GE
Data Sheet
April 13, 2017
CAR2548DC series dc-dc converter
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
Features
3 front panel LEDs: 1-input;2-output; 3 - fault
Output programmable from 43.2 – 56Vdc
Remote ON/OFF control of the 48Vdc output
Remote sense (up to 0.25V) on the 48Vdc output
No minimum load requirements
Redundant parallel operation
Active load sharing (single wire)
Efficiency: typically 91%
Standby orderable either as 3.3Vdc or 5Vdc
Auto recoverable OC & OT protection
Operating temperature: -10 - 70C
(de-rated above 50C)
Digital status & control: I2C and PMBus serial bus
EN/IEC/UL60950-1 2nd edition; UL, CSA and VDE
EMI: class B FCC docket 20780 part 15, EN55022
Meets EN6100 immunity and transient standards
Shock & vibration: NEBS GR-63-CORE, level 3
Applications
48Vdc distributed power architectures
Cellular Base Stations
Satellite Hubs
Network Equipment
Network Attached Storage
Telecom Access Nodes
Routers/Switches/ATE Equipment
Description
The CAR2548DC series of DC-DC Converters provide highly efficient isolated power from DC input mains in a compact
1U industry standard form factor in an unprecedented power density of 27W/in3. These converters complement the
CAR2548FP rectifier providing comprehensive solutions for systems connected either to commercial ac mains,
48/60Vdc power plants or telecom central offices. This plug and play approach offers significant advantages since
systems can be reconfigured and repositioned readily by simply replacing the power supply. The high-density, front-
to-back airflow is designed for minimal space utilization and is highly expandable for future growth. The industry
standard PMBus compliant I2C communications buss offers a full range of control and monitoring capabilities. The
SMBusAlert signal pin alerts customers automatically of any state change within the power supply.
* UL is a registered trademark of Underwriters Laboratories, Inc.
† CSA is a registered trademark of Canadian Standards Association.
‡ VDE is a trademark of Verband Deutscher Elektrotechniker e.V.
§ Intended for integration into end-user equipment. All the required procedures for CE marking of end-user equipment should be followed. (The CE mark is placed on selected products.)
** ISO is a registered trademark of the International Organization of Standards.
+ PMBus name and logo are registered trademarks of the System Management Interface Forum (SMIF)
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 2
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings
only, functional operation of the device is not implied at these or any other conditions in excess of those given in the operations
sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect the device reliability.
Parameter
Symbol
Min
Max
Unit
Input Voltage: Continuous
VIN
0
75
Vac
Operating Ambient Temperature
TA
-10
701
°C
Storage Temperature
Tstg
-40
85
°C
I/O Isolation voltage (100% factory Hi-Pot tested)
1500
VDC
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, load, and temperature conditions.
INPUT
Parameter
Symbol
Min
Typ
Max
Unit
Operational Range
VIN
-36
-48/60
-75
VDC
48Vdc output turned OFF
-36
48Vdc output turned ON
-42
-45
-48
Idling Power, 48Vdc output OFF
W
35
W
48Vdc output ON
45
Maximum Input Current (VIN= 37.5Vdc, VO= VO, set, IO=IO, max)
IIN
75
ADC
Cold Start Inrush Current (Excluding x-caps, 25C, <10ms,
per ETSI 300-132)
IIN
75
APEAK
Efficiency (Tamb=25C, Vin= -48Vdc, Vout= 48Vdc); 100% load
90
91
87
%
30 – 50% load
20% load
Holdup time2 (Vin= -48Vdc, Vout= 48Vdc, Tamb 25C, IO=IO, max)
T
4
ms
Loss of Output Early Warning Signal
T
1
ms
Isolation; Input/Output
1500
VDC
Input/Frame
1500
VDC
Output/Frame
1000
VDC
Input capacitance
F
25
µf
48VDC MAIN OUTPUT
Parameter
Symbol
Min
Typ
Max
Unit
Output power
POUT
0
2500
W
Set point, @ 50% load
VOUT
47.5
48.00
48.5
VDC
Overall regulation (load, temperature, aging)
-2
+2
%
Linear droop, NL to FL
0.1
VDC
Remote sense (sum of hot & return)
0.25
VDC
Ripple and noise3
500
mVp-p
1
Derated above 50C at 2.5%/C
2
Full load w/5,000µf external output capacitance, Output may droop down to 44Vdc.
