MOTOR DRIVING PHASE SEQUENCES

The L297’s translator generates phase sequences

for normal drive, wave drive and half step modes.

The state sequences and output waveforms for

these three modes are shown below. In all cases

the translator advances on the low to high transis-

tion of CLOCK.

Clockwise rotation is indicate; for anticlockwise ro-

tation the sequences are simply reversed RESET

restores the translator to state 1, where ABCD =

0101.

HALF STEP MODE

Half step mode is selected by a high level on the HALF/FULL input.

NORMAL DRIVE MODE

Normal drive mode (also called "two-phase-on" drive) is selected by a low level on the HALF/FULL input

when the translator is at an odd numbered state (1, 3, 5 or 7). In this mode the INH1 and INH2 outputs

remain high throughout.

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L297