Three current waveforms

Compare rising sawtooth, falling sawtooth, and triangle currents at 1 kHz, each swinging from −5 mA to +5 mA. The stacked charts show three complete cycles in the same order as the schematic.

Common settings

All three branches use the Triangle Current Source with a 1 kΩ load. Each source has a 10 mA amplitude, −5 mA offset, 1 ms period, and zero delay. Double-click a source to edit these settings.

Amplitude is the swing above the offset: −5 mA + 10 mA = +5 mA. Each load therefore has a voltage swing of −5 V to +5 V relative to ground.

Read the charts

Source	Waveform	Fall time
I1 · blue	Rising sawtooth	1 µs
I2 · purple	Falling sawtooth	999 µs
I3 · orange	Triangle	500 µs

• Rising sawtooth: rises for 999 µs, then resets in 1 µs.
• Falling sawtooth: rises in 1 µs, then falls for 999 µs.
• Triangle: rises for 500 µs and falls for 500 µs.

The probes measure current toward the loads. Positive current leaves the upper source terminal and flows downward through the resistor. Negative current flows in the opposite direction.

Try it

Set I1 or I2's Fall time to 500 µs and run the simulation; its trace should match the triangle. Keep fall time greater than zero and less than the period.

The transient runs from 0 to 3 ms with a maximum time step of 500 ns to resolve the finite sawtooth resets.