Pin Functions

Pin

Function

LC

Loop Current Input. Signal from phone line to be monitored for dial pulse signaling and hook status. Active low,

internally pulled high.

OH

Off-hook Output. Hook status of phone line. Active (off-hook) high.

10/20

Pulse Speed Input. Low for 10 pulse per second, high for 20 pulse per second. Internally pulled low.

D3-D0

Data Outputs. Binary decoded rotary dialed digit. Active during valid digit time (strobe high), low at any other time.

Digit Dialed D3

D2

D1

D0

10

0

0

1

20

0

1

0

30

0

1

1

40

1

0

0

50

1

0

1

60

1

1

0

70

1

1

1

81

0

0

0

91

0

0

1

01

0

1

0

OE

Output Enable Input. Active high, a log low tri-states D3 through D0 outputs. Internally pulled high.

XIN

Crystal Oscillator Input

XOUT

Crystal Oscillator Output.

Clear

Strobe Control Input. Momentary high during digit valid time resets STROBE latch output low until next valid

digit is received. Internally pulled low.

Strobe

Digit Valid Output. Indicates valid digit data present on D3 through D0. Active high.

M-959

www.clare.com

3

Rev. 3

Timing Diagram