CXD3018Q/R
§4-12. LPF Block
The CXD3018Q/R contains an initial-stage secondary active LPF with numerous resistors and capacitors and
an operational amplifier with reference voltage.
The resistors and capacitors are attached externally, allowing the cut-off frequency fc to be determined flexibly.
The reference voltage (VC) is (AVDD – AVSS) × 0.45.
The LPF block application circuit is shown below.
In this circuit, the cut-off frequency is fc ≈ 40kHz.
LPF Block Application Circuit
27k
27k
AOUT1 (2)
AIN1 (2)
C2
330pF
Vc
C1
68pF
27k
100
Analog out
LOUT1 (2)
Fig. 4-14. LPF External Circuit
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