3

Pin Number Function

No connection

Decoder Output : The recovered analogue signal is output at this pin, it is the buffered

output of a bandpass filter and requires external components. During "Powersave" this

output is o/c.

No connection

Powersave : A logical '0' at this pin puts most parts of the codec into a quiescent non-

operational state. When at a logical '1' the codec operates normally. Internal 1M

Ω Pullup.

Decoder Force Idle : A logical '0' at this pin gates a 0101...pattern internally to the

decoder so that the decoder output goes to V

decoder operates as normal. Internal 1M

Ω Pullup.

Decoder Input : The received digital signal input. Internal 1M

Ω Pullup.

Decoder Data Clock : A Logic I/O port. External decode clock input or internal data clock

output, dependant upon clock mode 1, 2 inputs, see Clock Mode pins.

Algorithm : A logical '1' at this pin sets this device for a 3-bit companding algorithm. A

logical '0' sets a 4-bit companding algorithm. Internal 1M

Ω Pullup.

Clock Mode 2 :

Clock Mode 1

Clock Mode 2

Facility

Clock Mode 1 :

0

0

External clocks

Internal 1M

Ω

0

1

Internal, 64kb/s = f

÷ 16

Pullups.

1

0

Internal, 32kb/s = f

÷ 32

1

1

Internal, 16kb/s = f

÷ 64

Clock rates refer to f = 1.024 MHz Xtal/clock input. During internal operation the data clock

frequencies are available at the ports for external circuit synchronization.

Independent or common data rate inputs to Encode and Decode data clock ports may be

employed in the External Clocks mode. Optimum performance will be achieved when the

applied external clocks are synchronous with the master Xtal/clock, and a sub-multiple of

128kHz.

V

A single + 5 volt power supply is required.

FX629J

12

13

14

15

16

17

18

19

20

21

22