PCF8591 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 7 — 27 June 2013 13 of 31
NXP Semiconductors
PCF8591
8-bit A/D and D/A converter
Eight different I
2
C-bus slave addresses can be used to address the PCF8591 (see
Table 5
).
The least significant bit of the slave address byte is bit R/W (see Table 6).
Bit 1 to bit 3 of the slave address are defined by connecting the input pins A0 to A2 to
either V
SS
(logic 0) or V
DD
(logic 1). Therefore, eight instances of PCF8591 can be
distinguished on the same I
2
C-bus.
Table 5. I
2
C slave address byte
Slave address
Bit 7 6 5 4 3 2 1 0
MSB LSB
slave address 1 0 0 1 A2 A1 A0 R/W
Table 6. R/W-bit description
R/W Description
0 write data
1 read data
Fig 15. Bus protocol for write mode, D/A conversion
Fig 16. Bus protocol for read mode, A/D conversion
0
mbl833
S ADDRESS CONTROL BYTE DATA BYTE
acknowledge
from PCF8591
A
acknowledge
from PCF8591
A A P/S
acknowledge
from PCF8591
N = 0 to M
data bytes
1
mbl834
S ADDRESS DATA BYTE LAST DATA BYTE
acknowledge
from PCF8591
A
acknowledge
from master
A 1 P
no acknowledge
N = 0 to M
data bytes
