Analog To Digital Board - Hologic QDR 4500 Technical Manual

Table 2-22. Analog Digital Converter Board/Integrator Multiplexor Board
Interconnection Descriptions
Signal
Signal
(see Note 1)
MA1, MA2 IN0, IN1
MB1, MB2 IN6, IN7
MC1, MC2 IN2, IN3
MD1, MD2 IN4, IN5
MUX0- MUX3 IN8 IN9
IN10, IN11
GPL1, GPL2 IN14, IN15
MGN1, MGN2 IN12, IN13
LTCH1, IN16
LTCH2
INTEG IN18
DISC IN19
TSTEN IN20
BB0
BB1
BB2
BB3
+15V
15V_RET
-15V
+5V
GND
Note 1. Some signal names are labeled differently on different schematic drawings.

Analog To Digital Board

The Analog To Digital (ADC) board converts analog signals received from the
Integrator/Multiplexor board to a digital format.
Analog signals from the Integrator/Multiplexor board are applied to differential amplifiers on the
ADC board in four groups of up to 64 channels. Outputs from the differential amplifiers are
combined in a final multiplexor consisting of four analog switches. The multiplexed signals pass
through a programmable gain amplifier and summing amplifier before being applied to an A/D
converter. A one volt fixed DC offset is inserted at the summing amplifier to insure that no
2-30
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QDR 4500 Technical Manual
Description
Selects integrator channels to be
returned to the Analog/Digital
Converter.
Controls integrator/multiplexor
gains.
Latches control signals on
Integrator/ Multiplexor.
Controls signal integration.
Discharges the integrating
capacitors.
Test signal used to verify the
operation of the integrators and
multiplexor when no X-rays are
present.
Integrator signals to the
Analog/Digital Converter.
Powers the amplifiers and switches
of the Integrator/Multiplexor
board and powers the Solid State
Detector boards.
Powers the digital circuitry of the
Integrator/Multiplexor board.
ADC
Pins PINS
JP4-1, JP4-3 JP7-1, JP7-3
JP4-13, JP4-15 JP7-13, JP7-15
JP4-5, JP4-7 JP7-5, JP7-7
JP4-9, JP4-11 JP7-9, JP7-11
JP4-17, JP4-19, JP7-17, JP7-19,
JP4-21, JP4-23 JP7-21, JP7-23
JP4-29, JP4-31 JP7-29, JP7-31
JP4-25, JP4-27 JP7-25, JP7-27
JP4-33 JP7-33
JP4-37 JP7-37
JP4-35 JP7-35
JP4-39 JP7-39
JP4-41 JP7-41
JP2-2 JP11-2
JP2-6 JP11-6
JP2-10 JP11-10
JP2-14 JP11-14
JP1-5 JP10-5
JP1-4 JP10-4
JP1-3 JP10-3
JP1-2 JP10-2
JP1-1 JP10-1
I/M