IC-GF_15 Datasheet, PDF (18/30 Pages) IC-Haus GmbH – TRANSCEIVER

iC-GF
TRANSCEIVER
DEFAULT MODE
Rev F1, Page 18/30
Enabling the switches
After power-up, the output switches remain at high
impedance for ca. 50 ms. Setting pin OEN to low un-
conditionally disables all four output switches. Other
functions of the chip (like the DC/DC converter or the
feedback channel) remain enabled.
Configuring the switches
The functionality of the switches is determined by the
pins QCFG1 and QCFG2. A voltage at QCFGx which is
lower than Va()lo (cf. Figure 8) deactivates the relevant
high-side switches; with a voltage higher than Va()hi
the relevant low-side switches are deactivated. Both
high-side and low-side switches are activated, when
the pin is left open.
CHANNEL 2
IN2 QCFG2
X
X
L
Z
H
Z
L
H
H
H
L
L
H
L
OEN
L
H
H
H
H
H
H
QN2
off
on
off
off
off
off
on
QP2
off
off
on
off
on
off
off
Table 3: Function table Channel 2 (INV1 = H, L)
Tables 2 and 3 show the switch configuration for both
channels, with respect to the input pins.
QNx active
Valo()hys
QPx active
Vahi()hys
Feedback channel CFI–CFO configuration
The feedback channel CFI–CFO polarity can be config-
ured via pin CFP (see table 4). This pin also sets the
pull-up/down current at pin CFI.
Va()lo
Va()hi
V(QCFGx)
Figure 8: Levels at QCFG1/QCFG2 for switch con-
figuration
CHANNEL 1
IN1 QCFG1
X
X
L
Z
H
Z
L
Z
H
Z
L
H
H
H
L
H
H
H
L
L
H
L
L
L
H
L
INV1
X
L
L
H
H
L
L
H
H
L
L
H
H
OEN
L
H
H
H
H
H
H
H
H
H
H
H
H
QN1
off
on
off
off
on
off
off
off
off
off
on
on
off
QP1
off
off
on
on
off
off
on
on
off
off
off
off
off
FEEDBACK CHANNEL
CFI CFP CFO PULL at CFI pin
HH Z
UP
HL L
DOWN
LH L
UP
LL Z
DOWN
Table 4: Function table Feedback Channel
Undervoltage signalling
Undervoltage at VBO, VCC or VCC3 is signalled at pin
NUVD. A valid undervoltage event is signalled at NUVD
for at least 35 ms (cf. Electrical Characteristics No. 405)
resp. as long as the duration of the undervoltage situa-
tion.
Table 2: Function table Channel 1