E-L6258EP STMICROELECTRONICS [STMicroelectronics], E-L6258EP Datasheet - Page 17

• Manufacturer Part Number: E-L6258EP
• Description: PWM CONTROLLED - HIGH CURRENT DMOS UNIVERSAL MOTOR DRIVER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

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
6
Figure 12. Full step operation mode timing diagram (Phase - DAC input and Motor Current)
Motor drive
Motor drive
DAC 1
Inputs
DAC 2
Inputs
Phase
Phase
Current 1
Current 2
Position
OPERATION MODE TIME DIAGRAMS
1
2
I0_1
I1_1
I2_1
I3_1
I0_2
I1_2
I2_2
I3_2
5V
5V
5V
5V
5V
5V
5V
5V
5V
0
0
0
0
0
0
0
0
0
0
0
0
0
thj-amb
1
2
.
3
0
1
2
3
0
95.2%
19.1%
95.2%
19.1%
D97IN629A
Ph2
1
2
FULL Step Vector
Ph1
Ph1
I3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
3
I2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Ph2
I1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
I0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Current level
No Current
% of I
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
100
9.5
L6258EP
MAX
17/22