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printed at  08.08.2008
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Analog-to-Digital Converter Model 7070

(identical in construction to the T8100 of Target-Systems GmbH)

 

FEATURES

  • Wilkinson ADC with 100 MHz clock rate
  • Full 8k Conversion Gain and Range
  • Digital Offset in 256 channel increments
  • Instantaneous Dead-Time display
  • Lower Level and Upper Level Discriminator
  • Pulse Height Analysis with automatic peak detection
  • Designed for easy interfacing to Computers

DESCRIPTION
The model 7070 is a Wilkinson-type Analog-to-Digital Converter with a 100 MHz clock rate. The 7070 is ideally suited for applications in nuclear- and X-ray Spectroscopy. The upper- and lower-level discriminator has a separate output on the rear panel.

SPECIFICATION

INPUTS (front panel) Signal Input: BNC-Connector accepts +25mV to +8V (standard / +10V optional) linear pulses, Zin = 1k Ohm, risetime: > 100ns to 100µs, fall time: 200ns to 100µs, 0.5µs flat top width, dc coupled. Gate: BNC-Connector accepts positive TTL

OUTPUTS (rear panel) Data

13 bit binary data lines and data transfer commands, Amphenol D-Sub-connector.

SCA-output: BNC-connector, TTL pulse approx. 0.5µs duration. One output pulse for each input signal that falls between the ULD and LLD setting.

INDICATORS DEADTIME:

LED-bar indicates activity of the ADC. Range 0 to 100% deadtime

Front Panel Controls Offset:

Digital Offset, range 0 to 8k in steps of 256 channels.

Conversion Gain: Six position rotary switch selects quantisation of 256, 512, 1k, 2k, 4k, or 8k channels for full scale input. Data is compressed to 8, 9, 10, 11, 12 and 13 bits.

 

LLD: Precision potentiometer sets the lower level discriminator.

ULD:

Precision potentiometer sets the upper level discriminator.

Zero: Precision potentiometer sets the "zero" level from 0 to +/-200mV.

Coinc - /Coinc: Toggle switch selects coincidence or anticoincidence mode.

 

 

PERFORMANCE

Conversion Time: (1.0 + 0.01N) µs, where N is the channel address generated by the 7070 ADC (including digital offset) ADC Deadtime: time-to-peak + 1µs + conversion time. Typical ADC deadtime using a Gamma-spectrum containing I-131, Ru-103, Cs-137 and Cs-134g measured with a Germanium detector:

Integral non-linearity: less than +/-0.05% of full scale over top 99% of selected range. Differential non-linearity: less than +/-0.75% over top 99% of selected range. Gain stability: better than 50 ppm/oC Baseline stability: 50µV/oC

Conversion
Gain
1024
2048
4096
8192

Average deadtime
/conversion
3.7µs
7.1µs
13.9µs
27.4µs

Temperature range: 0oC to +50oC Power Requirements:
+24V, 80mA, -24V, 120mA, + 6V, 600mA, -6V, 20 mA

Physical Size: single width NIM module (1.35 x 871 inches; 3.43 x 22.13 cm) as per TID - 20893 Shipping weight: 1.2 kg (net 0.8 kg)

 

 

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