L6228 Application information
A typical bipolar stepper motor driver application using the L6228 device is shown in
Figure 25
. Typical component values for the application are shown in Table 7 . A high quality
ceramic capacitor in the range of 100 to 200 nF should be placed between the power pins
(VS
A
and VS
B
) and ground near the L6228 device to improve the high frequency filtering on the power supply and reduce high frequency transients generated by the switching. The capacitor connected from the EN input to ground sets the shutdown time when an overcurrent is detected (see
Section 7.5: Non-dissipative overcurrent protection on page 21 ). The two current sensing inputs (SENSE
A
and SENSE
B
) should be connected to the sensing resistors with a trace length as short as possible in the layout. The sense resistors should be non-inductive resistors to minimize the di/dt transients across the resistor. To increase noise immunity, unused logic pins (except EN) are best connected to
5 V (high logic level) or GND (low logic level) (see
Table 4: Pin description on page 6 ). It is
recommended to keep power ground and signal ground separated on the PCB.
Component
C
1
C
2
C
A
C
B
C
BOOT
C
P
C
EN
C
REF
Table 7. Component values for typical application
Value Component
100 µF
100 nF
1 nF
1 nF
220 nF
10 nF
5.6 nF
68 nF
D
1
D
2
R
A
R
B
R
EN
R
P
R
SENSEA
R
SENSEB
Value
1N4148
1N4148
39 K
39 K
100 K
100
0.6
0.6
DocID9454 Rev 3 25/34
34
