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NEO-8Q / NEO-M8 - Hardware integration manual 

UBX-15029985 - Production information 

Hardware description

  

Page 9 of 10 

C1-Public  

 

 

 

Power control 

The power control feature allows overriding the automatic active/inactive cycle of power save mode. 
The state of the receiver can be controlled through the 

EXTINT  (EXTINT0 

on 

NEO-M8T) 

pin. The 

receiver can also be forced OFF using 

EXTINT (EXTINT0 

on 

NEO-M8T) 

when power save mode is not 

active. 

Frequency aiding 

The 

EXTINT (EXTINT0 

on 

NEO-M8T) 

pin can be used to supply time or frequency aiding data to the 

receiver. 

For time aiding, hardware time synchronization can be achieved by connecting an accurate time pulse 
to the 

EXTINT (EXTINT0 

on 

NEO-M8T) 

pin.  

Frequency aiding can be implemented by connecting a periodic rectangular signal with a frequency up 
to 500 kHz and arbitrary duty cycle (low/high phase duration must not be shorter than 50 ns) to the 

EXTINT (EXTINT0 

on 

NEO-M8T) 

pin. Provide the applied frequency value to the receiver using UBX 

messages. 

1.5.3

 

SAFEBOOT_N 

The 

SAFEBOOT_N

 pin is for future service, updates and reconfiguration. 

On the  NEO-M8T  module,  a  configurable  TIMEPULSE2  signal  can be programmed on 

TP2/SAFEBOOT_N

 

Do not pull low during reset. 

1.5.4

 

D_SEL: Interface select 

The 

D_SEL

 pin selects the available interfaces. SPI cannot be used simultaneously with UART/DDC. If 

open, UART and DDC are available. If pulled low, the SPI interface is available. See the corresponding 
product data sheet. 

1.5.5

 

TIMEPULSE (TIMEPULSE1 on NEO-M8T) 

On NEO-8Q and NEO-M8 series modules, a configurable time pulse signal is available. By default, the 
time pulse signal is configured to one pulse per second. For more information, see the u-blox 8 / u-blox 
M8 Receiver Description including Protocol Specification [4]. 

1.5.6

 

TIMEPULSE2 

On the 

NEO-M8T

  module,  a  configurable  TIMEPULSE2  signal  can be programmed on 

TP2/SAFEBOOT_N. 

For more information, see the u-blox 8 / u-blox M8 Receiver Description including Protocol 
Specification [4]. 

 

The TIMEPULSE2 output must 

not

 be held LOW during start-up. 

1.5.7

 

LNA_EN: LNA enable 

On 

NEO-M8N,  NEO-M8J,

 

NEO-M8Q, NEO-M8T

  and 

NEO-8Q

  modules,

 

in  power  save  mode, the 

system can turn on/off an optional external LNA using the 

LNA_EN

 signal in order to optimize power 

consumption.  

Signals: "high" = Turn ON LNA, "low" = Turn OFF LNA

 

Summary of Contents for NEO-M8N

Page 1: ...9985 R08 C1 Public www u blox com NEO 8Q NEO M8 u blox 8 M8 GNSS modules Hardware integration manual Abstract This document describes the features and specifications of u blox NEO 8Q and NEO M8 series...

Page 2: ...M Q T Declaration of Conformity DoC is available at www u blox com in Support Product resources Conformity Declaration This document applies to the following products Product name Type number ROM FLAS...

Page 3: ...rnal interrupt 8 1 5 3 SAFEBOOT_N 9 1 5 4 D_SEL Interface select 9 1 5 5 TIMEPULSE TIMEPULSE1 on NEO M8T 9 1 5 6 TIMEPULSE2 9 1 5 7 LNA_EN LNA enable 9 1 6 Electromagnetic interference on I O lines 10...

Page 4: ...9985 Production information Contents Page 4 of 5 C1 Public 4 2 Soldering 19 4 3 EOS ESD EMI precautions 22 4 4 Applications with cellular modules 25 Appendix 27 A Glossary 27 B Recommended parts 27 Re...

Page 5: ...attery supply is not interrupted For the NEO M8N and NEO M8J modules configuration can be saved permanently in SQI flash 1 3 Connecting power The u blox NEO 8Q and NEO M8 series modules have three pow...

Page 6: ...ill runs providing a timing reference for the receiver This operating mode is called Hardware Backup Mode which enables all relevant data to be saved in the backup RAM to allow a hot or warm start lat...

Page 7: ...Depending on the characteristics of the LDO U1 it is recommended to add a pull down resistor R11 at its output to ensure VDD_USB is not floating if the LDO U1 is disabled or the USB cable is not conn...

Page 8: ...can be enabled and configured by AT commands sent to the u blox cellular module supporting the feature For more information see the GPS Implementation and Aiding Features in u blox wireless modules 8...

