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Data Sheet

ManualsBrandsPololu ManualsStepper Motor ControllersPololu TB67S279FTG Stepper Motor Driver Carrier (1.2 A continuous)
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TB67S279FTG
2017-09-15
16
Constant current threshold calculation
The constant current PWM threshold can be set by applying voltage to the VREF pin.
IOUT=VREF × 0.556
Example: When Current Ratio is 100 % and VREF voltage is 2.0 V, the constant current PWM threshold is calculated from
following formula.
IOUT = 2.0 × 0.556=1.11 A
ADMD current waveform
• When the next current step/ratio is higher than the previous step
• When the Charge period continues beyond 1 fchop cycle
Timing charts may be simplified for explanatory purpose.
NFth
Slow
Slow
Slow
Slow
Fast
Fast
Charge
Charge
Fast
Charge
Fast
Charge
NF
NF
NF
NF
Internal
OSC
waveform
fchop
fchop
fchop
fchop
Slow
Slow
Slow
Fast
Fast
Charge
Charge
Fast
Charge
NF
NF
NF
fchop
fchop
fchop
fchop
Charge sequence continues until
the motor current reaches the NF
threshold.
NFth
ADMDth
ADMDth
NFth
ADMDth
Internal
OSC
waveform
NFth
ADMDth