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SiPM-based LIDAR read-out chip


Liroc is a 64-channel front-end ASIC designed to read-out silicon photo-multipliers (SiPM) for LIDAR application.
Liroc allows triggering down to 1/3 p.e. and provides low-voltage differential trigger output for each channel with an excellent timing resolution (better than 20ps FWHM) and excellent double-peak separation (100% efficiency on 5ns separated single photo-electrons). Liroc allows fast single photon counting over 100MHz per channel.
An adjustment of the SiPM high-voltage (gain) is possible using a channel-by-channel 6-bit DAC connected to the ASIC inputs. Channel-by-channel calibration on the trigger threshold is also possible thanks to 7-bit DACs. Liroc can be calibrated using the dark noise of the SiPM.
Liroc features a GHz measurement line composed of an RF preamplifier woth pole zero cancellation followed by a fast discriminator and low swing LVDS fast driver.

TRL Technology Readiness Level  4 - ASIC validated in lab environment
Available versions
  • Liroc : available June 2021
Detector Read-Out  SiPM, SiPM array
Number of Channel 64
Signal Polarity Both Positive and Negative
Sensitivity Trigger on 1/10 photo-electron
Timing Resolution 

Double peak separation : better than 5ns on single photo-electron

Time resolution : better than 20ps FWHM on single photo-electron

Dynamic Range up to 15 photo-electron with ToT @ 106 SiPM gain
Packaging & Dimension 
  • FC-BGA 516 20x20mm (Low-inductance flip chip)
Power Consumption

210 mW  - supply voltage 1.2V

Inputs 64 voltage inputs with independant SiPM HV adjustments
  • 64 CLPS (low common mode LVDS)  trigger outputs 
Internal Programmable Features
  • 64 HV adjustment for SiPM (64 x 6 bit)
  • trigger threshold programming (10bits), 64 x 7 bit channel-wise threshold adjustment
  • ASIC-wise polarity selector
  • preamp gain adjustment
  • individual trigger masking and cell powering.
Evaluation systems
  • Evaluation board : Available June 2021

Liroc Block Scheme

 Useful links :

ATTRACT project webpage