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1. Introduction
The Si871x evaluation board allows designers to evaluate Silicon Lab's family of CMOS based LED Emulator Input
isolators. The Si871x isolators are pin-compatible, single-channel, drop-in replacements for popular optocouplers
with data rates up to 15 Mbps. These devices isolate high-speed signals and offer performance, reliability, and
flexibility advantages not available with optocoupler solutions. The Si871x series is based on Silicon Labs'
proprietary CMOS isolation technology for low-power and high-speed operation and are resistant to the wear-out
effects found in optocouplers that degrade performance with increasing temperature, forward current, and device
age. As a result, the Si871x series offer longer service life and dramatically higher reliability compared to
optocouplers. Ordering options for the family include a push-pull output stage with or without an output enable pin
to select a default output state (Hi-Z, logic-low, or logic-high). The evaluation kit consists of three separately
orderable boards with each board featuring either the DIP8, SOIC8, or SDIP6 package. For more information on
configuring the isolator itself, see the Si871x product data sheet and as well as application note “AN681: Using the
Si87xx Family of Digital Isolators”.
1.1. Kit Contents
The Si871x Evaluation Kit contains the following items:
Si871x
based evaluation board as shown in Figures 1 through 3.
Si871x LED Emulator Input isolator (installed on the evaluation board)
Si8718
(DIP8, SOIC8)
Si8719 (SDIP6)
Figure 1. Si871x DIP8 Evaluation Board Overview
Figure 2. Si871x SOIC8 Evaluation Board Overview
Rev. 0.1 6/14
Copyright © 2014 by Silicon Laboratories
Si871x-EVB
Si871x-EVB
Figure 3. Si871x SDIP6 Evaluation Board Overview
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Rev. 0.1
Si871x-EVB
2. Required Equipment
The following equipment is required to demonstrate the evaluation board:
digital multimeter
2 multimeter test leads (red and black)
1 oscilloscope (Tektronix TDS 2024B or equivalent)
1 BNC splitter
3 coaxial cables
1 dc power supply (HP6024A, 30 V dc, 0–100 mA or equivalent)
2 BNC to clip converters (red and black)
2 Banana to clip wires (red and black)
1 Clip to Clip wire (any color)
1 function generator (Agilent 33220A, 20 MHz or equivalent)
Si871x Evaluation Board (board under test)
Si871x LED Emulator Input Evaluation Board User's Guide (this document)
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Rev. 0.1
3
Si871x-EVB
3. Hardware Overview and Demo
Figure 4 illustrates the connection diagram to demonstrate the Si871x-DIP8 EVB. The other footprint boards
demonstrate in a similar fashion. This demo transmits a 500 kHz (5 V peak, 50 percent duty cycle) square wave
through the isolator to its output (Vo). In this example, VDD is powered by a 5 V supply. Figure 5 shows a scope
shot of CH1 (input) and CH2 (output). Note that if a user wants to evaluate an LED Emulator Input isolator other
than the ones prepopulated, this can be accomplished by removing the installed device and replacing it with the
desired footprint-compatible isolator device.
Input to
Scope CH1
Output to
Scope CH2
Signal Input
(500 kHz, 5 Vpk)
Square Wave
+
_
+
_
Power Supply
(5 V)
Figure 4. Summary Diagram and Test Setup
Figure 5. Oscilloscope Display of Input and Output
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Rev. 0.1
Si871x-EVB
3.1. Board Jumper Settings
To run the demo, follow the instructions below. Review Figure 4 and Figures 9 through 11 if necessary.
1. If demonstrating the SOIC8 or DIP8 EVB featuring the Si8718, ensure that J2 is installed as shown in
Figure 1 or 2.
2. If demonstrating the SDIP6 EVB featuring the Si8719, ensure that J2 is installed as shown in Figure 3.
3.2. DC Supply Configuration
1. Turn OFF the dc power supply and ensure that the output voltage is set to its lowest output voltage.
2. Connect the banana ends of the black and red banana to clip terminated wires to the outputs of the dc
supply.
3. Then, connect the clip end of the red and black banana to clip wires to P2. The red wire goes to Pin1. The
black wire goes to Pin4.
4. Turn ON the dc power supply.
5. Adjust the dc power supply to provide 5 V on its output.
6. Ensure that the current draw is less than 25 mA. If it is larger, this indicates that either the board or Si871x
has been damaged or the supply is connected backwards.
3.3. Wave Form Generator
1. Turn ON the arbitrary waveform generator with the output disengaged.
2. Adjust its output to provide a 500 kHz, 0 to 5 V peak square wave (50 percent duty cycle) to its output.
3. Split the output of the generator with a BNC splitter.
4. From the BNC splitter, connect a coaxial cable to CH1 of the scope. This will be the input.
5. Connect a second coaxial cable to the BNC splitter, and connect a BNC-to-clip converter to the end of the
coaxial cable.
6. From here, connect the clip end of the BNC-to-clip converter to P1, Pin1 (red wire here) and Pin3 (black
wire here). The positive terminal is Pin1 on P1.
7. Connect one end of a third coaxial cable to a BNC-to-clip converter (note that a scope probe can be used
here instead).
8. From here, connect the clip end of the BNC-to-clip converter to P2, Pin3 (red wire here) and Pin4 (black
wire here). Vo is on P2 Pin3.
9. Connect the other end of the coaxial cable to CH2 of the oscilloscope. This will be the output.
10. Engage the output of the waveform generator.
3.4. Oscilloscope Setup
1. Turn ON the oscilloscope.
2. Set the scope to Trigger on CH1 and adjust the trigger level to 1 V minimum.
3. Set CH1and CH2 to 2 V per division.
4. Adjust the seconds/division setting to 400 ns/division.
5. Adjust the level indicator for all channels to properly view each channel as shown in Figure 5.
A 500 kHz square wave should display on Channel 1 of the scope for the input and a 5 V delayed and inverted
version of this square wave should display the output on Channel 2, as shown in Figure 5. This concludes the
basic demo. For more advanced demos, see the following sections.
Rev. 0.1
5
