cxd2548r Sony Electronics, cxd2548r Datasheet - Page 73

• Manufacturer Part Number: cxd2548r
• Description: Cd Digital Signal Processor With Built-in Digital Servo And Dac
• Manufacturer: Sony Electronics

3-11. LPF Block
The CXD2548R 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 (V
The LPF block application circuit is shown below.
In this circuit, the cut-off frequency is fc
The capacitance of the external capacitors when fc = 30kHz and 50kHz are noted below as a reference.
LPF Block Application Circuit
• When fc
• When fc
C1 = 200pF, C2 = 910pF
C1 = 120pF, C2 = 560pF
30kHz:
50kHz:
Vc
C
AOUT1 (2)
LOUT1 (2)
) is (AV
AIN1 (2)
DD
– AV
Fig. 3-12. LPF External Circuit
SS
40kHz.
)/2.
150p
C1
12k
12k
– 73 –
12k
680p
C2
Analog out
CXD2548R