Data Sheet
GE
CAR0812DC Series DC-DC Converter
Input: -36VDC to -75VDC; Output: +12 VDC @ 850W; 3.3VDC or 5 VDC @ 1A
processors to update their data base so that successive reads
provide fresh data.
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.
PMBusTM 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.
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.
1
S
8
1
A
8
1
A
Data Byte High
Data Byte Low
Slave address
Wr
Command Code
Bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
Exponent (E)
Mantissa (M)
8
1
A
8
1
A
8
PEC
1
A
1
P
Low data byte
High data byte
The relationship between the Mantissa, Exponent, and Actual
Value (V) is given by the following equation:
Master to Slave
Slave to Master
SMBUS annotations; S – Start , Wr – Write, Sr – re-Start, Rd –
Read,
V M 2E
A – Acknowledge, NA – not-acknowledged, P – Stop
Where:
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.
V is the value
M is the 11-bit, two’s complement mantissa
E is the 5-bit, two’s complement exponent
PMBusTM Command set:
Hex
Code
01
02
03
Data
Byte
1
1
0
1
S
7
1
Wr
1
A
8
1
A
Command
Operation
ON_OFF_config
Clear_faults
Function
Output ON/OFF
09, output ON default
Clear Status
Slave address
Command Code
1
7
1
1
A
8
LSB
1
A
Sr Slave Address
Rd
Write_protect
10
11
12
1
0
0
Write control
8
MSB
1
A
8
PEC
1
1
P
Store_default_all
Store permanently
Reset defaults
No-ack
Restore_default_all
Capability
Vout_mode
Vout_command
19
20
21
40
41
42
43
44
45
46
47
1
1
2
2
1
2
2
2
1
2
1
30h, 400kHz, SMBAlert
Vout constants
Set Vout
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.
Vout_OV_fault_limit
Vout_OV_fault_response
Vout_OV_warn_limit
Vout_UV_warn_limit
Vout_UV_fault_limit
Vout_UV_fault_response
Iout_OC_fault_limit
Iout_OC_fault_response
Set OV fault limit
Block write format:
Set OV warn limit
Set UV warn limit
1
S
7
1
Wr
1
A
8
1
A
Slave address
Command Code
8
1
A
8
1
A
8
1
A
Byte count = N
Data 1
Data 2
Latch or hiccup
8
……….
1
A
8
1
A
8
PEC
1
A
1
P
Set OC warn limit
Iout_OC_warn_limit
OT_fault_limit
4A
4F
50
51
52
53
54
55
57
58
2
2
1
2
2
2
1
2
2
2
Data 48
Latch or hiccup
Set OT warn limit
OT_fault_response
OT_warn_limit
Block read format:
1
S
7
1
1
A
8
1
A
UT_warn_limit
Slave address
Wr
Command Code
UT_fault_limit
1
Sr
7
1
Rd
1
A
UT_fault_response
Vin_OV_fault_limit
Vin_OV_warn_limit
Vin_UV_warn_limit
Slave Address
Set OV warn limit
Set UV warn limit
Set UV shutdown
8
1
A
8
1
A
8
1
A
Byte count = N
Data 1
Data 2
Vin_UV_fault_limit
Status_byte
Status_word
Status_Vout
Status_Iout
59
78
79
7A
7B
7C
7D
2
1
2
1
1
1
1
8
1
A
8
1
A
8
1
1
P
……….
Data 48
PEC
NoAck
Status_input
Status_temperature
April 23, 2013
©2013 General Electric Company. All rights reserved.
Page 11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
