CXA2500M/N
2. PB Mode:
To reduce the PB amplifier DC output offset, it is recommended that 39kΩ resistor be connected as shown
in the Application Circuit. However, too low this resistor value may affect the low frequency portion of the
PB frequency response. The inter-relationship of the RC values in the playback equalization network is as
shown below:
55
50
45
40
35
30
25
GV (dB)
CXA2500
+
PB
–
IN
TAPE PB: GV, THD vs f
VO = –15dBm
VCC = 2V
R1
NORMAL
METAL
330k
G1
G2
R3
22k
R2
15k
C1
0.01µ
R5
330
REF
R4
39k
C2
33µ
f1 f2
10
100
1k
10k
100k
f [Hz]
During Normal PB mode,
Gain G1 = 20 log (R2 + R5)/R5
3dB cut-off frequency, f1 = 1/(2 × 3.1416 × C1 × R2)
During Metal PB mode,
Gain G2 = 20 log (R2//R3 + R5)/R5
3dB cut-off frequency, f2 = 1/(2 × 3.1416 × C1 × R2//R3)
3. Use of RC at Tape/Tuner and PB/REC pins:
The purpose of the external RC components at the switch inputs is to create an internal mute pulse so as to
mute the REC OUT momentally during the switching operation. By doing so, the switching click noise that
may appear at REC OUT can be reduced. The selection of the RC values affects the duration of the mute
pulse. It is recommended to use resistor of 2.2kΩ and below at Tape/Tuner pin, i.e Pin 12. These RC
components may be removed if such internal pop noise countermeasure is not required.
– 10 –
SONY [ SONY CORPORATION ]
