IC-HF Datasheet, PDF (16/36 Pages) IC-Haus GmbH – 6-CH. ENCODER LINK, RS-422 DRIVER/RECEIVER

iC-HF
preliminary
6-CH. ENCODER LINK, RS-422 DRIVER/RECEIVER
INTERNAL PROTECTION AND ERROR SIGNALING
Rev C1, Page 16/36
iC-HF is protected against internal overtemperature.
When internal temperature is higher than a safety value
(cf. Electrical Characteristics no. 005), an overtemper-
ature event (OVT) is triggered and all output stages
are set to high impedance though internal signal ”TRI”.
Output stages are also left in high impedance if a pow-
er-down (PoDo) event is detected.
When the channel outputs are in high impedance, this
is signaled through output pin NERR. NERR is an
open-drain output and it goes lo when an overtempera-
ture or power-down event is triggered, when OEN is lo,
or when NERRI input is set lo.
The logic state of signal at input pin NERRI is directly
passed to NERR output. This allows transferring an
error signal from the sensor through iC-HF. If not used,
NERRI should always be set hi.
Figure 18 shows an example of using NERRI pin
for combining the external NERRI input signal from
iC-MH with the iC-HF internal OVT and PoDo error
signals to NERR output. In this example, iC-HF is in
A/B/Z and U/V/W mode, operating as a set of 6 line
drivers.
The open drain NERR output is protected against ex-
ternal short circuit. An error LED can be driven directly
and used for visual warning or the NERR signal can be
connected to a microcontroller interrupt pin.
INCR INTERFACE
SERIAL
INTERFACE
RS422
VPD
VPA
A
B
Z
U
V
W
MA
SLO
SLI
ERROR MONITOR
NERR
VND
VNA
iC-MH
VDDS
1 μF
GNDS
VDD
4.5..5.5V
REVERSE POLARITY PROTECTION GND
1 μF
X1
NX1
X2
NX2
X3
NX3
X4
X5
X6
PTC
ECM
OEN
FMSEL1
FMSEL2
NERRI
BYP EBIS TRI
CONTROL
LOGIC
OVT
PoDo
1
Q1
TRI
NQ1
Q2
RS422 output
NQ2
Q3
RS422 output
NQ3
Q4
RS422 output
NQ4
Q5
RS422 output
NQ5
Q6
RS422 output
NQ6
BYPR
ENCODER LINK
REQUEST
DETECTION
OVT
PoDo
OVERTEMP
POWER DOWN
Q1
NQ1
NERR
iC-HF
A
B
Z
U
V
W
to mC
NERR
Figure 18: NERR signaling example in A/B/Z and U/V/W mode