gmoverid-skill

Sky130A open PDK workflow for ngspice-based analog simulation. Use when an agent needs to install or locate Sky130A via Volare/open_pdks, run process-corner PVT simulations, run process Monte Carlo or mismatch-aware smoke tests, instantiate sky130_fd_pr devices, or validate Sky130A examples such as MOS Id-Vgs, ring oscillators, and five-transistor OTAs.

ngspice simulation tutorial and template skill. Provides nine standard simulation examples: (1) Transient — RC charging voltage and current; (2) DC — NMOS Id-Vds family curves; (3) AC — RC low-pass filter frequency response; (4) Noise — RC filter output noise spectral density and kT/C; (5) Transient — sample-and-hold switch comparison; (6) Transient — kT/C noise time-domain statistical measurement; (7) DC — NMOS current mirror output characteristics; (8) AC — common-source amplifier frequency response; (9) DC — transmission gate on-resistance. Built-in PTM 180/45/22nm models included.

Complete PTM (Predictive Technology Model) MOSFET model library from mec.umn.edu/ptm, covering all nodes: bulk conventional 180/130/90/65nm, bulk HP/LP 45/32/22nm (BSIM4), and PTM-MG multi-gate FinFET 7/10/14/16/20nm (BSIM-CMG, HP + LSTP). No manual downloads required after installing this skill. Independent of the gmoverid skill — can be used directly in any ngspice/HSPICE project.

gm/ID transistor characterization and design methodology, based on ngspice + Python. Two independent workflows: (1) Characterization — generates three standard curve sets for any MOSFET model: gate capacitance (Cgg/Cgs/Cgd/Cgb vs Vgs), gm/ID four-quadrant characteristics (gm/Id vs Vov, Id/W vs gm/Id, fT vs gm/Id, gm·ro vs gm/Id), and IV characteristics (linear/log Id vs Vov, output curves). Supports 180 nm single-node and 45/22 nm HP multi-node flows with built-in PTM model files (180/45/22 nm) — no extra downloads required. (2) Design — the GmIdTable class builds a lookup table from simulation data (cached to logs/cache/) and provides lookup(), size(), size_from_ft(), size_from_gmro() APIs for NMOS/PMOS transistor sizing using the gm/ID methodology. Only depends on the ngspice skill. Use this skill when setting up or extending a gm/ID characterization project, generating characteristic curves, interpreting design curves, or sizing transistors by the gm/ID method.