pbl3717as STMicroelectronics, pbl3717as Datasheet - Page 8

• Manufacturer Part Number: pbl3717as
• Description: Stepper Motor Driver
• Manufacturer: STMicroelectronics

PBL3717A
Quarter Step Operation
It is preferable to realize the quarter step operation
at full power otherwise the steps will be of very ir-
regular size.
The extra quarter steps are added to the half steps
sequence by putting one coil on half current accord-
ing to the sequence.
Motor Selection
As the PBL3717A provides constant current drive,
with a switching operation, care must be taken to se-
lect stepper motors with low hysteresis losses to
prevent motor over heat.
Figure 6 :
Figure 8 :
8/11
AB
A
2
B
Source Saturation Voltage versus
Output Current (recircuit period)
Sink Saturation Voltage versus
Output Current
B
A
2
B
AB
A
B
2
A etc.
L -C Filter
To reduce EMI and chopping losses in the motor a
low pass L -C filter can be inserted across the out-
puts of the PBL3717A as shown on the following pic-
ture.
Figure 7 :
Figure 9 :
L
Source Saturation Voltage versus
Output Current (conduction period)
Comparator Threshold versus
Junction Temperature
10
1
LM
C
4 10
L
10