3
Measured across a 10µf tantalum and a 0.1µf ceramic capacitors in parallel. 20MHz bandwidth
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 3
48VDC MAIN OUTPUT (continued)
Parameter
Symbol
Min
Typ
Max
Unit
Turn-ON overshoot
VOUT
3
%
Turn-ON delay
T
2
sec
Remote ON/OFF delay time
40
ms
Turn-ON rise time (10 – 90% of VOUT)
50
ms
Transient response 50% step [10%-60%, 50% - 100%]
(dI/dt – 1A/µs, recovery 300µs)
VOUT
-2
+2
VDC
Programmable range (hardware & software)
43.2
56
VDC
Overvoltage protection, latched4
(recover by cycling OFF/ON via hardware or software)
58
59
60
VDC
Output current, Vout= 48Vdc
IOUT
0
52
ADC
Power limit, Vout = 48 to 56Vdc
POUT
2500
W
Current limit, Hiccup (programmable level)
IOUT
105
130
% of FL
Active current share
-5
+5
% of FL
External capacitance
0
5,0005
µf
STANDBY OUTPUT
Parameter
Symbol
Min
Typ
Max
Unit
Set point
Vout
3.3 / 5.0
Vdc
Overall regulation (load, temperature, aging)
Vout
-5
+5
%
Ripple and noise
50
mVp-p
Output current
Iout
0
1
Adc
General Specifications
Parameter
Min
Typ
Max
Units
Notes
Reliability, at 25C
50C
250,000
100,000
Hours
Full load, ; MTBF per SR232 Reliability protection
for electronic equipment, method I, case III,
Service Life
10
Years
Full load, excluding fans
Weight
Kgs/ (Lbs)
Feature Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature conditions. See
Feature Descriptions for additional information.
Parameter
Symbol
Min
Typ
Max
Unit
Remote ON/OFF (Needs to be pulled HI via an external resistor)
Logic High (Module ON)
IIH
20
µA
VIH
0.7VDD
12
VDC
Logic Low (Module OFF)
IIL
1
mA
VIL
0
0.8
VDC
4
The power supply will attempt three restarts prior to latching the shutdown level.
5
4,000µf electrolytic and 1,000µf tantalum capacitors
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 4
Feature Specifications (continued)
Parameter
Symbol
Min
Typ
Max
Unit
Output Voltage programming (Vprog)
Equation: Vout = 10.8 + (Vprog * 0.96)
Vprog range
Vprog
0
2.5
VDC
Programmed output voltage range
Vo
10.8
13.2
VDC
Voltage adjustment resolution (8-bit A/D)
Vo
10
mVDC
Output configured to 13.2Vdc
Vprog
2.5
3.0
VDC
Output configured to the 12Vdc set-point
Vprog
3.0
VDC
Enable [short pin controlling presence of the 12VDC output]
12V output OFF
VI
0.7VDD
12
VDC
12V output ON
VI
0
0.4
VDC
Write protect (Wp)
Write protect enabled
VI
0.7VDD
12
VDC
Write protect disabled
VI
0
0.8
VDC
INPUT-OK (Needs to be pulled HI via an external resistor)
Logic High (Input within normal range)
IOH
20
µA
VOH
0.7VDD
12
VDC
Logic Low (Input out of range)
IOL
20
mA
VOL
0
0.4
VDC
DC-OK ( Internally connected to 3.3V via a 10kΩ resistor)
Logic High (Output voltage is present)
IOH
20
µA
VOH
0.7VDD
12
VDC
Logic Low (Output voltage is not present)
IOL
20
mA
VOL
0
0.4
VDC
Over Temperature Warning (Needs to be pulled HI via an external
resistor)
Logic High (temperature within normal range)
IOH
20
µA
VOH
0.7VDD
12
VDC
Logic Low (temperature is too high)
IOL
20
mA
VOL
0
0.4
VDC
