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PIN Diode and Low Gain Silicium Detector Read-Out Chip


SKIROC 2A is a 64-channel front-end ASIC designed to readout silicon PIN diodes. Each channel is made of a variable-gain and low-noise charge preamplifier followed by two shapers – one with a gain of 1 and the other with a gain of 10 – to provide a charge measurement from 0.2 fC up to 10 pC. A time tagging is performed by a 12-bit TDC ramp. The charges and times are stored in a 15-depth Switched Capacitor Arrays (SCA), the values of which are converted by a multi-channel 12-bit Wilkinson ADC and sent to an integrated 4 Kbytes memory. The analog value of the charge is also available on an output pin. The trigger chain is composed of a high gain fast shaper and a discriminator and allows each channel to auto trigger down to 0.2 fC. Thresholds of the 64 discriminators are set by a common 10-bit DAC and an individual 4-bit DAC per channel. Each discriminator output is sent to an 8-bit delay cell (delay time tunable between 100 ns and 300 ns) to provide the Hold signal for the SCA cells of the slow channel. The power consumption is 6.2 mW/channel and each stage can be individually shut down when not used.

TRL Technology Readiness Level 8 - Full system using ASIC running
Available versions
  • Skiroc 2A
Detector Read-Out  Si PIN Diodes
Number of Channel 64
Signal Polarity Positive
Sensitivity Trigger on 0.2fC
Timing Resolution  N/A
Dynamic Range 10 pC, Integral Non Linearity <1%
Packaging Dimension 
  • BGA400 17x17mm
Power Consumption

6.2 mW/ch, power supply : 3.3 V

Power pulsing

Inputs 64 current inputs

1 multiplexed analog charge output 

12-bit charge and time measurment

Trigger 0R of the 64 discrimators 

Internal Programmable Features
  • Common gain adjustment for the input preamps from 400fF up to 6pF (4 bits)
  • common trigger threshold adjustement (10 bits) and individual threshold (4 bits)
  • 12-bit charge and time measurement
  • 64 trigger masks
  • multiplexed analog outputs
Evaluation system
  • Evaluation board : available