AMG-XB404 Datasheet, PDF (26/73 Pages) alpha microelectronics gmbh – Fully Integrated Single Motor Controller for Electrical Motors

AMG-XB404
Fully Integrated Single Motor Controller for Electrical Motors
5.4.5. Power Stage Over-Current Protection
OFI
0.5V
trip level
XOR
IFOP
IFOERR
CNT
R
f
IFORES
MCU
EN
&
XOR
MO1
DMCE
UHi
VHi
PWM
WHi
ULi
VLi
WLi
XOR
POL
MO6
Figure 14: Over-current protection block schematic
In the event of over-current a dedicated hardware unit for the DMCE will turn off all logic outputs,
indicate this error via a dedicated IO expander flag (see section5.2.16., p.12), and optionally trigger
the shared DMCE/PFC interrupt of the MCU.
If the power stage connected to the AMG-XB404 provides a digital over-current fault indicator (OFI)
input, the OFI input acts as a digital input with a logic threshold level of 0.5V nominally.
If no digital over-current fault indicator flag is available, the OFI input acts as an analog comparator
with a trip level of 0.5V nominally, which is the standard power stage module trip level. In this case
the shunt resistor connected to the power stage needs to be dimensioned accordingly.
The AMG-XB404 can handle power stage modules having any combination of driver and over-
current feedback polarity, see Figure 14 above. As described in section 5.2, p. 9 five dedicated
signals control the polarity of drivers and over-current fault input, error indication and reset, and
enabling of the driver outputs.
The over-current fault input signal OFI is low-pass filtered digitally, it needs to continually indicate
an error for at least 1µs nominally to detect an over-current condition.
The pin order of the driver and high voltage feed-back pins can be configured freely as described
in section 5.2.13., p. 11.
AMG-XB404
Revision: A
2. Nov. 2012 © All rights reserved
Page 26 of 73