Delayed shutdown after Logic Low transition
Tdelay
10
sec
Fault (Needs to be pulled HI via an external resistor)
Logic High (No fault is present)
IOH
20
µA
VOH
0.7VDD
12
VDC
Logic Low (Fault is present)
IOL
20
mA
VOL
0
0.4
VDC
PS Present (Needs to be pulled HI via an external resistor)
Logic High (Power supply is not plugged in)
IIL
4
mA
Logic Low (Power supply is present)
VIL
0
0.1
VDC
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 5
Feature Specifications (continued)
Parameter
Symbol
Min
Typ
Max
Unit
SMBAlert# (Interrupt) (Needs to be pulled HI via an external
resistor)
Logic High (No Alert - normal)
IOH
20
µA
VOH
0.7VDD
12
VDC
Logic Low (Alert is set)
IOL
20
mA
VOL
0
0.4
VDC
Output current monitor (Imon)
Resolution
100
mV/A
Accuracy
-5
5
% of FL
Measurement range
Io
0
52
ADC
Analog output range
Vmon
0
5.2
VDC
Sourced output current
5
mADC
Digital Interface Specifications
Parameter
Conditions
Symbol
Min
Typ
Max
Unit
PMBus Signal Interface Characteristics
Input Logic High Voltage (CLK, DATA)
VIH
2.1
3.6
VDC
Input Logic Low Voltage (CLK, DATA)
VIL
0
0.8
VDC
Input high sourced current (CLK, DATA)
IIH
0
10
μA
Output Low sink Voltage (CLK, DATA, SMBALERT#)
IOUT=3.5mA
VOL
0.4
VDC
Output Low sink current (CLK, DATA, SMBALERT#)
IOL
3.5
mA
Output High open drain leakage current
(CLK,DATA, SMBALERT#)
VOUT=3.6V
IOH
0
10
μA
PMBus Operating frequency range
Slave Mode
FPMB
10
400
kHz
Measurement System Characteristics
Clock stretching
tSTRETCH
25
ms
IOUT measurement range
Linear
IRNG
0
52
ADC
IOUT measurement accuracy 25°C
IACC
-3
+3
% of FL
VOUT measurement range
Linear
VOUT(rng)
0
60
VDC
VOUT measurement accuracy
VOUT(acc)
-3
+3
%
Temp measurement range
Linear
Temp(rng)
0
120
C
Temp measurement accuracy6
Temp(acc)
-5
+5
C
IIN measurement range
Linear
IIN(rng)
0
80
ADC
IIN measurement accuracy
IIN(acc)
-5
+5
%
VIN measurement range
Linear
VIN(rng)
0
80
VDC
VIN measurement accuracy
VIN(acc)
-3
+3
%
PIN measurement range
Linear
PN(rng)
0
3000
W
PIN measurement accuracy
PIN(acc)
-5
+5
%
Fan Speed measurement range
Linear
0
30k
RPM
Fan Speed measurement accuracy
-5
5
%
Fan speed control range
-direct-
0
100
%
6
Temperature accuracy reduces non-linearly with decreasing temperature
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 6
Environmental Specifications
Parameter
Min
Typ
Max
Units
Notes
Ambient Temperature
-107
70
°C
Derated above 50C
Storage Temperature
-40
85
°C
Operating Altitude
2250/7382
m/ft
Non-operating Altitude
8200/30k
m / ft
Power Derating with Temperature
2.5
%/°C
50C to 70C
Power Derating with Altitude
2.0
C/301 m
C/1000 ft
Above 2250 m/7382 ft
Acoustic noise
55
dbA
25C, half load
Over Temperature Protection
110/95
°C
Shutdown / restart
Humidity
Operating
Storage
30
10
95
95
%
Relative humidity, non-condensing
Shock and Vibration acceleration
6
Grms
NEBS GR-63-CORE, Level 3, 20 -
2000Hz, min 30 minutes
Earthquake Rating
4
Zone
NEBS GR-63-CORE, all floors, Seismic
Zone 4 Designed and tested to meet
NEBS specifications.
