X9251_07 Datasheet, PDF (18/20 Pages) Intersil Corporation – Quad Digitally-Controlled (XDCP™) Potentiometer

Application Circuits (continued)
X9251
ATTENUATOR
V_S
R₁
R₂
–
V_S
+
V_O
R₃
R_{4 R1 = R2 = R3 = R4 = 10kΩ}
V_O = G V_S
-1/2 ≤ G ≤ +1/2
FILTER
C
+
–
R
R₁
V_O
R₂
G_O = 1 + R₂/R₁
fc = 1/(2πRC)
INVERTING AMPLIFIER
R₁ R₂
V_S
–
+
V_O
V_O = G V_S
G = - R₂/R₁
FUNCTION GENERATOR
–
R₂
+
} ^RA
} ^RB
frequency ∝ R₁, R₂, C
amplitude ∝ R_A, R_B
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
C
R₁
–
+
18
FN8166.5
April 13, 2007