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•
T1 = FDN335N (for example)
•
R2 = 0Ω
•
R3 = 1MΩ
Note:
A low filter is recommended at low frequencies.
Low Filter Calculations
To compute for the cut‐off frequency, use the formula Fc = 1/(2*Π*Req*C1) where:
•
Fc = cut‐off frequency
•
Req = the total resistors in line
•
C1 = the capacitive charge on T1 and the ground
Bear in mind that:
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Fc must be higher than FBUZZ‐OUT
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Fc must be at least 64 * FBUZZ‐OUT
Note:
The frequency modulation of the BUZZER signal is 64*FBUZZ-OUT.
Recommended Characteristics
•
Electro‐magnetic type
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Impedance: 7 to 30Ω
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Sensitivity: 90 dB SPL min @ 10 cm
•
Current: 60 to 90mA
The BUZZER output can also be used to drive an LED as shown in the figure below.
WA_DEV_W228_PTS_002
Rev 001
Product Technical Specification &
Customer Design Guidelines
Page 70 of 108
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