PCB Integration

Refer to Quickstart, for a summary of steps to quickly get started.

Certus MiniOEM has been designed to allow for quick and easy integration into the customer's own PCB (Printed Circuit Board).

PCB Mechanical Mounting

Certus Mini OEM mounts to its target PCB through the use of two mounting holes on the aluminium frame. The aluminium frame is designed to achieve effective mating height for the board to board connector without any additional components. Once the Certus Mini OEM is connected to the target PCB, two M1.6 screws and washers and nuts on the back side of the target PCB are used to hold the Certus Mini OEM in place. The length of the M1.6 screws will be depended on the thickness of the target PCB. M1.6x6mm screws are recommended for 1.6mm thickness target PCBs.

Certus Mini OEM courtyard dimension

Certus Mini OEM footprint dimension

Refer to OEM Development Board specific for schemas.

Mounting screw torque

Torque required for the tightening of screws from the Certus Mini OEM to the PCB board is: 2 cNm ± 3%.

Note: Certus Mini OEM sensors are susceptible to flex from the PCB board. Over tightening the screws will cause the board to flex, which will impact sensor readings.

OEM Electrical Connector

The electrical connection to the Certus Mini OEM PCB is through a Hirose DF40 series 40 pin micro pitch board to board connector. These connectors have shock absorbing features, a large self-alignment distance and high contact reliability. A positive click should be felt when successful mating occurs between Certus Mini OEM and the target board.

The manufacturers part number for the required PCB connector is:

Manufacturer compatible PCB connector part numbers:

  • Hirose Part #: DF40TC-40DP-0.4V(51)

  • Hirose Part #: DF40C-40DP-0.4V(51)

  • Hirose Part #: DF40C-40DP-0.4V(58)

Alternative compatible PCB connector part numbers:

  • Digikey Part #: 26-DF40TC-40DP-0.4V(51)CT-ND

  • Digikey Part #: H11624CT-ND

  • Digikey Part #: DF40C-40DP-0.4V(58)-ND

  • Mouser Part #: 798-DF40TC40DP04V51

  • Mouser Part #: 798-DF40C40DP0.4V51

  • Mouser Part #: 798-DF40C40DP0.4V58

Note: The connector is not designed for the Certus MiniOEM to be plugged in whilst power is applied to the user's PCB.

Note: The connector mating cycles should not exceed 50 cycles to ensure connector reliability.

Interoperability with Different Voltage Systems

The Certus Mini OEM operates with 3.3V signal levels. Its inputs are designed to tolerate 5V signals from connected interfaces. If your target system requires a different voltage level for compatibility, you should use a voltage level translator.

To facilitate this, a 3.3V supply is available on pin 7 of the Certus Mini OEM connector. This supply can provide up to 25mA of current and must be properly decoupled if powering an external circuit.

Reset Line

The reset line is internally pulled high on Certus Mini OEM. This pin must be left floating for normal operation. If a user wishes to reset Certus Mini OEM, the pin can be pulled low externally to force a reset. This signal must not driven high as it will prevent the Certus MiniOEM from functioning correctly. The reset line track length should be kept to a minimum to avoid noise.

Power Supply

The power supply is a nominal 5V DC. The unit is only rated for inputs from 4.5 V to 5.5 V. Exceeding 6 V, or reversing the polarity, can cause permanent damage to the unit.

Power filtering has been built into Certus Mini OEM, however it is still recommended that the power supply be low noise (< 20mV peak-to-peak). Switch-mode supplies are a suitable power source.

The power supply should support providing a maximum current of 0.5A. On start-up, the Certus Mini OEM will initially draw an increased impulse current (~400mA for 2 microseconds) whilst it charges on board capacitors. The circuit board must be tolerant to these small impulses on start-up to avoid unsuccessful power up.

U.FL RF Connector

Note: Applicable to N and D variants.

Certus MiniOEM's antenna connection is through an u.FL connector (or equivalent, such as an IPEX MHFI) on the board. A U.FL to SMA adapter cable should be used to allow connection to standard GNSS antennas. The U.FL connector on Certus Mini is fragile and should be handled with care. It is not designed for repeated connection and disconnection.