#309 Signal Amplitude Depends on Simulation Duration in Ngspice 43 Transient Simulation Issue created by rupokdas147 Environment Ngspice 43 Qucs-s 24.3 I am encountering an unexpected behavior with Ngspice version 43 during the transient simulation. The issue is related to the amplitude of the signal, which seems to depend on the simulation duration. This problem does not occur in Ngspice version 42. Below is a detailed explanation: Input signal: A squared current source: Amplitude: 100 uA Duration of High Pulse: 20 ps Duration of Low Pulse: 20 ps Rise Time: 20 ps Fall Time: 20 ps The screenshots attached with the description were the transient simulated output of an amplifier designed using an SG132 device. Expected Behavior The expected behavior is created using Ngpice 42. With 3 ns simulation duration, The signal amplitude: image With 2 ns simulation duration, The signal amplitude: image Actual Behavior The Actual behavior is created using Ngspice 43. With a 2 ns simulation duration: The signal amplitude is very low: Screenshot_7 Witha 3 ns simulation duration: The signal amplitude is very high: Screenshot_1 Steps to Reproduce the Problem 1. Create a simple circuit that generates a square wave signal with long rise and fall times. 2. Run a transient simulation with different simulation durations (e.g., 2 ns and 3 ns). 3. Observe the output signal's amplitude. IHP-GmbH/IHP-Open-PDK