AnsweredAssumed Answered

L6472 / L6474

Question asked by hoffmann.burghard on Aug 27, 2013
Latest reply on Sep 26, 2014 by cook.brett
I am experiencing problem with the current regulation of the L6472. We made 2 series of boards, one was fitted with L6474s, the other one with L6472s. The board has 8 channels, supply voltage is 24V / 3.3V, timing parameters are reset default, internal oscillator. The motor windings have 1.7Ohm, 3.6mH. The board has 4 layers of 35µm including solid planes for 24V and GND. Everything is fine for the L6474. With the L6472 the phase current jumps wildly close to the zero crossing of the microstep sequence. All channels are affected, but usually only one phase of each channel. No difference between predictive and peak current regulation. I have several ideas what could be wrong:
1) Current measurement influenced by some ground shift effect
2) Supply voltage too noisy
3) Suboptimal timing parameters

I am wondering where to look first.