—9—

CXA3176N

6) Quick Charge

In order to hasten the rise time of Pin 7 from when power is turned on, the CXA3176N features a quick

charge circuit. The capacitance value connected to Pin 7 should be chosen such that the voltage does not

vary much due to discharge during battery saving.

Connect a signal for controlling the quick charge circuit to Pin 18. Setting this pin high enables the quick

charge mode, and setting this pin low enables the steady-state reception mode. Quick charge is used

when the power supply is turned on. The battery saving must be set high at the time.

Connect Pin 18 to GND when quick charge is not being used.

7) Detector

The detector is of quadrature type. To perform phase shift, connect a ceramic discriminator to Pin 8.

The phase shifting capacitor for the quadrature detector is incorporated. The FM signal demodulated with

the detector will be output to AMP_OUT (Pin 14) through the internal LPF.

The CDBC450CX50 (MURATA MFG. CO., LTD.) ceramic discriminator is recommended for the

CXA3176N.

Fig. 3

Fig. 4

5.6k

7

8

9

Ceramic

discriminator

CDBC450CX50

H

L

H

L

active

battery

saving

5ms

1ms

1ms

Power supply

(Pin 4)

Quick charge

(Pin 18)

Battery saving

(Pin 17)

Timing