EMC Compliance
Parameter
Criteria
Standard
Level
Test
DC input
Conducted emissions
EN55022, FCC Docket 20780 part 15,
subpart J
A8
0.15 – 30MHz
Radiated emissions9
EN55022
A
30 – 10000MHz
DC INPUT
immunity
Voltage dips
EN61000-4-11
B
-30%, 10ms
B
-60%, 100ms
B
-100%, 5sec
Voltage surge
EN61000-4-5, level 4
A
4kV, 1.2/50µs, common mode
A
2kV, 1.2/50µs, differential
mode
Fast transients
EN61000-4-4, level 3
B
5/50ns, 2kV (common mode)
Enclosure
immunity
Conducted RF fields
EN61000-4-6, level 3
A
130dBµV, 0.15-80MHz, 80%
AM
Radiated RF fields
EN61000-4-3, level 3
A
10V/m, 80-1000MHz, 80% AM
ENV50140
A
ESD
EN61000-4-2, level 3
B
6kV contact, 8kV air
7
Designed to start at an ambient down to -40°C; meet spec after 30 min warm up period, may not meet operational limits below -10°C.
8
Class B EMI conducted and radiated levels met with an external filter. Please contact sales for a recommended filter.
9
Radiated emissions compliance is contingent upon the final system configuration.
GE
Data Sheet
CAR2548DC series dc-dc converters
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 7
Control and Status
Control hierarchy: Some features, such as output voltage,
can be controlled both through hardware and firmware. For
example, the output voltage is controlled both by the signal pin
(Vprog) and the PMBus command, (Vout_command) .
Using output voltage as an example; the Vprog signal pin has
ultimate control of the output voltage until the Vprog is either >
3Vdc or a no connect. When the programming signal via Vprog
is either a no connect or > 3Vdc, it is ignored, the output
voltage is set at its nominal 12Vdc and the unit output voltage
can be controlled via the PMBus command, (Vout_command).
Analog controls: Details of analog controls are provided in
this data sheet under Signal Definitions.
Common ground: All signals and outputs are referenced to
Output return. These include ‘Vstb return’ and ‘Signal return’.
Control Signals
Voltage programming (Vprog): An analog voltage on this
signal can vary the output voltage from 43.2Vdc to
56Vdc. The equation of this signal is:
Vout = 42.67 + (Vprog * 5.33) where Vprog = 0.1 to 2.5V
For Vprog > 2.5V the output reverts back to 48Vdc.
Load share (Ishare): This is a single wire analog signal that is
generated and acted upon automatically by power supplies
connected in parallel. The Ishare pins should be tied together
for power supplies if active current share among the power
supplies is desired. No resistors or capacitors should get
connected to this pin.
Able to current share with CAR2548FP rectifiers.
Remote_ON/OFF: Controls presence of the 48Vdc output
voltage. This is an open collector, TTL level control signal that
needs to be pulled HI externally through a resistor.
A turn OFF command either through this signal (Remote
ON/OFF) or firmware commanded would turn OFF the 48V
output.
Enable: This is a short signal pin that controls the presence of
the 48Vdc main output. This pin should be connected to
‘output return’ on the system side of the output connector. The
purpose of this pin is to ensure that the output turns ON after
engagement of the power blades and turns OFF prior to
disengagement of the power blades.
