LA1267

No.2012-5/14

–

Parameter Frequency

–

Admittance

Unit

IF

γi1

10.7MHz

330

Ω

20

pF

FM

–

Parameter Frequency

–

RF

γi21

1MHz

Admittance

Unit

k

Ω

pF

AGC-off (V16=1.4V)

AGC-on (V16=2.5V)

15

16

4

4

MIX

γo19

500kHz

k

Ω

pF

–

–

3

3

IF

γi17

500kHz

k

Ω

pF

2

2

10

8

AM

6. If the coupling coefficient of the local OSC coil is small and an antiresonance point of approximately 100MHz is

present or the stray capacitance across pins 24 and 23 is large, a parasitic oscillation of approximately 100MHz may

occur in the buffer output (pin 24). In this case, connect a capacitance of approximately 30pF across pin 24 and GND.

7. AM OSC coil

Generally speaking, the following should be noted. Avoid winding with loose coupling between primary side and

secondary side (especially SW1, SW2). To put it concretely, the pot core type is better than the screw core type which

is loose in coupling. This prevents the local OSC frequency from turning third resonance frequency related to the

coupling coefficient.

and GND to be 51k

Ω to 100kΩ.

9. To prevent whistle from worsening, make the pattern of AM output pin 14 as short as possible.

Input/Output Admittance

T1 : 4147-1457-177 (Sumida)

T2 : HW-40174 (Mitsumi)

T3 : HW-40130, 40131 (Mitsumi)

Unit (resistance :

Ω, capacitance : F)