555

Could you clarify what you want about "555"? It could mean a few things. Here are the main possibilities:

• The number 555 (math)

  • Factorization: 555 = 3 × 5 × 37
  • Divisible by: 3, 5, 15, 37, 111, 185, 555
  • Roman numeral: DLV
  • Binary: 1000101011₂
  • Hex: 0x22B

• The 555 timer IC (electronics)

  • Common configurations: astable (oscillator) and monostable (one-shot)
  • Astable formulas (approx): f ≈ 1.44 / [(R1 + 2R2) C]
    • Tone widths: t_high ≈ 0.693 (R1 + R2) C, t_low ≈ 0.693 R2 C
  • Monostable (one-shot) pulse width: t ≈ 1.1 R C
  • Key pins: trigger, threshold, discharge, control, output; trigger levels at 1/3 Vcc and 2/3 Vcc
  • Useful applications: timers, PWM, pulse generation, delays

• The Roman numeral angle: 555 = DLV

Which of these would you like me to dive into? I can give a quick explanation, worked examples, or generate practice problems.