Analog-to-Digital Converter (ADC)

Analog-to-Digital Converter (ADC) Model 4010

The model 4010 ADC is a high resolution Wilkinson type analog to digital converter with 13 bit conversion range, the unit that digitizes the input pulse height and assigns it to a specific channel. The use of state of the art integrated circuitry provides excellent performance and stability. The 4010 is a single NIM mode that is specifically designed for use in nuclear and x-ray spectroscopy. Excellent integral and differential, high conversion speed and good channel profile make the 4010 an ideal ADC for higher resolution Germanium detectors in neutron and gamma timing and separation experiments.

Analog to digital converter performance

 When a pulse enters the MCA, two events are initiated as shown in following figure:

1. A capacitor starts charging.
2. An input gate prevents the acceptance of another pulse until the previous one is fully processed and registered.

The capacitor keeps charging until the peak of the pulse is reached. At that point in time, two new events are initiated:

1. The voltage on the charged capacitor is discharged by a constant current.
2. An oscillator clock starts. The clock stops its oscillations when the capacitor is fully discharged.

The number of oscillations during this time-called rundown or conversion time -is proportional to the pulse height and constitutes the information that determines the channel number in which that pulse will be stored.

 

Specification

 Inputs

SIGNAL IN

• Accepts Signal: positive or bipolar pulses (positive portion leading).
• Input range: 25 mV to 10 V
• Input impedance: 1000 Ω.
• Rise time: 100 ns to 100 μs
• Fall time: 200 ns to 100 μs
• Width: 0.5 μs minimum
• Input couple: DC – coupled
• Connector: front panel BNC

 

GATE IN

• Accepts signal: positive TTL level or signal width 100 ns.
• Input Impedance: approx. 4.7 kΩ (pull-up).
• Connector: front panel BNC.

Output

SCA

• Connector: rear panel BNC connector.
• Output type: positive TTL output.
• Output width: approx. 1 μs.
• Output pulse: appears for every event that corresponds to an input signal with an amplitude that falls between LLD and ULD setting.

 

Indicator

Dead time LED: Bar graph display for dead time 0% to 100%.

 

Performance

• Conversion time: (1.0 + 0.0125N) μs – where N is the channel address generated by the model 4010 ADC, N is the selected range inclusive of the selected digital offset
• Average dead time: Conversion Time/3
• ADC dead Time: Time to peak + conversion time + transfer time to MCA. (The ADC 4010 has a one word buffer which normally eliminates the transfer time)
• Linearity: Integral Non linearity <±0.05% of full scale over top 99% of range.
• Differential Non linearity:  <±1 % of full scale over top 99% of range

 

Power requirements

 

 

 

 

Physical

• Size: Single width NIM model
• Weight: 0.8 kg
• Shipping weight: 1 kg

 

Calibration

• Put the instrument inside bin.
• Connect the 3600 amplifier output to the instrument input.
• Connect the instrument output to MPA or MCB using the supplied cable
• Set the LLD, ULD, and ZERO potentiometers.

 

Delivery Test

• Power test
• Match test the amplifier output with MCA input
• Stability test
• Spectroscopy test with DAS software

 

Installation Requirements

• Laboratory
• A table for placing device
• Bin power supply model 8000 or 8010
• BNC cable
• Detector
• Amplifier and preamplifier
• Computer
• The equipped room with an air conditioning for constant temperature and humidity
• Power
• Pulse Generator

 

Long Term Warranty And After Sales Service