Write protect (WP): This signal protects the contents of the
EEPROM from accidental over writing. When left open the
EEPROM is write protected. A LO (TTL compatible) permits
writing to the EEPROM. This signal is pulled HI internally by the
power supply.
Status signals
Output current monitor (Imon): A voltage level proportional to
the delivered output current is present on this pin. The signal
level is 0.1V per amp ± 0.25V.
Input_OK: A TTL compatible status signal representing
whether the input voltage is within the anticipated range. This
signal needs to be pulled HI externally through a resistor.
DC_OK: A TTL compatible status signal representing whether
the output voltage is present. This signal needs to be pulled HI
externally through a resistor.
Over_temp_warning: A TTL compatible status signal
representing whether an over temperature exists. This signal
needs to be pulled HI externally through a resistor.
If an over temperature should occur, this signal would pull LO
approximately 10 seconds prior to shutting down the power
supply. The unit would restart if internal temperatures recover
within normal operational levels. At that time the signal reverts
back to its open collector (HI) state.
Fault: A TTL compatible status signal representing whether a
Fault occurred. This signal needs to be pulled HI externally
through a resistor.
This signal activates for OTP, OVP, OCP, INPUT fault or No
output.
PS_Present: This pin is connected to ‘output return’ within the
power supply. Its intent is to indicate to the system that a
power supply is present. This signal may need to be pulled HI
externally through a resistor.
Interrupt (SMBAlert): A TTL compatible status signal,
representing the SMBusAlert# feature of the PMBus compatible
i2C protocol in the power supply. This signal needs to be pulled
HI externally through a resistor.
Serial Bus Communications
The I²C interface facilitates the monitoring and control of
various operating parameters within the unit and transmits
these on demand over an industry standard I²C Serial bus.
All signals are referenced to ‘Signal Return’.
Device addressing: The microcontroller (MCU) and the EEPROM
have the following addresses:
Device
Address
Address Bit Assignments
(Most to Least Significant)
MCU
0xBx
1
0
1
1
A2
A1
A0
R/W
Broadcast
0x00
0
0
0
0
0
0
0
0
EEPROM
0xAx
1
0
1
0
A2
A1
A0
R/W
The Global Broadcast instruction executes a simultaneous
write instruction to all power supplies. A read instruction
cannot be accessed globally. The three programmable address
bits are the same for all I2C accessible devices within the
power supply.
Address lines (A2, A1, A0): These signal pins allow up to eight
(8) modules to be addressed on a single I²C bus. The pins are
pulled HI internal to the power supply. For a logic LO these pins
should be connected to ‘Output Return’
Serial Clock (SCL): The clock pulses on this line are generated
by the host that initiates communications across the I²C Serial
bus. This signal is pulled up internally to 3.3V by a 10kΩ
resistor. The end user should add additional pull up resistance
as necessary to ensure that rise and fall time timing and the
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 8
maximum sink current is in compliance to the I²C
specifications.
Serial Data (SDA): This line is a bi-directional data line. . This
signal is pulled up internally to 3.3V by a 10kΩ resistor. The end
user should add additional pull up resistance as necessary to
ensure that rise and fall time timing and the maximum sink
current is in compliance to the I²C specifications.
Digital Feature Descriptions
PMBus™ compliance: The power supply is fully compliant to
the Power Management Bus (PMBus™) rev1.2 requirements.
Manufacturer specific commands located between addresses
0xD0 to 0xEF provide instructions that either do not exist in the
general PMBus specification or make the communication
interface simpler and more efficient.
Master/Slave: The ‘host controller’ is always the MASTER.
Power supplies are always SLAVES. SLAVES cannot initiate
communications or toggle the Clock. SLAVES also must
respond expeditiously at the command of the MASTER as
required by the clock pulses generated by the MASTER.
