X9250_06 Datasheet, PDF (18/20 Pages) Intersil Corporation – Quad Digitally Controlled Potentiometers

Application Circuits (continued)
Attenuator
X9250
V_S
R₁
R₂
–
V_S
+
V_O
R₃
R_{4 R1 = R2 = R3 = R4 = 10kΩ}
Filter
C
+
–
R
R₁
V_O
R₂
V_O = G V_S
-1/2 ≤ G ≤ +1/2
G_O = 1 + R₂/R₁
fc = 1/(2πRC)
Inverting Amplifier
R₁ R₂
V_S
–
+
V_O
V_O = G V_S
G = - R₂/R₁
Equivalent L-R Circuit
C₁
V_S
Z_IN
R₂
+
–
R₁
R₃
Z_IN = R₂ + s R₂ (R₁ + R₃) C₁ = R₂ + s Leq
(R₁ + R₃) >> R₂
–
R₂
R₁
+
} ^RA
} ^RB
frequency ∝ R₁, R₂, C
amplitude ∝ R_A, R_B
C
–
+
18
FN8165.3
August 29, 2006