Service manual

8 157
Theory of Operation
OVERALL OPERATION
8. Theory of Operation
Processor), the A52 LCD, and the A53 FDD. These assemblies combine to provide digital
control for the analyzer.
Source: The source group consists of the A7 synthesizer, the A2 Hc Amp., and the A60
high stability frequency reference(option 1D5 only). The source generates all analog
signals in the analyzer, a phase-locked test signal to the device under test, a DC bias signal
to the device under test, IF signals for the transducer group and the vector ratio detector,
and a sampling signal for the A/D converter.
Transducer: The transducer group consists of the A3 Hp Amp., A4 Lc Amp., A5 IV
Converter & Lp Amp., and the A6 Vector Generator. The transducer group balances the
range resistor current with the DUT current to maintain a zero potential at the low
terminal(Lp) and transforms the DUT impedance, or admittance, into two AC signals.
Vector Ratio Detector: The A8 board is the vector ratio detector. The vector ratio detector
converts the two AC signals from the transducer group into digital data.
The following pages describe the operation of the functional groups.
Simplified block diagrams illustrate the operation of each functional group. The detailed
analog section block diagram is provided at the end of this chapter.