app
Adom Fields
Public Made by Adomby adom
Adom Fields: where the current and the heat go on your board.
main
John Lauer
adom-fields 0.7.15: oscillators count five harmonics and their own circuit is not a crosstalk victim, ESD arrays by par…
2c6b424
adom-fields 0.7.15
Tested on a second kind of board, a discrete AM/FM superhet receiver (adom/amfm-receiver-molecule): oscillators instead of a switching converter, filtered rails instead of regulators.
- Oscillators and crystals. A clock net with a crystal on it, or an LC oscillator no chip drives, swings nearly as a sine: only its first five harmonics count as strong tones (its 50th harmonic no longer makes a plane resonance finding). A logic clock keeps its harmonics.
- An oscillator's own circuit is not its victim. For a clock, nets within two discrete parts of it (its crystal's other pin, its transistor's base and emitter) are coupled by design and are not crosstalk findings; a chip's other pins (an MCU's NRST beside its crystal) still are.
- ESD arrays by part number. USBLC6, TPD…, PESD…, SP05… on a line and ground count as protection; unconnected connector pins are skipped.
- Filtered rails in the PDN check. A rail fed through a ferrite, a fuse, an OR-ing diode, a resistor or a transistor switch from another rail is followed up to its connector or regulator and modelled as one source branch (a ferrite as its DC resistance plus a lossy inductance at its rated impedance).
# adom-fields 0.7.15
Tested on a second kind of board, a discrete AM/FM superhet receiver (adom/amfm-receiver-molecule): oscillators instead of a switching converter, filtered rails instead of regulators.
- **Oscillators and crystals.** A clock net with a crystal on it, or an LC oscillator no chip drives, swings nearly as a sine: only its first five harmonics count as strong tones (its 50th harmonic no longer makes a plane resonance finding). A logic clock keeps its harmonics.
- **An oscillator's own circuit is not its victim.** For a clock, nets within two discrete parts of it (its crystal's other pin, its transistor's base and emitter) are coupled by design and are not crosstalk findings; a chip's other pins (an MCU's NRST beside its crystal) still are.
- **ESD arrays by part number.** USBLC6, TPD…, PESD…, SP05… on a line and ground count as protection; unconnected connector pins are skipped.
- **Filtered rails in the PDN check.** A rail fed through a ferrite, a fuse, an OR-ing diode, a resistor or a transistor switch from another rail is followed up to its connector or regulator and modelled as one source branch (a ferrite as its DC resistance plus a lossy inductance at its rated impedance).