42 lines
1.4 KiB
Markdown
42 lines
1.4 KiB
Markdown
Hardware errata
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===============
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Rev 1
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* R307 needs more clearance from D400
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* Pins 1 and 12 of U502 need pull-downs
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* Pin 1 of U501 needs pull-up
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* D203 reversed polarity
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* R236 and R234 are swapped
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* Q301 needs to be NPN, change to BC817
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* increase R307 -> 3.3Kohm and increase R500 -> 33Kohm
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* C201: oscillates at 0 and 1nF, stable at 100nF
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* add clamp diodes to GND on op-amp outputs to ADC when op-amp has negative supply
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* R214 -> 7.5k
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* LM339PT is in TSSOP package. Change for SOIC P/N
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* GDT200 minimum firing voltage is too low
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* the relay model should be changed to 9001-05-00. 9001-05-02 is an undocumented normally closed variant.
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* D504 should follow the schematics in its datasheet
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* R502 should be connected to VCC
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* R502 -> 240 ohm
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* C500 -> 1nF
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* R234 -> 7.5k
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* Q104 -> DMN3404
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* R114 -> 470 ohm
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* R115 -> 4.7k
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* R227 -> 470 ohm
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* R228 -> 4.7k
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* review values of R226 and R113
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* C100 -> 47pF NP0 AVX, R107 -> 100K, C101 -> 0.1uF
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* use crystal type recommended by the MCU datasheet
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* 22k FBI current resistor -> 10k?
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* add connector for OLED display?
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* enlarge holes to fit M3 screws comfortably
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* add 15M (TBC) resistor between A and FIL-
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* power U200 from a small negative voltage instead of GND
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* review choice of filament flyback output diode
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* invert LED position so that the Ethernet LED is closest to the connector
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* invert polarity of LEDs (Ethernet LED polarity cannot be programmed)
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* Meanwell DC/DC is coupling noise into pA input
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