9397 750 14939

© Koninklijke Philips Electronics N.V. 2006. All rights reserved.

Product data sheet

Rev. 01 — 14 February 2006

7 of 30

Philips Semiconductors

PCA9506

[1]

be connected to supply ground for proper device operation. For enhanced thermal, electrical, and board

level performance, the exposed pad needs to be soldered to the board using a corresponding thermal pad

on the board and for proper heat conduction through the board, thermal vias need to be incorporated in the

printed-circuit board in the thermal pad region.

7.

Functional description

Refer to Figure 1 “Block diagram of PCA9506” and Figure 2 “Simplified schematic of

IO0_0 to IO4_7”.

7.1 Device address

Following a START condition, the bus master must send the address of the slave it is

accessing and the operation it wants to perform (read or write). The address of the

PCA9506 is shown in Figure 5. Slave address pins A2, A1, and A0 choose 1 of 8 slave

pull-up resistors are incorporated on A2, A1, and A0.

The last bit of the first byte defines the operation to be performed. When set to logic 1 a

read is selected, while a logic 0 selects a write operation.

7.2 Command register

Following the successful acknowledgement of the slave address + R/W bit, the bus master

will send a byte to the PCA9506, which will be stored in the Command register.

OE

30

23

I

active LOW output enable input

INT

55

48

O

active LOW interrupt output

RESET

56

49

I

active LOW reset input

Table 2:

Symbol

Pin

Type

Description

TSSOP56

HVQFN56

Fig 5.

PCA9506 address

002aab494

0

1

0

0

A2

A1

A0 R/W

fixed

slave address

programmable

Fig 6.

Command register

002aab495

1

0

0

0

0

0

0

0

AI

−

D5

D4

D3

D2

D1

D0

Auto-Increment

register number

default at power-up

or after RESET