Power-Delivery Network (PDN) Simulator

Model whether a power rail stays inside its voltage margin — then run it: the simulation executes on the ChipFoundryServices distributed compute pool. Two droops eat the margin. Static IR-drop is the resistive loss ΔV = I·R across the PDN. The transient L·di/dt droop appears when a current step ΔI hits the package inductance and it rings against the on-die decoupling capacitance; the anti-resonance peak impedance is Zpeak = L / (R·C) at fres = 1 / (2π√(LC)). There is a PDN-resistance sweet spot: too little R lets the tank ring, too much piles on IR-drop, so total droop has a minimum near R* = √(ΔI·L / (I·C)). The node returns the static and transient droop, the minimum supply voltage Vmin, the peak impedance and resonant frequency, and checks the total against the voltage-margin budget and the classic target-impedance criterion Ztarget = ΔV / ΔI — sweeping decap to expose the droop-vs-decap knee. Reduced-order educational model. See also the place-and-route, device reliability, transistor I-V, power & thermal, thermal, interconnect RC/EM, 6T SRAM, die-yield, 3D-parallelism, HBM bandwidth, systolic array, CMP planarization and lithography simulators and the compute-pool status.

Datacenter CPU rail GPU · high-current Marginal PDN
Total supply droop vs decoupling capacitance (log axis). Total droop (green) falls as decap is added and asymptotes to the static IR-drop floor (blue dashed); the transient component (orange) is what the decap actually suppresses. The rail fails once droop crosses the dashed red voltage-margin budget; the marker (●) is your current decap
Left: PDN impedance |Z(f)| (log-log) — the decap and package inductance form an anti-resonance peak at fres; the rail is safe when the peak stays under the dashed target impedance Ztarget = ΔV/ΔI. Right: the droop budget — static IR-drop and transient di/dt droop as a share of the voltage margin (100 % = margin violation)
Developer API — same simulation over HTTP (load-balanced across the pool): 
curl -X POST https://www.chipfoundryservices.com/edge/pdn \
  -H "Content-Type: application/json" \
  -d '{"vdd_mv":800,"current_a":120,"pdn_resistance_mohm":0.2,
       "pdn_inductance_ph":8,"decap_uf":80,"di_dt_percent":50,
       "transition_ns":0.5,"voltage_margin_mv":60}'
Returns JSON with outputs (ir_drop_mv, transient_droop_mv, total_droop_mv, droop_percent, vmin_mv, margin_mv, meets_margin, z0_mohm, z_peak_mohm, q_factor, damping_zeta, f_res_mhz, target_impedance_mohm, meets_z_target, decap_needed_uf, edge_factor, current_step_a, dominant_component, verdict), the full profile (48-point droop_vs_decap sweep [decap_uf, total_droop_mv, transient_droop_mv] and 64-point impedance_vs_freq sweep [freq_hz, z_mohm], plus z_target_mohm, budget_mv, decap_uf, current_droop_mv, f_res_mhz), the serving node, and compute_ms. Endpoint aliases /edge/irdrop, /edge/droop, /edge/ldidt, /edge/voltagedrop, /edge/powerintegrity, /edge/supplydroop.