Page 9: ...ure service updates and reconfiguration On the NEO M8T module a configurable TIMEPULSE2 signal can be programmed on TP2 SAFEBOOT_N Do not pull low during reset 1 5 4 D_SEL Interface select The D_SEL p...

Page 10: ...ded high impedance line it is possible to generate noise in the order of volts and not only distort receiver operation but also damage it permanently On the other hand noise generated at the I O pins...

Page 11: ...rial input Internal pull up resistor to VCC Leave open if not used If pin 2 low SPI MOSI USB USB_DM 5 I O USB I O line USB bidirectional communication pin Leave open if unused USB_DP 6 I O USB I O lin...

Page 12: ...gn This is a minimal design for a NEO 8Q and NEO M8 series GNSS receiver Figure 4 NEO 8Q NEO M8 passive antenna design NEO M8M can support passive antenna but for optimal operation it requires an exte...

Page 13: ...re with the antenna performance Passive antennas do not require a DC bias voltage and can be directly connected to the RF input pin RF_IN Sometimes they may also need a passive matching network to mat...

Page 14: ...In that case the LNA must be placed close to the passive antenna Figure 8 NEO M8N J T Q and NEO 8Q module design with passive antenna and an external LNA The LNA_EN pin LNA enable can be used to turn...

Page 15: ...nna e g 3 0 V use the filtered supply voltage available at pin VCC_RF as shown in Figure 9 For exact pin orientation see the corresponding product data sheet Active antenna design using VCC_RF pin to...

Page 16: ...ignal tracking Sources can include co located power devices cooling fans or thermal conduction via the PCB Consider the following questions when designing in the module Is the receiver placed away fro...

Page 17: ...O M8 series Remarks for migration Pin name Typical assignment Pin name Typical assignment 1 SAFEBOOT_N Leave open SAFEBOOT_N Leave open No difference 2 SS_N SPI slave select D_SEL Selects the interfac...

Page 18: ...used RESERVED Leave open 17 RESERVED Leave open RESERVED Leave open No difference 18 SDA DDC data SDA DDC data SPI CS_N No difference for DDC If pin 2 low SPI chip select 19 SCL DDC clock SCL DDC cloc...

Page 19: ...older joints on the connectors half vias should meet the appropriate IPC specification Reflow soldering A convection type soldering oven is highly recommended over the infrared type radiation oven Con...

Page 20: ...ter soldering the u blox module consider an optical inspection step to check whether The module is properly aligned and centered over the pads All pads are properly soldered No excess solder has creat...

Page 21: ...ing for example pins 1 and 15 and continue from left to right Rework The u blox module can be unsoldered from the baseboard using a hot air gun When using a hot air gun for unsoldering the module a ma...

Page 22: ...serve strict EOS ESD EMI handling and protection measures To prevent overstress damage at the RF_IN of your receiver never exceed the maximum input power see the corresponding product data sheet Elect...

Page 23: ...employ additional ESD protection measures Using an LNA with appropriate ESD rating can provide enhanced GNSS performance with passive antennas and increases ESD protection Most defects caused by ESD...

Page 24: ...ceiver or resulting in unstable performance In addition to EMI degradation due to self jamming see section 1 5 any electronic device near the GNSS receiver can emit noise that can lead to EMI disturba...

Page 25: ...dditional input filter is needed on the GNSS side to block the high energy emitted by the cellular transmitter Examples of these kinds of filters are the SAW Filters from Epcos B9444 or B7839 or Murat...

Page 26: ...that are different from the GNSS carrier see Figure 16 The main sources are wireless communication systems such as cellular CDMA WCDMA Wi Fi BT etc Figure 16 Out band interference signals Measures ag...

Page 27: ...nded parts Recommended parts are selected on data sheet basis only Other components may also be used Part Manufacturer Part ID Remarks Parameters to consider Diode ON Semiconductor ESD9R3 3ST5G Stando...

Page 28: ...5 Array type For data signals 4 circuits in 1 package Feed through Capacitor Murata NFM18PC NFM21P 0603 2A 0805 4A Rs 0 5 Resistor 10 10 min 0 250 W Rbias 560 5 R2 100 k 5 R3 R4 Table 6 Recommended pa...

Page 29: ...including Protocol Specification Public version UBX 13003221 5 GPS Antenna Application note GPS X 08014 6 GPS Compendium GPS X 02007 7 I2C bus specification Rev 6 4 April 2014 http www nxp com docume...

Page 30: ...ntended use case for EMI in section 4 3 EOS ESD EMI precautions updated legal statement on the cover page and added Documentation feedback e mail address in contacts page R05 10 Jul 2019 jesk Clarifie...

Page 31: ..._ap u blox com Regional Office China Beijing Phone 86 10 68 133 545 E mail info_cn u blox com Support support_cn u blox com Regional Office China Chongqing Phone 86 23 6815 1588 E mail info_cn u blox...

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