- Grace, C;
- Braga, D;
- Chen, H;
- Christian, D;
- Dabrowski, M;
- Deptuch, G;
- Dwyer, D;
- Fried, J;
- Gao, S;
- Hoff, J;
- Holm, S;
- Lin, C-J;
- Lopriore, E;
- Lu, Y;
- Luk, K-B;
- Miryala, S;
- Prakash, T;
- Richardson, H;
- Shenai, A;
- Tarpara, E;
- Vernon, E;
- Zhang, J
The second and final version of ColdADC, called ColdADC_P2, is presented. ColdADC_P2 is a 16-channel, 12-bit, 2 MS/s digitizer application-specific integrated circuit (ASIC) intended for use inside the DUNE Far Detector. ColdADC_P2 contains two 16 MS/s pipelined analog-to-digital converters (ADCs) that each digitizes the output of eight sample-and-hold amplifiers (SHAs). Because the application requires immersion in liquid argon (LAr), ColdADC_P2 was developed using specialized design techniques for long-term reliability in cryogenic environments and a customized cryogenic standard cell library. ColdADC_P2, with a die area of approximately 52.4 mm2 and fabricated in 65-nm CMOS technology, achieves 130- μ V rms noise performance and 11.8-bit effective-number-of-bits (ENOB) at a temperature of 77 K, with channel-to-channel crosstalk of < 0.06% while dissipating 338 mW (21 mW per channel). Residual nonlinearity that is consistent with dielectric absorption in the capacitors internal to the ADC is corrected using a lookup table.