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Communication ICs

PLL tone decoder IC

BA1604 / BA1604F

The BA1604 and BA1604F are tone decoder ICs that enable the frequency to be selected in precise detail, using a PLL

system. These ICs are configured of a PLL circuit, a detection circuit, a voltage comparator circuit and an output logic

drive circuit.

When the input signal is within the transmission range of the circuit, PLL is synchronized (locked) to the input signal.

At this point, the output voltage of the decoder drops, and the change turns on the transistors for the voltage comparator

the mobile oscillation frequency of the current control oscillator. This frequency is determined by selecting a CR con-

nected to Pins 5 and 6.

FApplications

Telephones

Data communication systems

Remote control systems

FFeatures

1) The detection bandwidth can be varied independent-

ly between 0 and 14%.

2) The output circuit can withstand a load current of up

to 100mA, and is directly coupled to the logic circuit.

3) The center frequency offers a high level of stability.

4) High out-of-band signal and noise rejection capabili-

ty.

5) Frequency can be changed over a range of 20 : 1 us-

ing an external resistor.

6) Compatible with EXAR XR-567 and Signetics

NE567.

FBlock diagram