Debouncer

τ ≈ C × (R1 + R2)

I ≈ V / R1 (resistive)

V = 3.3 V, R1 = 6.2 kΩ, R2 = 15 kΩ, C = 0.01 μF

τ ≈ 0.01 μF × (6.2 kΩ + 15 kΩ) = 0.2 msec

I ≈ 3.3 V / 6.2 kΩ = 0.5 mA

Forward current

I_F = (V − V_F − V_OL) / R

Red

V = 5 V, R = 560 Ω

I_F = (5 V − [2.0 – 2.4 V] − [0 – 0.4 V]) / 560 Ω ≈ 4 – 5 mA

Green

V = 5 V, R = 220 Ω

I_F = (5 V − [3.3 – 3.7 V] − [0 – 0.4 V]) / 220 Ω ≈ 4 – 8 mA

Blue

V = 5 V, R = 220 Ω

I_F = (5 V − [3.3 – 3.7 V] − [0 – 0.4 V]) / 220 Ω ≈ 4 – 8 mA

Debouncer

R1, R2 ≪ R3 :

τ ≈ C × R3

V1 ≈ V × (R2 / (R1 + R2))

I ≈ V / (R1 + R2) (resistive)

V = 5 V, R1 = 1 kΩ, R2 = 1.5 kΩ, R3 = 10 kΩ, C = 1 μF

τ ≈ 1 μF × 10 kΩ = 10 msec

V1 ≈ 5 V × (1.5 kΩ / (1 kΩ + 1.5 kΩ)) = 3 V

I ≈ 5 V / (1 kΩ + 1.5 kΩ) = 2 mA