Tool/software:
Hello,
I’m using the MCT8329A and I want to manually control the open-loop → closed-loop handoff speed. I do not want to use AUTO_HANDOFF; instead, I want to set a fixed handoff threshold (in Hz/RPM) that works unchanged across the full supply range 12 V to 32 V.
Problem summary
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At 12 V, the motor only transitions to closed-loop if OL_DUTY = 30%.
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At 28 V, the same motor transitions only if I reduce OL_DUTY to = 10%.
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With a single, fixed OL_DUTY value, the handoff fails at one end of the PVDD range.
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My motor does not behave well with the integration method; the calculated integration thresholds are very high and exceed the GUI range. So I prefer ZC-only (or at most hybrid, but integration is not ideal here).
Goal
A single parameter set (no AUTO_HANDOFF) that guarantees reliable manual handoff at the same commanded RPM/Hz and OL_DUTY from 12 V up to 32 V.
Motor / setup details
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Max speed: 7000 rpm
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Desired manual handoff speed: 1000 rpm
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Topology: Sensorless BLDC, trapezoidal / 120° commutation
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Supply range: 12–32 V
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Pole pairs: 2
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PWM frequency: 20000
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Control mode during open-loop: Voltage (duty)
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Shunt Rs and CSA gain: 1m & 40
