amis-30523 ON Semiconductor, amis-30523 Datasheet - Page 25

• Manufacturer Part Number: amis-30523
• Description: Amis-30523 Product Preview Can Micro-stepping Motor Driver
• Manufacturer: ON Semiconductor

Note: Successive reading the SPI StatusRegisters 1 and 2 in
case of a short circuit condition, may lead to damage to the
drivers
Open Coil/Current Not Reached Detection
duty cycle of the PWM regulator. If in a coil 100% duty cycle
is detected for longer than 200 ms then the related driver
transistors are disabled (high−impedance) and an
appropriate bit in the SPI status register is set (<OPENX> or
<OPENY>). (Table 17 SPI Status Register Address SR0)
supply voltage is low, it can happen that the motor driver is
not able to deliver the requested current to the motor. Under
these conditions the PWM controller duty cycle will be
100% and after 200 ms the error pin and <OPENX>,
<OPENY> will flag this situation (motor current is kept
alive). This feature can be used to test if the operating
conditions (supply voltage, motor coil resistance) still allow
reaching the requested coil−current or else the coil current
should be reduced.
Charge Pump Failure
low R
voltages. If supply voltage is too low or external components
are not properly connected to guarantee R
drivers, then the bit <CPFAIL> is set in Table 17. Also after
POR the charge pump voltage will need some time to exceed
Open coil detection is based on the observation of 100%
When the resistance of a motor coil is very large and the
The charge pump is an important circuit that guarantees
DS(on)
for all drivers, especially for low supply
V
V
DDH
DDL
VDD
VBB
POR/WD pin
Figure 22. Power−on−Reset Timing Diagram
DS(on)
t
PU
http://onsemi.com
of the
t
POR
25
the required threshold. During that time t
will be set to “1”.
Error Output
microcontroller. The signal on this output is active low and
the logic combination of:
NOT(ERRB) = <TW> OR <TSD> OR <OVCXij> OR
< OVCYij> OR <OPENi> OR <CPFAIL>
This open drain output can be wired OR−ed with error
outputs other motor drivers.
Logic Supply Regulator
with external capacitor to supply the digital part of the chip,
some low−voltage analog blocks and external circuitry. The
voltage level is derived from an internal bandgap reference.
To calculate the available drive−current for external
circuitry, the specified I
consumption of internal circuitry (unloaded outputs) and the
loads connected to logic outputs. See Table 5 DC parameters
Motor Driver.
Power−On Reset (POR) Function
low” reset for external purposes. At power−up of
AMIS−30523, this pin will be kept low for some time to reset
for example an external microcontroller. A small analogue
filter avoids resetting due to spikes or noise on the V
supply.
< t
This is a digital output to flag a problem to the external
AMIS−30523 has an on−chip 5 V low−drop regulator
The open drain output pin PORB/WD provides an “active
RF
t
PD
t
RF
load
should be reduced with the
t
t
CPU
<CPFAIL>
DD