NCV70501 Ver la hoja de datos (PDF) - ON Semiconductor
Número de pieza
componentes Descripción
Fabricante
NCV70501 Datasheet PDF : 22 Pages
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NCV70501
In order to reduce the radiated/conducted emission,
voltage slope control is implemented in the output switches.
Two bits in SPI control register 3 allow adjustment of the
voltage slopes.
A protection against shorts on motor lines is implemented.
When excessive voltage is sensed across a MOSFET for a
time longer than the required transition time, then the
MOSFET is switched−off.
Motor Enable−Disable
The H−bridges and PWM control can be disabled
(high−impedance state) by means of a bit <MOTEN> in the
SPI control registers. <MOTEN>=0 will only disable the
drivers and will not impact the functions of NXT, DIR, RHB,
Icoil
Set value
SPI bus, etc. The H−bridges will resume normal PWM
operation by writing <MOTEN>=1 in the SPI register.
PWM current control is then enabled again and will regulate
current in both coils corresponding with the position given
by the current translator.
Automatic Forward and Slow−Fast Decay
The PWM generation is in steady−state using a
combination of forward and slow−decay. For transition to
lower current levels, fast−decay is automatically activated to
allow high−speed response. The selection of fast or slow
decay is completely transparent for the user and no
additional parameters are required for operation.
0
TPWM
Actual value
t
Forward & Slow Decay
Fast Decay & Forward
Forward & Slow Decay
Figure 5. Forward and Slow/Fast Decay PWM
PWM Duty Cycle Measurement
For both motor windings the actual PWM duty cycle is
measured and stored in two status registers. The duty cycle
values are a representation of the applied average voltage to
the motor windings to achieve and maintain the actual set
point current. Figure 6 gives an example of the duty cycle
representation.
Set value
Icoil
0
PWM
Voltage
t
PWM Value
40%
40%
40%
−48%
−38%
−40%
Figure 6. PWM Duty Cycle Measurement
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