Datasheet

PMBus 6-Channel Power-Supply Manager
MAX34440
16 Maxim Integrated
Address Select
On device power-up, the device samples the A0 and A1
pins to determine the PMBus/SMBus serial-port address.
SMBus/PMBus Operation
The device implements the PMBus command structure
using the SMBus format. The structure of the data flow
between the host and the slave is shown below for sev-
eral different types of transactions. Data is sent most
significant bit (MSB) first.
Table 2. PMBus/SMBus Serial-Port Address
KEY:
S = START
Sr = REPEATED START
P = STOP
W = WRITE BIT (0)
R = READ BIT (1)
A = ACKNOWLEDGE (0)
NA = NOT ACKNOWLEDGE (1)
SHADED BLOCK = SLAVE TRANSACTION
SMBus/PMBus Communication Examples
Note: The MAX34440 will also respond to a slave address of
34h (this is the factory programming address) and the device
should not share the same I
2
C bus with other devices that use
this slave address.
A1 A0
7-BIT SLAVE
ADDRESS
100kI to V
SS
100kI to V
SS
1101 010 (D4h)
100kI to V
DD
1101 011 (D6h)
100kI to V
DD
100kI to V
SS
1101 100 (D8h)
100kI to V
DD
1101 101 (DAh)
READ WORD FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A Sr
SLAVE
ADDRESS
R A
DATA BYTE
LOW
A
DATA BYTE
HIGH
NA P
READ BYTE FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A Sr
SLAVE
ADDRESS
R A DATA BYTE NA P
WRITE WORD FORMAT
1 7 1 1 8 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A
DATA BYTE
LOW
A
DATA BYTE
HIGH
A P
WRITE BYTE FORMAT
1 7 1 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A DATA BYTE A P
SEND BYTE FORMAT
1 7 1 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A P