Clock stretching: The ‘slave’ µController inside the power
supply may initiate clock stretching if it is busy and it desires to
delay the initiation of any further communications. During the
clock stretch the ‘slave’ may keep the clock LO until it is ready
to receive further instructions from the host controller. The
maximum clock stretch interval is 25ms.
The host controller needs to recognize this clock stretching,
and refrain from issuing the next clock signal, until the clock
line is released, or it needs to delay the next clock pulse
beyond the clock stretch interval of the power supply.
Note that clock stretching can only be performed after
completion of transmission of the 9th ACK bit, the exception
being the START command.
Figure 1. Example waveforms showing clock stretching.
I²C Bus Lock-Up detection: The device will abort any
transaction and drop off the bus if it detects the bus being held
low for more than 35ms.
Communications speed: Both 100kHz and 400kHz clock rates
are supported. The power supplies default to the 100kHz clock
rate. The minimum clock speed specified by SMBus is 10 kHz.
Packet Error Checking (PEC): Although the power supply will
respond to commands with or without the trailing PEC, it is
highly recommended that PEC be used in all communications.
The integrity of communications is compromised if packet
error correction is not employed. There are many functional
features, including turning OFF the main output, that should
require validation to ensure that the correct command is
executed.
PEC is a CRC-8 error-checking byte, based on the polynomial
C(x) = x8 + x2 + x + 1, in compliance with PMBus™
requirements. The calculation is based in all message bytes,
including the originating write address and command bytes
preceding read instructions. The PEC is appended to the
message by the device that supplied the last byte.
SMBAlert#: The µC driven SMBAlert# signal informs the
‘master/host’ controller that either a STATE or ALARM change
has occurred. Normally this signal is HI. The signal will change
to its LO level if the power supply has changed states and the
signal will be latched LO until the power supply either receives
a ‘clear’ instruction as outlined below or executes a READ
STATUS_WORD. If the alarm state is still present after the
STATUS registers were reset, then the signal will revert back
into its LO state again and will latch until a subsequent reset
signal is received from the host controller.
The signal will be triggered for any state change, including the
following conditions;
VIN under or over voltage
Vout under or over voltage
IOUT over current
Over Temperature warning or fault
Fan Failure
Communication error
PEC error
Invalid command
Detected internal faults
The power supply will clear the SMBusAlert# signal (release the
signal to its HI state) upon the following events:
Receiving a CLEAR_FAULTS command
The main output recycled (turned OFF and then ON) via
the ENABLE signal pin
The main output recycled (turned OFF and then ON) by the
OPERATION command
Execution of a READ of the STATUS_WORD register
Global broadcast: This is a powerful command because it can
instruct all power supplies to respond simultaneously in one
command. But it does have a serious disadvantage. Only a
single power supply needs to pull down the ninth acknowledge
bit. To be certain that each power supply responded to the
global instruction, a READ instruction should be executed to
each power supply to verify that the command properly
executed. The GLOBAL BROADCAST command should only be
executed for write instructions to slave devices.
Read back delay: The power supply issues the SMBAlert #
notification as soon as the first state change occurred. During
an event a number of different states can be transitioned to
before the final event occurs. If a read back is implemented
rapidly by the host a successive SMBAlert# could be triggered
by the transitioning state of the power supply. In order to avoid
successive SMBAlert# s and read back and also to avoid
reading a transitioning state, it is prudent to wait more than 2
seconds after the receipt of an SMBAlert# before executing a
read back. This delay will ensure that only the final state of the
power supply is captured.
Successive read backs: Successive read backs to the power
supply should not be attempted at intervals faster than every
one second. This time interval is sufficient for the internal
Clock
Stretch
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 9
processors to update their data base so that successive reads
provide fresh data.
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.
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 communications: 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 Error! Reference source not found. write any
number of bytes greater than two.
