Receiver Circuit Testing

1
Receiver Circuit Testing

• Test setup
• Eye diagrams
• BER measurement
• Eye - BER relationship

2
Circuit Test Setup

• Pattern Generator
• Attenuator
• Oscilloscope

3
Signal Monitoring

• Terminated 50 ??coax for gt 1 Mbps
• capacitance (NRZ data, 50 ohms)
• 1/2piRC gt data rate

4
RF Oscillation Prevention

• Grounded coax for all inputs
• Single ground point for bias

5
RF Circuit Test

• 50 ? transmission line to chip
• Stripline printed circuit boards
• or short lines
• 50 ? output drivers

6
BER Measurement

• PRBS source
• Attenuation
• Error measurement

7
PRBS source

• Pseudo random data is severe test of receiver
• Length of zero or one string is critical (ISI)
• Eye diagram is open for low ISI

8
Attenuation

• Sensitivity of receiver
• BER at fixed pin and data rate
• Noise floor due to dynamic range limits
• Need to vary pin

9
Error Measurement

• Correlate PRBS and output data
• BER number of errors / data bits sent
• BER 10-9 or 10-11 typical
• i.e., 1 error per Gbit of data 10-9