1

214

Communication ICs

BA1604 / BA1604F

FMeasurement circuit

FApplication example

FAttached components

(1)

6 and the ground. The constants at this point are deter-

mined as follows :

(kHz) (C :

µ F, R : kΩ)

A rectangular-wave voltage is output at Pin 5; the peak-

tance of up to 1k

however, is from 2k

Ω to 20kΩ.)

A 1V peak-to-peak exponential function triangular wave

6. Since loading this pin adversely affects both the duty

cycle and the temperature stability of the oscillator, it

must only be connected to a high-impedance load.

(2)

as a low pass filter for the PLL circuit, and the time

pedance for Pin 2, at 10 k

mines the detection bandwidth. The voltage at Pin 2 va-

(3)

is used as a low pass filter to suppress out-of-band sig-

is the internal impedance for Pin 1, at 4.7k

Ω).

To prevent false detection of spurious signals, it is recom-

er, this will increase the time required for voltage changes

at Pin 1 to reach the threshold of the phase detector, thus

slowing the response time.

(4)

(5)

FInput and output pins

(1)

Input : Pin 3

The input signal is applied through a coupling capacitor

to Pin 3. Internal circuits set this pin to a DC potential of

2V with respect to the ground. The input impedance is

approximately 20k

Ω.

(2)

Output : Pin 8

The output logic section has an internal power transistor

with its collector connected to Pin 8. The load is con-

when an in-band input signal is received, dropping the

potential at Pin 8 to less than 1V (0.6V Typ.). The output

can also drive a load connected to a separate supply volt-

age of up to 20V.