iC-JX
16-FOLD 24 V HIGH-SIDE DRIVER WITH µC INTERFACE
Rev C1, Page 32/36
RSET settings
pull-up or pull down.
iC-JX can either generate an internal reference current
or permit external current settings via pin RSET. Set-
ting the current externally is the more precise option
here; to this end it is recommended that pin RSET be
linked up to a 10 kΩ resistor connected to ground..
ADC measurements
ADC measurements: measuring current (Adr.
0x1C)
In this mode the current in each output stage can be
measured. Here, the saturation voltage from an inter-
nal reference transistor is used for comparison. Each
I/O stages in input mode funktion
Input registers (add. 0x00 and 0x01: reading the in- output stage has its own reference transistor in order
puts to guarantee a precise value. The reference voltage is
A high at IOx generates a high signal at bit INx. Any equivalent to the saturation voltage of the output stage
change to an input signal is accepted via digital filter- transistor with a nominal current of 150 mA; the output
ing only after the selected filter time has expired. Here, digital value thus corresponds to the current intensity
the input comparator of each I/O stage reverses the in the output stage.
count direction of a 3-bit counter. The counter output
changes only when the final status has been reached.
The counters are reset to a value of 3 by a low signal
at reset input NRES. The counter is clocked externally
by pin CLK or by clock ICLK, generated internally.
To evaluate current variations in the output stage the
controller must perform an initial measurement with a
known reference current. Based on this value a moni-
toring of the load current can then be performed. The
output stage thereby is selected via SELES(3:0) in
The scaling factor for the clock frequency and the in- control word 5 (Adr. 0x1B).
put filter bypass can be programmed separately for all
four nibbles (see control word 1, addresses 0x14 and
0x15). Switching the bypass (BYP1...4) permits oper-
ation without an external clock signal (see below).
ADC measurements: measuring voltage (Adr.
0x1C)
iC-JX enables voltage at the I/O stage to be recorded.
The range for voltage measured at the output stage
Once the change-of-input message has been enabled lies between VB - 5 V and VB (bit EME = 1) and be-
in the change-of-input interrupt enable register (ad- tween VB - 0.6 V and VB (EME = 0). When measuring
dresses 0x10 and 0x11) a change of level at one of in conjunction with pull-up current sources the range
the I/O pins is signaled to the microcontroller. If iC- lies between 0 V and 5 V (EME = 1) and between 0 V
JX is operated at the parallel interface the level at pin and 0.6 V (EME = 0).
NINT is set to 0. If the device is operated at the serial
interface a change of level is indicated by a 0 at pin
SO(D1) resp SOB (D2), depending upon configuration
(see SPI interfacd, page 26). The microcontroller can
VIO
36V max.
determine which I/O stage has had a change of input
by reading out the input register.
VBy
0.6V
VR5
VR1
VR3
5V
5V
VR2
VR4
I/O stages in output mode
Input registers (addresses 0x00 and 0x01): reading
the output feedback
A high at IOx generates a high signal at INx. This al-
lows the microcontroller to make a direct check of the
switching state and, with the help of the programmable
high-side current sources of 200 µA, 600 µA and 2 mA,
to monitor the channel for any cable fractures. As
with the reading of inputs the feedback signals can be
output in their filtered or unfiltered state. The micro-
controller can determine which I/O stage has had a
change of input by reading out the input register.
0.6V
0
Figure 15: ADC measurement ranges
The iC-JX measures voltages at the I/O stages in dif-
ferent ranges. The range "Voltage Measurement High
at IO" is between VB – 5 V and VB (Bit EME = 1)
Programmable Current Sources
(Adr. 0x16 und 0x17)
The programmable pull-up- resp. pull-down current resp. between VB – 0.6 V and VB (EME = 0). In the
sources can be set independently of the I/O mode (ei- mode "Voltage Measurement Low at IO" the range is
ther input or output mode). In both modes current val- between 0 and 5 V (Bit EME = 1) resp. between 0 and
ues of 200 µA, 600 µA or 2 mA are available either as 0.6 V and VB (EME = 0).
ICHAUS [ IC-HAUS GMBH ]
