
The output DMOS is ON
when the corrisponding in-
put is low
OperatingMode
The bit C5 definesthe two availableinput configu-
rations.
C5 = H: FULLMODE OPERATING
The digital inputshave the following functions:
IN1drives OUT1
IN2drives OUT2
IN3drives OUT3
IN4drives OUT4
DA/CLEVenablesthe current reduction
(seeTab 2)
DA/OPLOselectsthe motor current control
mode (openor closeloop).
Since each input drives one phase of the motor it
is possible to work either in Half Step or in Full
Step mode. DA/OPLO defines the current control
mode as follow:
– DA/OPLO= H open loop
– DA/OPLO= L closed loop
The reduced currentlevel is enabledby the inputs
IN1, IN2, IN3, IN4 or by DA/CLEV (Tab. 2). The
reduced current value depends from the bits C0,
C1 (TAB. 5). The outputs are disabled when the
inputs are in a prohibitedstate (Tab. 4).
C5 = L, SIMPLIFIEDMODE OPERATING
When in SIMPLIFIEDMODE OPERATING the in-
puts assumethe followingfunctions:
IN1 drivesPhase A
IN2 drivesPhase B
IN3 ENABLEinput (activeHigh)
IN4 enables the reduced current (Tab. 3)
DA/CLEVenables the reduced current (Tab.3)
DA/OPLO selects the motor current control
mode
The SIMPLIFIED MODE OPERATING configura-
tion does not allow the drive of a unipolar motor in
Half step.
The signal DA/OPLO functions as in FULL Mode
Operation. When the current control is imple-
mented in closed loop, the reduced current level
is enabled by the inputs IN4, DA/CLEV (Tab. 3).
The current reduction depends from the bits C0,
C1 (Tab. 5).
Open/Closed LoopMotor Current Control
The logic input DA/OPLO selects the current con-
trol mode as previously seen. When in open loop,
the chopping frequency is that one as defined by
the external RC network. In open loop are avail-
able three different t(ON), dependingfrom the bits
C2, C3 (Tab. 6), as a percentage of the RC dis-
chargetime t
(dis)
.
When in closed loop two different chopping fre-
quencies are selectable by means of the bit C4
(Tab. 7). The higher is defined by the external RC
network. The other one is exactely the half. In
closed loop 5 different current levels are avail-
able: the nominal current level and four reduced
current levels (Tab. 5). The nominal current level
is set by an internal reference voltage of 0.5V.
The configuration of bits C0, C1 sets the refer-
ence voltage to a pecentageof thenominal value.
TRUTH TABLES
(L = Low; H = High; X = don’t
care)
Table 2
IN1
IN2
IN3
IN4
DA/CLEV
C/R*
H
H
X
X
X
H
X
X
H
H
X
H
H
H
H
H
X
H
X
X
X
X
H
H
*) C/R = H, reduced current
Table 3
IN4
DA/CLEV
C/R
L
X
H*
X
H
H*
H
L
L**
*) Reducedcurrent **) Nominal current
Table 4
IN1
IN2
IN3
IN4
Output Stage
L
L
X
X
DISABLED
X
X
L
L
DISABLED
Table 5
C0
C1
Reduced Current Level (*)
L
L
40%
L
H
50%
H
L
70%
H
H
85%
*) Nominallevel percentage
L6223
10/33