Audio ICs
Pin No.
Function
MPX input
14
Input the FM detector output .
MPX input
15
Input the AM detector output after
low cut.
AM/FM detector output
16
Connect to the following stage MPX and
FM low pass filter.
AM AGC
17
Connect to a capacitor.
AM IF input
18
Connect to an AM ceramic filter.
Internal circuit
VCC 2
Vreg 23
14
15
GND 4
VCC 2
GND 4
VCC 2
16
5kΩ
17
GND 4
VCC 2
18
20kΩ
GND 4
19
AM mixer output
VCC 2
19
Vreg 23
Connect to primary side of AM IFT.
20
AM antenna
20
Connect to AM antenna.
GND 4
BA1451F
Quiescent pin voltage (V)
FM
AM
2.1
2.1
2.1
2.1
2.1
2.1
0
0
5.0
5.0
5.0
5.0
2.1
2.1