Advanced Energy VarioMatch Match Network VM 1000 Platform, User Manual, Page: 24 / 194

Advanced Energy ®
A DC bias measurement circuit (avai l able on most units) permits the DC self bias
voltage created in the load to be monitored. The bias vo l tage is scaled down by a
factor of 1 :400 (if not otherwise stated) to a safe, convenient value. The DC bias test
voltage delivered by the VarioMatch match network always is positive, even if the
actual self bias voltage in the chamber is negative.
VarioMatch match networks are completely self contained and require no additional
ex t ernal components; all that is required for operation is an AC
MAINS
connection.
No additional controller is required if the network is operated in conjunction with an
AE RF generator; manual controls for the network are incorporated in the generator
itself. An additional controller is necessary only if manual operation withou t an AE
RF generator is desired.
OPERATING MODES
2-2
The match ne t work can operate in the following modes:
• Automatic tune mode
AE recommends automatic tune mode for standard operation. In automatic tune
mode, a fast analog control signal measures amplitude and phase, and
automatically drives the capacitors to transform the impedance of the chamber to
the impedance that the generator requires.
Automatic tune mode requires no user interface.
• Manual tune mode
In manual tune mode, the automatic tuning feature is disabled, and the capacitor
positions are controlled only through the INTERFACE port.
Product Overv i ew and T heory
57020080-00D