IC-HF Datasheet, PDF (21/36 Pages) IC-Haus GmbH – 6-CH. ENCODER LINK, RS-422 DRIVER/RECEIVER

iC-HF
preliminary
6-CH. ENCODER LINK, RS-422 DRIVER/RECEIVER
Rev C1, Page 21/36
iC-PTxxyy/ iC-PT-Hxxyy mode control
iC-HF is a general purpose 6-channel line driver. iC-HF
is suitable to be operated with iC-PTxxyy and iC-P-
T-Hxxyy opto encoder.
VCC
iC-PTxxyy
SEL
GND
VDDS
R1
iC-HF
PTC
R2
GNDS
Figure 23: iC-PTxxyy and iC-HF connection for Ana-
log Mode selection.
If iC-PTxxyy input pin SEL is lo, A/B mode is selected
and iC-PTxxyy delivers complementary digital A/B/Z
signals. If iC-PTxxyy input pin SEL is hi, iC-PTxxyy is in
A/B mode with two fold interpolation. When iC-HF en-
ters Encoder Link State output pin PTC provides VDD/2
to iC-PTxxyy and therefore iC-PTxxyy is forced to enter
analog mode. In this analog mode, analog signals from
the photosensors are directly output.
SEL
R1¹⁾ R2¹⁾
100 % VCC 10 kΩ open
50 % VCC open open
0 % VCC open 10 kΩ
1) Exemplary values.
Operation Mode
ABZ x2 interpolated
all analog
x1 interpolated
Table 7: Selection of iC-PTxxyy operation mode by pin
SEL.
In order to improve the noise rejection and stability at
pin PTC, an external 10nF capacitor C_PTC can be added
between PTC and GNDS pins.
External pull-up and pull-down resistors at SEL pin can
be used in order to select the iC-PTxxyy working mode.
iC-HF output PTC pin is used to control the iC-PTxxyy
to output analog signals. When Encoder Link mode is
entered, PTC delivers VDD/2 voltage. If connected to
SEL pin from iC-PTxxyy, this will enter analog mode
and signals from the photosensors will be present at
output pins Qi/NQi from iC-HF.
Figure 23 shows how to connect iC-PTxxyy and iC-HF
in order to force Analog Mode in iC-PTxxyy when iC-HF
enters Encoder Link. The recommended resistor values
are given in table 7. See page 24 for more information
on driving an iC-PTxxyy with iC-HF.
iC-PT-Hxxyy opto encoder include 3 additional working
modes. Table 8 gives the recommended resistor values
for fixing any working mode and allowing All Analog
mode when iC-HF enters Encoder Link.
SEL
R1¹⁾ R2¹⁾
100 % VCC 2.7 kΩ open
75 % VCC 12 kΩ 48 kΩ
50 % VCC open open
25 % VCC 48 kΩ 12 kΩ
0 % VCC open 2.7 kΩ
1) Exemplary values.
Operation Mode
x2 interpolated
analog ABZ, dig. UVW
all analog
x4 interpolated
x1 interpolated
Table 8: Selection of iC-PT-Hxxyy operation mode by
pin SEL.