(5) Sample RF alignment coil selectivity characteristics (Mitsumi)

New coil designs should have the same selectivity characteristics as shown below.

5.

Problems Concerning Wideband AGC

Because the LA1136N and the LA1137N offer many sophisticated functions, a number of their pins are dual-purpose pins. An

example is pin 3 (on both the LA1136N and the LA1137N), which serves both as the wideband AGC input pin and the antenna

dumping pin diode drive pin. As a result, particular attention must be given to the wiring pattern layout, since feedthrough of other

signals as shown in the figure below can cause AGC to operate without input, resulting in reduced sensitivity.

RF characteristics at 600 kHz

RF characteristics at 1 MHz

RF characteristics at 1.4 MHz

Avoid direct

feedthrough from the

RF amplifier to the

pin 3 line.

LA1136N/1137N Antenna, RF circuit

Unit (resistance:

Ω, capacitance: F)

LA1136N, 1136NM, 1137N, 1137NM

No. 3507-15/28