Turn ON/OFF Sequence:
for GaN & GaAs SSPAs
Turn ON Sequence: GaN & GaAs SSPAs
1. Mount the SSPA to the heat sink as described in Heat Sinking Requirements.
2. Connect the amplifier to the RF Input and RF Output cables. Ensure there is enough padding or attenuation between the amplifier and the load, so the SSPA (or test equipment) will not be damaged by high VSWR or high power.
3. Adjust the DC power supply voltage(s) to the value(s) specified for the particular SSPA. For example, this might be +30 VDC (or +28 to +50 VDC), +12 VDC, and -5 VDC.
4. Connect the DC power to the SSPA. Apply ALL NEGATIVE voltages to the SSPA FIRST, before applying the positive voltages. For this example, the sequence can be: -5V first, +12V and then +30V. DO NOT slowly turn up the voltages to the SSPA with the power supply or supplies connected.
5. If the unit is a CW SSPA, skip Step 5 and go directly to Step 6. If the unit is a Pulsed SSPA, the amplifier will be ON when the TTL is low; the amplifier will be OFF when the TTL is high or floating. If a different condition is required, consult the factory. Be sure to follow the specified conditions for maximum pulse width and duty cycle when setting the pulsed waveform parameters. If the maximum pulse width and duty cycle are exceeded, permanent damage or degradation may occur.
6. Set the RF generator to small signal level, turn on the RF signal generator to apply RF to the SSPA. Adjust the input power level to the desired range to get full output power.
Turn OFF Sequence (Pulsed & CW)
1. Turn OFF the signal generator.
2. If this is a Pulsed SSPA, turn OFF the pulse generator.
3. ALL external negative voltages should be left ON and CONNECTED until ALL positive voltages have been disconnected.
4. Disconnect positive voltages FIRST.