LV8747TA Datasheet, PDF (13/20 Pages) Sanyo Semicon Device – PWM Constant-Current Control Stepping Motor Driver and Switching Regulator Controller

LV8747TA
Stepping Motor Driver OUT1/OUT2(OUT3/OUT4)
(1) Output control logic
Parallel input (Note)
PS
PHA
Output
OUTA
OUTB
Current direction
Low
*
Off
Off
Standby
High
Low
Low
High
OUTB→OUTA
High
High
High
Low
OUTA→OUTB
(Note) : Enter either “H” or “L” externally for the logic input pin. Never use the input pin in the OPEN state.
(2) Constant-current setting
I0 (Note)
I1 (Note)
Output current
High
Low
High
Low
High
High
Low
Low
IO = (VREF/5) /RNF
IO = ((VREF/5) /RNF) × 2/3
IO = ((VREF/5) /RNF) × 1/3
IO = 0
(Note) : Enter either “H” or “L” externally for the logic input pin. Never use the input pin in the OPEN state.
Set current calculation method
The constant-current control setting of STM driver is determined as follows from the setting of VREF voltage, and I0
and I1, and resistor (RNF) connected between RNF and GND :
Iconst [A] = ((VREF [V] /5) /RNF [Ω]) × attenuation factor
(Example) For VREF = 1.5V, I0 = I1 = “H” and RNF = 1Ω ;
Iconst = 1.5V/5/1Ω × 1 = 0.3A
(3) Setting the chopping frequency
For constant-current control, chopping operation is made with the frequency determined by the external resistor
(connected to the CHOP pin).
The chopping frequency to be set with the resistance connected to the CHOP pin (pin 39) is as shown below.
Chopping frequency
140
120
100
80
60
40
20
0
0
10
20
30
40
50
60
70
80
CHOP resistance (kΩ)
The recommended chopping frequency ranges from 30kHz to 120kHz.
No.A2019-13/20