LM334 with soft start 01 PUBLIC

A way to implement "soft switching" between different currents using the LM334 3-Terminal Adjustable Current Source.

A way to implement "soft switching" between different currents using the LM334 3-Terminal Adjustable Current Source.

This is based on the behavioural model of the LM334 but should work OK with the real device.

The current switching rise/fall time Ts = L1/Rset_tot

where Rset_tot = the total resistance switched in for each current setting. For a fixed time constant, omit L1 and instead, put a separate inductor in series with each current setting resistor. Select the value of each L so that:

Lset/Rset = Ts_des

where Ts_des = the desired time constant.

Note supply startup and 1kHz ripple in Vsupply1 using behavioural source expression.

This behavioural LM334 is ideal. The real device would not reject the supply ripple perfectly the way this one does.

F5 to simulate.