NJM3517
DIR
H
L
DIR
INT
L
L
INH
HSM
STEP
H
P
HSM
STEP
H
P
OB
L
P
P
P
P
P
P
L
OB
LB
L
LB
P
P
P
P
P
P
L
PB1
PB2
PA1
PA2
LA
PB1
PB2
PA1
PA2
LA
OA
OA
Figure 7. Full-step mode, forward. 4-step sequence. Gray-code
Figure 8. Full-step mode, reverse. 4-step sequence. Gray-
+90° phase shift.
code -90° phase shift.
DIR
L
L
L
P
DIR
H
L
INH
INH
HSM
STEP
HSM
STEP
L
P
C
C
OB
P
P
P
P
P
P
P
P
OB
P
P
P
P
P
P
P
P
LB
LB
PB1
PB2
PA1
PA2
LA
PB1
PB2
PA1
PA2
LA
OA
OA
Figure 9. Half-step mode, forward. 8-step sequence.
Figure 10. Half-step mode, reverse. 8-step sequence.
DIR
L
H
L
INH
HSM
STEP
P
C
OB
P
P
H
H
H
H
P
P
LB
PB1
PB2
PA1
PA2
LA
OA
Figure 11. Half-step mode, inhibit.
■ APPLICATIONS INFORMATION
Logic inputs
If any of the logic inputs are left open, the circuit will treat it as a high-level input. Unused inputs should be con-
nected to proper voltage levels in order to get the highest noise immunity.
Phase outputs
Phase outputs use a current-sinking method to drive the windings in a unipolar way. A common resistor in the
center tap will limit the maximum motor current.
Fast free-wheeling diodes must be used to protect output transistors from inductive spikes.
Series diodes in V supply, prevent VSS voltage from shorting through the VMM power supply. However, these
may be omitted if noMbMi-level is used. The VSS pin must not be connected to a lower voltage than VMM, but can be left
unconnected.
Zero outputs
Ø and Ø , “zero A” and “zero B,” are open-collector outputs, which go high when the corresponding phase output
isAinhibiteBd by the half-step-mode circuitry. A pull-up resistor should be used and connected to a suitable supply
voltage (5 kohms for 5V logic). See “Bipolar phase logic output.”
Interference
To avoid interference problems, a good idea is to route separate ground leads to each power supply, where the
only common point is at the NJM3517’s GND pin. Decoupling of VSS and VMM will improve performance. A 5 kohm
pull-up resistor at logic inputs will improve level definitions, especially when driven by open-collector outputs.
NJRC [ NEW JAPAN RADIO ]
