SM5309A

SEIKO NPC CORPORATION —11

FUNCTIONAL DESCRIPTION

1) Cutoff frequency

2) Input multiplexer selection

3) fc mode switching (1/2 cutoff frequency switching)

4) Filter mode/filter bypass mode switching

5) Input type switching (sync-tip clamp, bias, direct)

6) Power-down function

support a read function (IC is write only).

Basic cycle

The basic access cycle comprises the following elements.

1) Start condition

2) 1st byte: Slave address

3) 2nd byte: Subaddress

4) 3rd byte: Control data

5) Stop condition

If the input data does not match the slave address or the subaddress is incorrect, the corresponding ACK

(acknowledge) bit is not output LOW. However, the ACK bit is output after 3rd byte irrespective of the byte

data. Also note that the IC does not support a subaddress auto-increment function, hence each subaddress

access requires all the basic cycle steps 1 to 5.

SDA

SCL

Start condition

Stop condition

SCL

1

SDA

Start

Stop

1st byte:Slave address

2nd byte:Subaddress

3rd byte:Control data

D7

D6

D1

D0

Low

ACK

D7

D6

D1

D0

ACK

D7

D6

D1

D0

ACK

27

8

9

1

2

7

8

9

1

2

7

8

9