2016-12-21 01:51:11 +08:00
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# RFTool Rev 1.0 Hardware Errata and Notes
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- The Schottky diode for the +3.3V buck converter is missing. Connect a
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Schottky such as the MBR0520 between ground and the SW pin of U4.
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- The connector part in the BOM used for P5 (JTAG) does not have enough clearance
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to fit the connector on the JTAG ribbon cable, at least for the cable included with my Waveshare
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dongle. Ideally another connector should be used.
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- Trace widths will need to be adjusted to meet impedance requirements depending on your stackup.
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`rftool_impedances.png` shows impedance control requirements. Green is 50Ω single ended; blue is 50Ω differential
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and yellow is 75Ω differential. The USB 3 pairs were not included in this diagram but should be 100Ω differential.
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2016-12-24 21:37:12 +08:00
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- It is not possible to use both receive channels simultaneously as channel 1 uses ports 1A and 1B; whereas 2 uses port 2C
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and the AD9361 does not support using different port letters at the same time. Ideally the design should be changed
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so the second LNA connects to 2B; or the first LNA connects to 1C.
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- The ENABLE pin of the Skyworks LNAs (pin 6 of U2 and U21) is active low but was mistakenly connected to +3V rather than
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ground. Cutting the trace going to this pin enables the LNAs to work properly.
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