pulse_response
Compute step-response metrics: overshoot, undershoot, settling time, peak value, and peak time from a transient waveform. Specify signal and optional window to get precise values, with distinct handling for undefined settling times.
Instructions
Use when you need step-response quality metrics: overshoot %, undershoot %, settling time, peak value and peak time. Inputs a transient .raw covering ONE step transition — ideally with the stimulus edge near t_start and enough tail to see settling.
Returns: direction (rising/falling), initial/steady-state values, peak (absolute and pct), settling_time (to within settling_tolerance_pct band). settling_time is null in three cases, kept distinct in the text and quality flags: 'never (within window)', 'undefined (full-pulse window)', and 'unknown' when the trailing window is too noisy to trust the final value (still ringing) — pass final_value there.
Definitions: overshoot is excursion BEYOND final in the step direction; undershoot is excursion beyond initial opposite the step direction. overshoot_pct = 0 means MEASURED overdamped, not missing data. settling_tolerance_pct defaults to 2% of |final - initial|; 1% and 5% are also common.
If the auto-detected initial/final (mean of first/last 10% of window) is contaminated by ringing, pass explicit initial_value/final_value. Rejects AC analysis.
For just rise/fall time without overshoot, use edge_metrics.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| step | No | Step index for .step sweeps | |
| t_end | No | Window end in SPICE notation | |
| format | No | 'json' or 'text' | |
| job_id | No | Analyze a specific run of a completed sweep/MC (or single) job instead of a raw_file path; pair with ``run_index``. | |
| signal | Yes | Signal name (e.g. 'V(out)') | |
| t_start | No | Window start — ideally the stimulus edge. Defaults to full transient. | |
| raw_file | No | Path to .raw transient result file. Pass this OR ``job_id`` (a job run), not both. | |
| run_index | No | 0-based run to analyze when ``job_id`` is given (default 0). | |
| final_value | No | Post-step steady value. Auto = mean of last 10% of window. | |
| initial_value | No | Pre-step steady value. Auto = mean of first 10% of window. Set explicitly if the start is contaminated by ringing. | |
| settling_tolerance_pct | No | Settling band as percent of |final - initial|. 2% is standard; 1% or 5% also common. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| signal | Yes | ||
| quality | Yes | ||
| warnings | Yes | ||
| direction | Yes | ||
| peak_time | Yes | ||
| peak_value | Yes | ||
| initial_value | Yes | ||
| overshoot_pct | No | ||
| settling_time | No | ||
| undershoot_pct | No | ||
| steady_state_value | Yes | ||
| settling_tolerance_pct | Yes |