LTC3883 Datasheet, PDF (29/112 Pages) Linear Technology – Single Phase Step-Down DC/DC Controller with Digital Power System Management

LTC3883/LTC3883-1
OPERATION
The data formats implemented by PMBus are:
n _{Master transmitter transmits to slave receiver. The}
transfer direction in this case is not changed.
n _{Master reads slave immediately after the first byte. At}
the moment of the first acknowledgment (provided by
the slave receiver) the master transmitter becomes a
master receiver and the slave receiver becomes a slave
transmitter.
n _{Combined format. During a change of direction within}
a transfer, the master repeats both a start condition
and the slave address but with the R/W bit reversed.
In this case, the master receiver terminates the transfer
by generating a NACK on the last byte of the transfer
and a STOP condition.
Examples of these formats are shown in Figures 7-16.
Table 1. Data Format Terminology
PMBus
TERMINOLOGY
Linear
Linear (for Voltage
Related Commands)
Direct
Hex
ASCII
MEANING
Linear
Linear
Direct-Manufacturer
Customized
Register Fields
TERMINOLOGY FOR: SPECS,
GUI, APPLICATION NOTES
Linear_5s_11s
Linear_16u
ABBREVIATIONS FOR
SUMMARY COMMAND TABLE
L11
L16
FOR MORE DETAIL REFER TO
THE DATA FORMAT SECTION
OF TABLE 2
Page 35
Page 35
DirectMfr
CF
Page 35
Hex
I16
ASCII
ASC
Reg
Reg
1
7
11
8
1
S SLAVE ADDRESS Wr A COMMAND CODE A
8
DATA BYTE
Figure 7. Write Byte Protocol
11
AP
3883 F07
1
7
11
8
1
8
1
8
11
S SLAVE ADDRESS Wr A COMMAND CODE A DATA BYTE LOW A DATA BYTE HIGH A P
3883 F08
Figure 8. Write Word Protocol
1
7
11
8
1
8
1
8
S SLAVE ADDRESS Wr A COMMAND CODE A DATA BYTE A
PEC
Figure 9. Write Byte Protocol with PEC
11
AP
3883 F09
1
7
11
8
1
8
1
8
1
S SLAVE ADDRESS Wr A COMMAND CODE A DATA BYTE LOW A DATA BYTE HIGH A
Figure 10. Write Word Protocol with PEC
8
PEC
11
AP
3883 F10
3883f
29