LA1837M

No.8271-6/9

Continued from preceding page.

Pin No.

Pin

Pin

voltage

Equivalent circuit

Pin function

24

AM detector

output

0V (FM)

0.5V (AM)

Output impedance ro = 3.3kΩ The AM frequency characteristics

can be adjusted with an RC circuit connected between pin 22 and

ground.

25

AM AGC

0V (FM)

0.5V (AM)

Internal load resistance R = 11k

Ω

26

AFC

Vreg

The FM SD bandwidth can be adjusted with an external resistor

connected between this pin and pin 28.

27

AM RF input

Vreg

This pin must be held at the same potential as pin 28

28

REG

Vreg

Vreg = 3.6V

29

OSC

Vreg

Connect the oscillator coil between this pin and pin 28.

30

Oscillator buffer

output, FM SD

sensitivity

adjustment

1.6V (FM)

1.3V (AM)

The FM SD sensitivity can be adjusted with an external resistor

connected between this pin and ground.

Output impedance ro = 20Ω