IL5851

PIN DESCRIPTION

NAME

PIN

DESCRIPTION

1

Positive supply pin.

The voltage on this pin is measured relative to Pin 6 and is supplied from a

150

µA current source. This voltage should be regulated to less than 6.0 volts

using on external form or regulation.

2

voltage

that

tracks

internal

provides a negative voltage reference

be approximately 0.6 volt higher than

the minimum operating voltage of

each particular IL5851N.

The typical application would be to

(Pin 1) should then be regulated to

150

µA (I

supply current, operation of the

IL5851N is guaranteed.

function is shown in Figure 1 with its

associated I-V characteristic

.

___ _____

Row1-Row4,

Col1-Col4

3,4,5,13,

14,15,16

Keyboard inputs.

The IL5851N incorporates an innovative keyboard scheme that allows either the

standard 2-of-7 keyboard with negative common or the inexpensive single

contact (form A) keyboard to be used.

A valid key entry is defined by either a single row being connected to a single

column or GND being simultaneously presented to both a single row and column.

When in the on-hook mode, the row and column inputs are held high and no

keyboard inputs are accepted.

When off-hook, the keyboard is completely static until the initial valid key input

is sensed. The oscillator is then enabled and the rows and columns are scanned

alternately (pulled high, then low) to verify the varied input. The input must

remain valid for 10msec of debounce time to be accepted.

Form A type keyboard

2 of 7 keyboard (negative common)

2 of 7 keyboard

Electronic input

GND

6

Negative supply

2