Power Supply

There are two options for powering Certus OEM, either a wide input 9-30 VDC that must pass through an onboard regulator or a clean and regulated 5 VDC supply. See Connector Pin-out for details

Note: Only one power supply should be connected to the unit at any one time. Connecting power supplies to both inputs may result in damage to the unit.

On start-up of the Certus OEM the device will initially draw an increased impulse current (2 A for 2 microseconds) whilst it charges on board capacitors. It is important that the user's circuit is tolerant to these small impulses on start-up to avoid unsuccessful power up. It is recommended that a supply is selected that can provide a maximum current of 2 A. Switch-mode supplies are suitable as Certus OEM has on-board filters to remove any supply noise and ripple.

9-30 V Input

A wide range 9-30 V input is available which connects to Certus OEM’s onboard regulator. The power supply should be able to supply the maximum current at the chosen voltage, calculated from the maximum power indicated in Hardware Specifications. For the avoidance of doubt, if wiring your own JST connector, observe the + and – polarity indicated on the PCBA.

Take care when using a supply voltage close to the under-voltage lockout of 9.1 V, as small voltage changes could engage the under-voltage shutdown and potentially oscillate between the on and off state unexpectedly. It is recommended that the unit is always run at 9.5 V or higher.

Regulated 5 V Input

The 5 V input is only rated for inputs from 4.95 V to 5.05 V, exceeding 5.5 V can cause permanent damage to the unit. The 5 V supply must be low noise (< 20 mV peak-to-peak).