Parts on Detail

Diamond Detector Secondary Shower Acquisiton System

ICECAL_V3 Mezzanine > ADC41240 and THS4521 Dynamic Performance

1. Parts Tested

THS4524: Fully differential Rail-To Rail Output ampliffier (TID = 1kGy) ADS41240: Quad 12Bit 40MSPS ADC with parallel LVDS outputs. (TID = 10MRad) Procedure: A 1.7Vpp sinusoid (to cover the complete ADC dynamic range 4095 counts) is injected in each ampliffier input, the THS4524 drivers on the board have been configured to perform single to differential conversion as shown on the schematic bellow. Parameters such as SNR, SINAD or ENOB will be analised.

2. The Set-Up

The function generator used is Techtronics AFG3252, with 50 ohms output impedance. Each ADC driver has 50 ohms input impedance, however the set-up is not fully adapted since the splitter used is just a set of Lemo Tees. The function generator "sees" a load of four 50 ohms systems placed in parallel --> 12.5 Ohms. The scope signal is directly injected on the adc drivers, there is no filter to remove signal harmonics.

3.ADC Dynamic Parameters

• Related Student Meeting Presentation:
  • 2016/02/15 --> Beam Secondary Shower Acquisition System: SPS BA5 Intervention (11/02/2016) and ICECAL_V3 Board Testings

Input Signal 1 Khz , Input Signal 2.5 Khz, Input Signal 4KHz, Input signal 1 MHz, Input signal 2.5 MHz, Input Signal 4 MHz, *Input Signal 10 MHz *

ADC Dynamic parameters for 2.5MHz Sinusoidal Input:

3.1. Graphical Summary of ADC Dynamic Parameters

*DS : Information from K.Kloukinas et al 2005. Characterization and production testing of a quad 12 bit 40 Ms/sec A/D converter with automatic digital range selection for calorimetry.

4. Noise Distribution

The board was connected to an Tektronix AFG3252, with the F.Generator powered off, a window of 250us is taken per channel (10000 points per channel @ 40MSPS) and the noise distribution of the ADC and drivers checked with an histogram.

Considering that the ADC Vdiff = 1.8V and LSB = 4.39e-4 V

• Noise sigma ~ 0.35 mV

5. Linearity Check with F.Generator using a Ramp

A triangular waveform is introduced on the four channels in parallel with the F.Generator Tektronix AFG3252. Only the first ramp signal from 0 to 4095 in the time domain has been considered for a linear fit, giving as a result a linear sweep in signal amplitude. A linear fit is performed on this segment of signal, the residuals of the fit in ADC counts show the approximated linearity of the ADC and Drivers.

Relative Linearity Error:

Absolute Linearity Error: