sycan.components.active.mosfet_l1

Shichman-Hodges Level 1 MOSFET, polarity-aware (NMOS / PMOS).

The model equations below are written in “effective” form. With

pol = +1 for NMOS, -1 for PMOS V_GS_eff = pol * (V(gate) - V(source)) V_DS_eff = pol * (V(drain) - V(source))

the conduction condition in both cases is V_GS_eff > V_TH and V_DS_eff >= V_GS_eff - V_TH. The threshold V_TH is stored as a positive magnitude for both polarities.

DC drain current (saturation + channel-length modulation):

I_D_mag   = (1/2) * mu_n * Cox * (W/L)
          * (V_GS_eff - V_TH)**2 * (1 + lam * V_DS_eff)
I_D_SPICE = pol * I_D_mag     # current INTO drain (SPICE sign)

For NMOS this is the usual positive I_D; for PMOS it is negative (the device pulls current out of the drain externally).

AC small-signal model — obtained by differentiating I_D_SPICE at (V_GS_op, V_DS_op) with sympy.diff():

g_m  = dI_D/dV_GS|_OP
g_ds = dI_D/dV_DS|_OP

Gate capacitances C_gs / C_gd are stamped as s*C admittances in AC mode. Bulk is tied to source (three-terminal).

Concrete classes NMOS_L1 and PMOS_L1 fix polarity via typing.ClassVar; users pick one in their netlist / Python API.

Classes

NMOS_L1(name, drain, gate, source, mu_n, ...)

Shichman-Hodges Level 1 NMOS (saturation region).

PMOS_L1(name, drain, gate, source, mu_n, ...)

Shichman-Hodges Level 1 PMOS (saturation region).
class sycan.components.active.mosfet_l1.NMOS_L1(name, drain, gate, source, mu_n, Cox, W, L, V_TH, lam=<factory>, C_gs=<factory>, C_gd=<factory>, V_GS_op=None, V_DS_op=None, KF=<factory>, AF=<factory>, EF=<factory>, *, include_noise=None)[source]

Bases: _MOSFET_L1

Shichman-Hodges Level 1 NMOS (saturation region).

Parameters:

  • name (str)

  • drain (str)

  • gate (str)

  • source (str)

  • mu_n (Expr)

  • Cox (Expr)

  • W (Expr)

  • L (Expr)

  • V_TH (Expr)

  • lam (Expr)

  • C_gs (Expr)

  • C_gd (Expr)

  • V_GS_op (Expr | None)

  • V_DS_op (Expr | None)

  • KF (Expr)

  • AF (Expr)

  • EF (Expr)

  • include_noise (None | str | list[str] | tuple[str, ...] | frozenset[str])

polarity: ClassVar[str] = 'N'
class sycan.components.active.mosfet_l1.PMOS_L1(name, drain, gate, source, mu_n, Cox, W, L, V_TH, lam=<factory>, C_gs=<factory>, C_gd=<factory>, V_GS_op=None, V_DS_op=None, KF=<factory>, AF=<factory>, EF=<factory>, *, include_noise=None)[source]

Bases: _MOSFET_L1

Shichman-Hodges Level 1 PMOS (saturation region).

Parameters:

  • name (str)

  • drain (str)

  • gate (str)

  • source (str)

  • mu_n (Expr)

  • Cox (Expr)

  • W (Expr)

  • L (Expr)

  • V_TH (Expr)

  • lam (Expr)

  • C_gs (Expr)

  • C_gd (Expr)

  • V_GS_op (Expr | None)

  • V_DS_op (Expr | None)

  • KF (Expr)

  • AF (Expr)

  • EF (Expr)

  • include_noise (None | str | list[str] | tuple[str, ...] | frozenset[str])

polarity: ClassVar[str] = 'P'