Datasheet

LTC2974
20
2974fc
For more information www.linear.com/LTC2974
Table 1. LTC2974 Address Look-Up Table with MFR_I2C_BASE_ADDRESS Set to 7bit 0x5C
DESCRIPTION
HEX DEVICE
ADDRESS BINARY DEVICE ADDRESS ADDRESS PINS
7-Bit 8-Bit 6 5 4 3 2 1 0 R/W ASEL1 ASEL0
Alert Response 0C 19 0 0 0 1 1 0 0 1 X X
Global 5B B6 1 0 1 1 0 1 1 0 X X
N = 0 5C* B8 1 0 1 1 1 0 0 0 L L
N = 1 5D BA 1 0 1 1 1 0 1 0 L NC
N = 2 5E BC 1 0 1 1 1 1 0 0 L H
N = 3 5F BE 1 0 1 1 1 1 1 0 NC L
N = 4 60 C0 1 1 0 0 0 0 0 0 NC NC
N = 5 61 C2 1 1 0 0 0 0 1 0 NC H
N = 6 62 C4 1 1 0 0 0 1 0 0 H L
N = 7 63 C6 1 1 0 0 0 1 1 0 H NC
N = 8 64 C8 1 1 0 0 1 0 0 0 H H
H = Tie to V
DD33
, NC = No Connect = Open or Float, L = Tie to GND, X = Don’t Care
*MFR_I2C_BASE_ADDRESS = 7bit 0x5C (Factory Default)
operaTion
SLAVE ADDRESS COMMAND CODE DATA BYTEWr A A A P
2974 F03
S
7 8 81 1 1 1 11
SLAVE ADDRESS COMMAND CODE DATA BYTE LOWWr A A A P
2974 F04
S
7 8 8 1
DATA BYTE HIGH
81 1 1 1 11
A
SLAVE ADDRESS COMMAND CODE DATA BYTEWr A A A P
2974 F05
S
7 8 8 1
PEC
81 1 1 1 11
A
Figure 3. Write Byte Protocol
Figure 2. PMBus Packet Protocol Diagram Element Key
Figure 4. Write Word Protocol
Figure 5. Write Byte Protocol with PEC
SLAVE ADDRESS DATA BYTEWr A A P
2974 F02
S
7
S START CONDITION
Sr REPEATED START CONDITION
Rd READ (BIT VALUE OF 1)
Wr WRITE (BIT VALUE OF 0)
x SHOWN UNDER A FIELD INDICATES THAT THAT
FIELD IS REQUIRED TO HAVE THE VALUE OF x
A ACKNOWLEDGE (THIS BIT POSITION MAY BE 0
FOR AN ACK OR 1 FOR A NACK)
P STOP CONDITION
PEC PACKET ERROR CODE
MASTER TO SLAVE
SLAVE TO MASTER
CONTINUATION OF PROTOCOL
81 1 1
x x
11
...