Pin Functions

Operation

1. Data Input Procedure

The LC78211, LC78212 and LC78213 are controlled by inputting specified data to the CL, DI and CE pins. The

input data consists of 12 bits, of which four bits are address and eight bits are data.

Bits correspond to the L1 to L8 and R1 to R8 analog switches, and a value of one turns the corresponding switch on,

and a value of zero turns it off.

0.........Off

1.........On

The address is used when the chip is connected to a shared bus. The data (address) that must be transmitted depends

on the S pin and the particular product as shown in the table below.

Note: The bit for switch eight in the LC78213 is a “don’t care” bit, that is it can be either 0 or 1 without affecting

chip function. This is because the LC78213 has two sets of seven (not eight) circuits.

No. 4817-5/6

LC78211, 78212, 78213

Pin

I/O

Internal equivalent circuit

Pin function

L1 to L8, R1 to R8,

LCOM1 to LCOM4,

RCOM1 to RCOM4

CL, DI, CE

S

RES

I

I

I

See the block diagram.

Power supply

Analog switch input and output

Serial data input (Schmitt buffer)

CL ..............Clock input

DI ...............Data input

CE .............Chip enable

Selection of one of two chips

The address is set to the values shown in the table below according to

the level input to the S pin.

Reset input

The states of the analog switches are undefined when power is first

applied. Setting this pin low will force all switches the off state.

Product

S pin

Address

level

LC78211

L

0

1

0

1

H

1

1

0

1

LC78212

L

0

0

1

1

H

1

0

1

1

LC78213

L

0

1

1

1

H

1

1

1

1

Product

S pin

Address

level

LC78211

L

0

1

0

1

H

1

1

0

1

LC78212

L

0

0

1

1

H

1

0

1

1

LC78213

L

0

1

1

1

H

1

1

1

1