Recommended Interface Circuit for SP0103N Integrated Amplifier
V+
Term 4 = V
dd
Vout
Term 1 = Output
R1 = 22kΩ
R2 = 2.4kΩ
Term 3 = Ground
Term 2 = Gain Control
R3 (set by customer)
C1 (set by customer)
Desired Gain
Unity Gain (0dB)
20dB Gain
Adjustable Gain
Pin 2 Termination Method
Tie Terminal 2 directly to Output (Terminal 1).
Tie Terminal 2 through C1 (0.47uF) to Ground.
Add R3 and C1. Use formulas provided to calculate
settings, or contact Knowles for support.
Setting Gain Formulas:
Gain of non-inverting Op-Amp is determined as:
G=1+ {R1 / (R2 + R3)}
Gain(dB) = 20 * log(G)
High-pass-filter Corner Frequency:
C.F. = 1 / {2*pi*(R2 + R3) * C1}
Knowles Acoustics
www.knowlesacoustics.com
Rev H
SP0103NC3
KNOWLES [ KNOWLES ELECTRONICS ]
