IC-DX_11 Datasheet, PDF (6/10 Pages) IC-Haus GmbH – UNIVERSAL DIGITAL SENSOR OUTPUT DRIVER

iC-DX
preliminary
UNIVERSAL DIGITAL SENSOR OUTPUT DRIVER
DESCRIPTION OF FUNCTIONS
Rev A3, Page 6/10
iC-DX is a current limited switching channel which
enables digital sensors to drive peripheral elements.
They are designed to cope with high driver currents.
The switches are reverse-polarity protected, feature a
free-wheeling circuit for inductive loads, and a current
limited output.
Reverse polarity protection
The pins VB, OUT an GND on the line side of the chip
are reverse polarity protected. As far as the maximum
voltage ratings are not exceeded, no possible supply
combination at the line side pins can damage the chip.
I(OUT)
Output characteristics of OUT
The switching channel is current limited to a value be-
tween 150mA and 450mA. (cf. Electrical Characteris-
tics Nos. 103, 104). The current limitation works only
for voltages higher than 3 V at OUT resp. lower than
VBO − 3 V. For smaller output voltages the current lim-
itation is reduced in order to minimise the saturation
voltages without increasing the power dissipation. Fig-
ures 1 and 2 show the characteristic of the switching
channels when activated. Region "A" is the saturation
range, where the current limitation is not fully active yet
and region "B" is the current limited range. Region "C"
corresponds to the free-wheeling circuit activated. The
switching channel is designed so that the low side can
only sink current and high side can only source current
(no reverse current).
Isc()lo
GND
3V
A
VB
B
36V
V(OUT)
C
Figure 1: OUT characteristic when Low side active
Free-wheeling circuit for inductive loads
The free-wheeling circuit is always present and does
not depend on the current output status. It is acti-
vated by voltages higher than 36 V at OUT referenced
to GND or lower than -36 V at OUT referenced to VB.
In that case the correspondent channel will switch on
without current limitation (see Figure 3).
VB-36V
C
I(OUT)
GND B
Isc()hi
A VB V(OUT)
VB-36V
I(OUT)
36V
GND
VB
V(OUT)
GND+36V
36V
36V
Figure 2: OUT characteristic when high side active
Figure 3: Free-wheeling characteristic