Agilent Technologies 35670A Service Manual page 305

BNC
Input
Analog
Digital
CPU
DC-DC Converter
Display
Memory
NVRAM
Disk Drive
Keyboard Controller
Primary Keypad
Agilent 35670A
Overall Block Diagram
The following figures show the overall block diagrams for both the two channel and
the four channel analyzer. Each block in the diagrams represents a functional block in
the analyzer. The assembly that performs the function is listed in the block.
Contains the BNC connectors for both input channels and the source. For the four channel
analyzer, the BNC assembly contains the BNC connectors for all four input channels. Both
BNC assemblies filter the input channels HIGH (BNC center conductor) and LOW (BNC shell)
input signals to reduce noise at the inputs.
Buffers, attenuates, amplifies, and filters the input signals. The input assembly also provides
common mode and differential overload detection, and half-range detection. The two channel
analyzer contains one A1 Input assembly and the four channel analyzer contains two A2 Input
assemblies.
Converts the input signals from the Input assembly (or assemblies) to digital data. The Analog
assembly also converts the digital data from the Digital assembly's digital source to the analog
source signal. For the two channel analyzer, the analog source signal is routed to the Rear
Panel assembly and to the BNC assembly. For the four channel analyzer, the analog source
signal is routed only to the Rear Panel assembly.
Prepares the digital data from the Analog assembly for the CPU assembly. This assembly also
generates the digital source data for the Analog assembly.
Controls the analyzer. The following is a partial list of the operations it performs:
Configures the assemblies
•
Controls the Disk Drive assembly
•
Controls the Display assembly
•
Initiates the power-up sequence and calibration routine
•
Processes digital data from the Digital assembly
•
Computes the Fast Fourier Transform (FFT)
•
Monitors for a keystroke
•
Monitors the assemblies for overloads or other error conditions
•
Runs the self tests
•
Generates the driver supply voltages for the Display assembly.
Offers a view of the processed data. See the description of the Display Controller for the "A7
CPU" later in this chapter for further details.
Contains RAM, NVRAM, ROM, and the battery-backed real time clock for the CPU assembly.
Provides the CPU assembly with additional NVRAM. This assembly is optional.
Stores and retrieves information on 3.5-inch flexible disks.
Tells the CPU assembly which key was pressed.
Consists of hardkeys and an RPG.
Circuit Descriptions
Overall Instrument Description
8-3