L6258EP Datasheet, PDF (17/22 Pages) STMicroelectronics – PWM CONTROLLED - HIGH CURRENT DMOS UNIVERSAL MOTOR DRIVER

L6258EP
5.2 Motor Selection
Some stepper motor have such high core losses that they are not suitable for switch mode current regulation. Fur-
thermore, some stepper motors are not designed for continuous operating at maximum current. Since the circuit
can drive a constant current through the motor, its temperature might exceed, both at low and high speed operation.
5.3 Unused Inputs
Unused inputs should be connected to the proper voltage levels in order to get the highest noise immunity.
5.4 Notes on PCB Design
We recommend to observe the following layout rules to avoid application problems with ground and anomalous
recirculation current.
The by-pass capacitors for the power and logic supply must be kept as near as possible to the IC.
It's important to separate on the PCB board the logic and power grounds and the internal charge pump circuit
ground avoiding that ground traces of the logic signals cross the ground traces of the power signals.
Because the IC uses the board as a heat sink, the dissipating copper area must be sized in accordance with the
required value of R_thj-amb.
6 OPERATION MODE TIME DIAGRAMS
Figure 12. Full step operation mode timing diagram (Phase - DAC input and Motor Current)
Position
0
1
2
3
0
1
2
3
0
5V
Phase
1
0
FULL Step Vector
Ph1
5V
Phase
2
0
1
0
5V
I0_1
0
Ph2
Ph2
5V
I1_1
DAC 1
0
Inputs
5V
I2_1
0
5V
I3_1
0
5V
I0_2
DAC 2
0
Inputs
5V
I1_2
0
5V
I2_2
0
2
3
Ph1
I3
I2
I1
I0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
I3_2
0
0
1
1
0
0
1
1
1
Motor drive
Current 1 0
95.2%
19.1%
1
0
0
0
1
0
0
1
1
0
1
0
Motor drive
Current 2 0
95.2%
19.1%
1
0
1
1
1
1
0
0
1
1
0
1
D97IN629A
1
1
1
0
1
1
1
1
Current level
% of I_MAX
100
98.4
95.2
92.1
88.9
82.5
77.8
71.4
63.5
55.6
47.6
38.1
28.6
19.1
9.5
No Current
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