iC-NE
LIGHT-GRID PULSE RECEIVER
Rev E1, Page 7/9
APPLICATIONS INFORMATION
Signal Processing
Figures 6 and 7 show output signal I(SP)
−
I(SN) in
normal
drive and in extreme overdrive (with the photo-
diode and input amplifier in saturation).
extreme overdrive, which yields definite results. Eval-
uating the falling edge of the output signal or the level
of the negative output signal half-wave (the recovery
process at the end of a light pulse) is generally not ad-
vised.
Figure 6: Regular input signals
Figure 7: Excessive input signals
It is clear from these diagrams that iC-NE, even when
in overdrive, is not
blind
to a follow-on pulse. For eval-
uation purpose the response to the rising edge of the
light pulse (i.e. the rising edge of the output signal) is
to be used as it is this edge alone, even in the most
CLK
+5V
Light curtain
The circuit in Figure 8 shows iC-NE chained up to form
a light curtain, where consecutive PIN diodes receive
and evaluate clock-driven light pulses.
IC1
CONTROL
LOGIC
DIN1
1
DIN
PD
8
PD1
1
IC2
C
CONTROL
LOGIC
DIN
PD
8
PD2
GROUP
1
ICn
CONTROL
LOGIC
DIN
PD
8
PDn
2
VDD
GND
7
2
VDD
GND
7
2
VDD
GND
7
INH
3
CLK
4
SP
EN
6
DOUT
SN
5
4
DO1
3
INH
EN
6
DO2
3
INH
EN
6
DOn
CLK
SP
DOUT
SN
5
4
CLK
SP
DOUT
SN
5
iC−NE
iC−NE
iC−NE
SN
SP
GND
Figure 8: Schematic of a chain configuration
When discussing the function of iC-NE, it is assumed
that all flip-flops in IC1...ICn have been reset, for ex-
ample after the operating voltage has been switched
on.
The signal DIN1 = hi activates the IC1 bandpass am-
plifier and the bias of the differential output stage. Out-
puts SP and SN remain tri-state until the rising CLK
edge shifts in the input hi signal.
ICHAUS [ IC-HAUS GMBH ]
