Car0812dc series dc-dc converter, Data sheet, Input: -36v – GE Industrial Solutions CAR0812DC Series User Manual
Page 11: Output: +12 v, Or 5 v, Pmbus, Commands, Command set, Mv 2
GE
Data Sheet
CAR0812DC Series DC-DC Converter
Input: -36V
DC
to -75V
DC
; Output: +12 V
DC
@ 850W; 3.3V
DC
or 5 V
DC
@ 1A
April 23, 2013
©2013 General Electric Company. All rights reserved.
Page 11
processors to update their data base so that successive reads
provide fresh data.
PMBus
TM
Commands
Standard instruction:
Up to two bytes of data may follow an
instruction depending on the required data content. Analog
data is always transmitted as LSB followed by MSB. PEC is
optional and includes the address and data fields.
1 8 1
8 1
S Slave
address Wr A Command
Code A
8 1 8 1
8
1
1
Low data byte
A High
data
byte A PEC A P
Master to Slave Slave to Master
SMBUS annotations; S – Start , Wr – Write, Sr – re-Start, Rd –
Read,
A – Acknowledge, NA – not-acknowledged, P – Stop
Standard READ:
Up to two bytes of data may follow a READ
request depending on the required data content. Analog data
is always transmitted as LSB followed by MSB. PEC is
mandatory and includes the address and data fields
.
PEC is
optional and includes the address and data fields.
1 7
1
1 8 1
S Slave
address Wr A Command
Code A
1 7 1
1 8
1
Sr Slave
Address Rd A
LSB A
8 1 8
1
1
MSB A PEC No-ack
P
Block instruction:
When writing or reading more than two
bytes of data at a time BLOCK instructions for WRITE and READ
commands must be used instead of the Standard Instructions.
Block write format:
1 7 1
1
8 1
S Slave
address Wr A Command
Code A
8 1
8
1
8
1
Byte count = N
A Data
1 A Data
2 A
8 1 8 1 8 1
1
………. A Data
48 A PEC A P
Block read format:
1 7 1
1
8 1
S Slave
address Wr A Command
Code A
1 7 1
1
Sr Slave
Address Rd
A
8 1
8
1
8
1
Byte count = N
A
Data 1
A Data 2
A
8 1 8 1 8 1 1
………. A
Data 48
A
PEC NoAck P
Linear Data Format
The definition is identical to Part II of the
PMBus Specification. All standard PMBus values, with the
exception of output voltage related functions, are represented
by the linear format described below. Output voltage functions
are represented by a 16 bit mantissa. Output voltage has a E=9
constant exponent.
The Linear Data Format is a two byte value with an 11-bit,
two’s complement mantissa and a 5-bit, two’s complement
exponent or scaling factor, its format is shown below.
Data Byte High
Data Byte Low
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
Exponent
(E)
Mantissa
(M)
The relationship between the Mantissa, Exponent, and Actual
Value (V) is given by the following equation:
E
M
V
2
Where:
V is the value
M is the 11-bit, two’s complement mantissa
E is the 5-bit, two’s complement exponent
PMBus
TM
Command set:
Command
Hex
Code
Data
Byte
Function
Operation 01
1
Output
ON/OFF
ON_OFF_config
02
1
09, output ON default
Clear_faults 03
0
Clear
Status
Write_protect 10
1
Write
control
Store_default_all 11
0
Store
permanently
Restore_default_all 12
0
Reset
defaults
Capability
19
1
30h, 400kHz, SMBAlert
Vout_mode 20
1
Vout
constants
Vout_command 21
2
Set
Vout
Vout_OV_fault_limit 40
2
Set OV fault limit
Vout_OV_fault_response 41 1
Vout_OV_warn_limit
42
2
Set OV warn limit
Vout_UV_warn_limit
43
2
Set UV warn limit
Vout_UV_fault_limit 44
2
Vout_UV_fault_response 45 1
Iout_OC_fault_limit 46
2
Iout_OC_fault_response
47 1
Latch or hiccup
Iout_OC_warn_limit 4A
2
Set OC warn limit
OT_fault_limit 4F
2
OT_fault_response 50
1
Latch or hiccup
OT_warn_limit 51
2
Set OT warn limit
UT_warn_limit 52
2
UT_fault_limit 53
2
UT_fault_response 54
1
Vin_OV_fault_limit 55
2
Vin_OV_warn_limit 57
2
Set OV warn limit
Vin_UV_warn_limit
58
2
Set UV warn limit
Vin_UV_fault_limit
59
2
Set UV shutdown
Status_byte 78
1
Status_word 79
2
Status_Vout 7A
1
Status_Iout 7B
1
Status_input 7C
1
Status_temperature 7D
1