Liroc

SiPM-based LIDAR read-out chip

Liroc

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
Outputs	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