Theory of Operation
Each acquisition ASIC contains samplers and peak detectors, an ampli
fi
er, an A/D
converter, and the trigger logic. The digitized waveform samples are transferred
to the processing and display ASIC. In four-channel systems, the two acquisition
ASICs are interconnected so that a trigger on one ASIC can produce a trigger
on the other.
The processor system adds the microprocessor and FLASH ROM to the
processing and display system. The processor system interprets the front-panel
control changes detected by the display ASIC, provides control parameters based
upon user setting requests, computes waveform measurements, and manages
the internal and external peripherals. Saved setups, waveforms, and calibration
constants are stored in nonvolatile memory (NVRAM). The processor system
shares DRAM with the display system.
Processing and Display
System
The processing and display system consists of the display ASIC, DRAM, and
system oscillator. Digitized acquisition samples are received by the display
ASIC and stored in DRAM. Once data are received by the display ASIC, various
corrections are applied, display rasterization is performed, and the waveform is
placed into a display buffer. At the same time, the waveform is being read from
the display buffers and written to the LCD. Additional circuitry in the display
ASIC supports scanning of the front panel, provides DRAM refresh, processes the
clock, and performs various memory mapping tasks required by all elementary
microprocessor-based systems. In a four-channel system, the two display ASICs
are interconnected so that one ASIC may provide display information for the
second.
The processing and display system handles some of the computational tasks.
Other tasks are performed by the processor system. Since all array processing
is performed in the processing and display system, no computations can be
performed that involve data from two different channel sets. Thus, subtracting
channel 3 data from channel 2 is prohibited.
Probe Compensation
The PROBE COMP and ground terminals are provided for probe adjustment.
Acquisition Board Power
The IO board supplies the Acquisition board with 5.0, 3.0, 3.3, and 15 V
DC
. These
sources are used directly or as sources for other converters on the Acquisition
board. The Acquisition board supplies 35 volts used for series-strings of LEDs on
the front panel for button illumination.
TPS2000B Series Digital Storage Oscilloscopes Service Manual
15
Summary of Contents for TPS2000B Series
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Page 12: ...Service Safety Summary viii TPS2000B Series Digital Storage Oscilloscopes Service Manual...
Page 24: ...Specifications 10 TPS2000B Series Digital Storage Oscilloscopes Service Manual...
Page 26: ...Operating Information 12 TPS2000B Series Digital Storage Oscilloscopes Service Manual...
Page 32: ...Theory of Operation 18 TPS2000B Series Digital Storage Oscilloscopes Service Manual...
Page 46: ...Performance Verification 32 TPS2000B Series Digital Storage Oscilloscopes Service Manual...
Page 86: ...Diagrams 72 TPS2000B Series Digital Storage Oscilloscopes Service Manual...