IL300-D Infineon Technologies, IL300-D Datasheet - Page 11

• Manufacturer Part Number: IL300-D
• Manufacturer: Infineon Technologies

Specifications of IL300-D

• Lead Free Status / Rohs Status: Supplier Unconfirmed

The last step in the design is selecting the LED cur-
rent limiting resistor (R4). The output of the opera-
tional amplifier is targeted to be 50 % of the V
2.5 V. With an LED quiescent current of 12 mA the
typical LED (V
tional output voltage, R4 can be calculated.
The circuit was constructed with an LM201 differential
operational amplifier using the resistors selected. The
amplifier was compensated with a 100 pF capacitor
connected between pins 1 and 8.
The DC transfer characteristics are shown in Figure
19. The amplifier was designed to have a gain of 0.6
and was measured to be 0.6036. Greater accuracy
can be achieved by adding a balancing circuit, and
potentiometer in the input divider, or at R5. The circuit
shows exceptionally good gain linearity with an RMS
error of only 0.0133 % over the input voltage range of
4.0 V - 6.0 V in a servo mode; see Figure 20.
Document Number 83622
Rev. 1.5, 24-Mar-05
VISHAY
iil300_19
R4 =
3.75
3.50
3.25
3.00
2.75
2.50
2.25
V
4.0
opamp
I
Fq
Vout = 14.4 mV + 0.6036 x Vin
LM 201 Ta = 25°C
- V F
F
4.5
) is 1.3 V. Given this and the opera-
Figure 19. Transfer Gain
=
2.5 V - 1.3 V
12 mA
5.0
= 100
5.5
17096
6.0
CC
, or
The AC characteristics are also quite impressive
offering a - 3.0 dB bandwidth of 100 kHz, with a -45 °
phase shift at 80 kHz as shown in Figure 21.
The same procedure can be used to design isolation
amplifiers that accept bipolar signals referenced to
ground. These amplifiers circuit configurations are
shown in Figure 22. In order for the amplifier to
respond to a signal that swings above and below
ground, the LED must be pre biased from a separate
source by using a voltage reference source (V
these designs, R3 can be determined by the following
equation.
iil300_20
iil300_21
R3 =
-0.005
-0.010
-0.015
0.025
0.020
0.015
0.010
0.005
0.000
-2
-4
-6
-8
2
0
Figure 21. Amplitude and Phase Power Supply Control
10 3
4.0
V
I
P1
ref1
Figure 20. Linearity Error vs. Input Voltage
LM201
=
K1I
V
4.5
ref1
10 4
F - Frequency - Hz
Vin - Input Voltage - V
Fq
Vishay Semiconductors
5.0
10 5
17098
dB
PHASE
5.5
10 6
www.vishay.com
45
0
-45
-90
-135
-180
IL300
6.0
ref1
). In
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