RF connector of the board is MMCX, and the suitable connecting wire
should be selected according to the package. The input signal gain at the antenna
interface is optimal between 20 and 36 dB. Please select the appropriate antenna,
antenna cable and online LNA accordingly.
Figure 4-2 Installation Instruction
Step 3: Select the GNSS antenna with appropriate gain, and fix it in a stable, non-
block area, using the coaxial radio frequency cable to connect the antenna to
UM4B0 EVK;
Step 4: Connect the PC to the EVK serial port through direct serial cable;

UM4B0 User Manual
16
Figure 4-3 Connect the Serial Port
Step 5: Connect a 12V adapter to the EVK power input, and switch on to power
the device;
Figure 4-4 Connect the Antenna
Step 6: Open the UPrecise software on the PC;
Step 7: Control the receiver through UPrecise to send commands or to log data.