LV8741V Datasheet, PDF (18/24 Pages) Sanyo Semicon Device – Bi-CMOS LSI PWM Constant-Current Control Stepping Motor Driver

LV8741V
DCM Mode (DM-High)
(1) DCM mode output control logic
Parallel input
Output
DC11 (21)
DC12 (22)
OUT1 (2) A
OUT1 (2) B
Low
Low
OFF
OFF
High
Low
High
Low
Low
High
Low
High
High
High
Low
Low
Mode
Standby
CW (Forward)
CCW (Reverse)
Brake
(2) Reset function
RST
High or Low
Operating mode
Reset operation not performed
MONI
High output
The reset function does not operate in DCM mode. In addition, the MONI output is High, regardless of the RST pin
state.
(3) Output enable function
OE
Low
High
Operating mode
Output OFF
Output ON
When the OE pin is set Low, the output is forced OFF and goes to high impedance. When the OE pin is set High,
output conforms to the control logic.
(4) Current limit control time chart
Set current
Coil current
Current mode
Forced CHARGE
section
fchop
Current mode CHARGE
SLOW
(5) Current limit reference voltage setting function
ATT1
ATT2
Current setting reference voltage
Low
Low
VREF/3×100%
High
Low
VREF/3×67%
Low
High
High
High
VREF/3×50%
VREF/3×33%
The voltage input to the VREF pin can be switched to four-step settings as the reference voltage for setting the current limit.
Set current calculation method
The reference voltage is set by the voltage applied to the VREF pin and the two inputs ATT1 and ATT2. The current
limit can be set from this reference voltage and the RF resistance value.
Ilimit = (VREF/3 × Voltage setting ratio) /RF resistance
(Example) When VREF = 1.5V, setting current ratio = 100% [(ATT1, ATT2) = (Low, Low)] and RNF1 (2) = 0.5Ω,
the current limit value is as follows :
Ilimit = 1.5V/3 × 100%/0.5Ω = 1A
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