Power Supply Group Operation - Agilent Technologies PNA Series Service Manual

PNA Series Microwave Network Analyzers
E8361A

Power Supply Group Operation

The A4 power supply assembly is a switching power supply operating at 103 kHz switching
frequency. The input power ranges for the power supply are 90 to 132 Vac or 195 to 250
Vac. The power supply automatically senses the input voltage and switches between these
two ranges.
The dc output voltages are:
• +5.2 V
• −5.2 V
• +9 V
• +15 V
• +15 V standby (always on)
• −15 V
• +22 V
• VCC (5.2 V for the A15 CPU board)
• VDL (3.3 V to the A15 CPU board)
The +15 V standby line remains on continuously whenever the power supply is plugged in.
This line is used to provide power to front panel LEDs and CPU components when the
analyzer is turned off.
An additional +32 V supply line is generated on the A14 system motherboard from the
+22 V supply line.
If the power supply senses an over-voltage or over-current condition on any of
NOTE
the supply lines, the power supply will cycle on and off at a low voltage level
(burp mode).
Service Guide E8361-90001
Theory of Operation
Power Supply Group Operation
5- 29