AND8054 Datasheet, PDF (24/28 Pages) ON Semiconductor – Designing RC Oscillator Circuits with Low Voltage Operational Amplifiers and Comparators for Precision Sensor Applications

AND8054/D
R11
R1
V11
C1
A1
R2
V₁
C2
A2
R3
V₂
C4
R4
A3
V₃
Figure 29. Schematic of the Absolute Oscillator with Rll that is Used to Obtain T(s),
using Mason’s Reduction Theorem
Absolute Oscillator (without C₄)
Assume R₁ >> R₁₁, then R₁ + R₁₁ ` R₁
ǒ Ǔǒ Ǔǒ Ǔ P1 + LG1 + A1
A2
A3 +
–
1
sR1C1
–
1
sR2C2
–
R4
R3
ǒ Ǔǒ Ǔǒ Ǔ Ds + 1 * LG1 + 1 *
–
1
sR1C1
–
1
sR2C2
–
R4
R3
+
1
)
R4
s2R1R2R3C1C2
+
s2R1R2R3C1C2 ) R4
s2R1R2R3C1C2
ǒ ^R4 Ǔ
ǒ Ǔ ^T(s)
+
V3
V11
+
P1
Ds
+
s2R1R2R3C1C2
s2R1R2R3C1C2)R4
+
* R4
s2R1R2R3C1C2
)
R4
s2R1R2R3C1C2
Absolute Oscillator (with C₄)
Assume R₁ >> R₁₁, then R₁ + R₁₁ ` R₁
P1 + LG + A1 A2 A3
ǒ Ǔǒ Ǔƪǒ Ǔǒ Ǔƫ P1 + LG +
–
1
sR1C1
–
1
sR2C2
–
R4
R3
1
sR4C4 ) 1
+
–
* R4
s3R1R2R3R4C1C2C4 )
s2R1R2R3C1C2
Ds
+
1
*
LG
+
1
)
R4
s3R1R2R3R4C1C2C4
)
s2R1R2R3C1C2
+
s3R1R2R3R4C1C2C4 )
s3R1R2R3R4C1C2C4
s2R1R2R3C1C2 ) R4
) s2R1R2R3C1C2
ǒ
*R4
Ǔ
ǒ Ǔ ^T(s)
+
P1
Ds
+
s3R1R2R3R4C1C2C4)s2R1R2R3C1C2
s3R1R2R3R4C1C2C4)s2R1R2R3C1C2)R4
+
* R4
s3R1R2R3R4C1C2C4 ⁾ s2R1R2R3C1C2
)
R4
s3R1R2R3R4C1C2C4⁾s2R1R2R3C1C2
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