LA1265

No.1820-5/15

–

Parameter Frequency

–

Admittance

Unit

IF

γi1

10.7MHz

330

Ω

20

pF

FM

–

Parameter Frequency

–

RF

γi19

1MHz

Admittance

Unit

k

Ω

pF

AGC-off (V16=1.4V)

AGC-on (V16=2.5V)

15

16

4

4

MIX

γo17

500kHz

k

Ω

pF

–

–

3

3

IF

γi15

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 22 and 21 is large, a parasitic oscillation of approximately 100MHz may

occur in the buffer output (pin 22). In this case, connect a capacitance of approximately 30pF across pin 22 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.

If pin 8 is used for the stop signal (SD) only, without using LED, it is recommended to fix

9. To prevent whistle from worsening, make the pattern of AM output pin 12 as short as

possible.

Input/Output Admittance

T1 4147-1457-177 (Sumida)

T2 HW-40174 (Mitsumi)

T3a HW-40130, T3b HW-40131 (Mitsumi)

Unit (resistance :

Ω, capacitance : F)