GS-D200S SGS-Thomson-Microelectronics, GS-D200S Datasheet - Page 8

• Manufacturer Part Number: GS-D200S
• Description: 2 / 2.5 A BIPOLAR STEPPER MOTOR DRIVE MODULE
• Manufacturer: SGS-Thomson-Microelectronics

GS-D200/GS-D200S
PHASE SEQUENCE GENERATION INSIDE THE
GS-D200/GS-D200S
The modules contains a three bit counter plus
some combinational logic which generate suitable
phase sequences for half step, wave and normal
full step drive. This 3 bit counter generates a basic
eight-step Gray code master sequence as shown
in fig. 9. To select this sequence, that corresponds
to half step mode, the HALF/FULL input (pin 4)
must be kept high or unconnected.
The full step mode (normal and wave drive) are
both obtained from the eight step master sequence
by skipping alternate states. This is achieved by
Figure 9: The Eight Step Master Sequence corresponding to Half Step Mode.
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forcing the step clock to bypass the first stage of
the 3 bit counter. The least significant bit of this
counter is not affected and therefore the generated
sequence depends on the state of the counter
when full step mode is selected by forcing pin 4
(HALF/FULL) low. If full step is selected when the
counter is at any odd-numbered state, the two-
phase-on (normal mode) is implemented (see fig.
10).
On the contrary, if the full mode is selected when
the counter is at an even-numbered state, the
one-phase-on (wave drive) is implemented (see
fig. 11).