KK33197A
Recommended External Component Values
Below are the recommended component values to ensure the device will operate properly, and that all specified
parameters will stay within their tolerances. R1 should be greater than 100Ω; recommended value of 220Ω. R1 can be
up to 500Ω, but in this case the tb2v parameter could be out of it’s specified value (see Electrical Characteristics and
Note 1). Also, the minimum operating voltage range should be greater than 8.0 V. The following values should be
adhered to:
10 k≤R2
≤
68 kΩ
1.5 kΩ
≤
R3
≤
47 kΩ
R4
≥
4.7 kΩ
R5
≥
4.7 kΩ
C1≥
47 uF
47 nF
≤
C2
≤
470 Nf
Application Information
The following is an example of timing calculations using the following external components values:
R2 = 22 kΩ, R3 = 2.2 kΩ, C2 = 100 nF (Referring to Block Diagram and Typical Application).
Oscillator Time Base Calculation:
t
b1
duration = t
b1
× 4 × R2 × C2 = 1 × 4 × 27e
3
× 100e–9 = 10.8 ms
t
b2
duration_g (INT to Gnd) = t
b2g
× R3 × C2 = 15.5 × 2.2e
3
× 100e–9 = 3.41 ms
t
b2
duration_v (INT to Vbb) = t
b2v
× R3 × C2 = 12.1 × 2.2e
3
× 100e–9 = 2.66 ms
Intermittent timing calculation:
T3 = 16 × 4 × t
b1
duration = 16 × 4 × 10.8 ms = 691 ms
T4 = 144 × 4 × t
b2
duration_g = 144 × 4 × 3.41 ms = 1.96 s
(INT connected to Gnd)
T4 = 144 × 4 × t
b2
duration_v = 144 × 4 × 2.66 ms = 1.53 s
(INT connected to Vbb)
Wash wipe timing calculation:
T2 = 96 × 4 × t
b1
= 96 × 4 × 10.8 ms = 4.15 s
T1 Debounce Time Calculation (see T1 Debounce Timing)
When oscillator is oscillating at tb1:
T1 minimum = 4 × t
b1
= 4 × 10.8 ms = 43.2 ms
T1 maximum = 2 × 4 × t
b1
= 2 × 4 × 10.8 ms = 86.4 ms
When oscillator is oscillating at tb2:
T1 minimum (INT connected to Gnd, t
b2g
) = 4 × t
b2
= 4 ×3.41 ms = 13.6 ms
T1 maximum (INT connected to Gnd, t
b2g
) = 2 × 4 × t
b2
= 2 × 4 × 3.41 ms = 27.3 ms
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