User Manual

Asset-Link 250 User Manual July 19, 2004

970-00047 Rev. 1.2

5 GPS Connector Specifications

The GPS connector is a standard female FAKRA SMB connector. The shell of the

connector is connected to the Asset-Link chassis. The center pin of the connector is

for the GPS receiver input and output at 50 ohms nominal impedance.

The GPS connector is designed to be connected to an antenna with an integral Low

Noise Amplifier (LNA) for GPS signals.

5.1.1 GPS Connector

The GPS connector has the following characteristics:

Parameter Min Nominal

Max Units

1574 MHz Impedance 50 ohms

1574 MHz Return Loss 6 12 Inf dB

D.C Bias

(GPS Operational)

3.0 3.3 3.6 Volts

10mA<Ibias<40mA

Current Sourcing 10 20 40 mA

D.C. Bias to Open Circuit GPS

not operating

-0.2 0 0.2 volts

Impedance to bias voltage at

D.C., GPS Operational

15 ohms

Imp

edance to Ground at D.C.

GPS not operating

20K 25K 30K ohms

Maximum RF voltage applied

externally

-30 dBm

Table 5-1 GPS Connector Characteristics

5.1.2 GPS Connector Shield

The shield on the GPS connector is directly connected to the Asset-Link ground. For

best results keep the shielded cable from the SMB FAKRA connector against or

surrounded by the metal frame.

5.1.3 GPS Connector Center Pin Voltage Protection

The Asset-Link GPS Connector Center Pin is protected for up to +/-5 volts application

of D.C. As this connection is not expected to be used for vehicular voltage I/O it is

not expected that voltage will be applied to this pin.

5.1.4 GPS Connector Center Pin Short To Ground or Open Protection

The Asset-Link GPS Connector Center Pin has protection for application of a

connection to “Ground” or a “Open”without damage to the GPS receiver electronics.

For this test, the shell of the connector is ground.