The maximum power consumption of the OEM4-G2L (start-up in-rush (<5ms)) is 2.4W. At 3.3 VDC this works out to 727 mA of current.
The maximum operating power consumption (steady state, after in-rush is done) is 1.9W, which at 3.3 VDC would be 576 mA of current.
These numbers include the power consumption while powering a standard dual frequency NovAtel GPS antenna.
We generally recommend using a power supply that is capable of sourcing 1.0 amps at 3.3 VDC for optimal operating results.
Also, because of the low voltage/high current situation, it is advisable to use short power wires, thicker gage wires, or both in order to minimize voltage drop and heat generation on the power supply wires to the OEM4-G2L GPS Card.