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
MV 2
Where: V is the value, M is the 11-bit, two’s omplement
mantissa, E is the 5-bit, two’s complement exponent
PMBusTM 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
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 10
Command
Hex
Code
Data
Field
Function
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
Status_CML
7E
1
Status_other
7F
1
Status_mfr_specific
80
1
Status_fan_1_2
81
1
Read_Vout
8B
2
Read output voltage
Read_Iout
8C
2
Read output current
Read_temperature
8D
2
Read Temperature
Read_Pout
96
2
PMBus revision
98
1
Mfr_ID
99
5
FRU_ID
Mfr_model
9A
15
Mfr_revision
9B
4
Mfr_location
9C
4
Mfr_date
9D
6
Mfr_serial
9E
15
Mfr_Vin_min
A0
2
36V (linear format)
Mfr_Vin_max
A1
2
75V (linear format)
Mfr_Iin_max
A2
2
27A (linear format)
Mfr_Pin_max
A3
2
950W (linear format)
Mfr_Vout_min
A4
2
10V (linear format)
Mfr_Vout_max
A5
2
15V (linear format)
Mfr_Iout_max
A6
2
71A (linear format)
Mfr_Pout_max
A7
2
850W (linear format)
Mfr_Tambient_max
A8
2
70C (linear format)
Mfr_Tambient_min
A9
2
-10C (linear format)
User_data_00
B0
48
User memory space
User_data_01
B1
48
User memory space
FRW_revision
D0
1
Ilimit_control_I2C
D3
2
Ilimit set (1/100A)
Vout_control_ I2C
D4
2
Vout set (1/512V)
Fan_duty_cycle
D6
1
Duty_cycle in %
Fan_speed
D7
1
Control in duty cycle
Vprog_ext
D8
2
Read_Vout_ I2C
E0
2
1/512V
Read_Iout_ I2C
E1
2
1/100A
Read_TS_ I2C
E2
2
Heat sink temp C
CMD_OFF_ I2C
E3
2
01-OFF, 00-ON
OTF_limit_ I2C
E4
2
OT fault limit C
OTF_recovery_ I2C
E5
2
OT fault recovery C
DCOKHI_ I2C
E6
2
High OV fault (1/512V)
DCOKLO_ I2C
E7
2
Low OV fault (1/512V)
Status Register Bit Allocation:
Register
Code
Bit
Function
Status_Byte
78
7
Busy
6
DC_ OFF
5
Output OV Fault detected
4
Output OC Fault detected
3
Input UV Fault detected
2
Temperature Fault/warning
detected
1
CML (communication fault)
detected
0
None of Below
Status_word
(includes Status_byte)
79
7
OV Fault/Warning detected
6
OC Fault/Warning detected
5
Input Fault/Warning detected
4
Mfr_specific register change
detected
3
DC_OFF
2
Fan Fault or Warning
detected
1
Other fault
0
Unknown
Status_Vout
7A
7
Vout OV Fault
6
Vout OV Warning
5
Vout UV Warning
4
Vout UV Fault
3
N/A
2
N/A
1
N/A
0
N/A
Status_Iout
7B
7
IOUT OC Fault
6
N/A
5
IOUT OC Warning
4
N/A
3
N/A
2
N/A
1
N/A
0
N/A
Status_input
7C
7
Vin OV Fault
6
Vin OV Warning
5
Vin UV Warning
4
Vin UV Fault
3
N/A
2
N/A
1
N/A
0
N/A
Status_temperature
7D
7
OT Fault
6
OT Warning
5
N/A
4
N/A
3
N/A
2
N/A
1
N/A
0
N /A
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 11
Register
Code
Bit
Function
Status_cml
7E
7
Invalid/Unsupported
Command
6
Invalid/Unsupported Data
5
Packet Error Check Failed
4
Memory Fault Detected
3
Processor Fault Detected
2
Reserved
1
Other Communications Fault
0
Other Memory or Logic Fault
Status_mfr_specif
ic
80
7
3.3V_fault
6
N/A
5
Interrupt
4
Fault detected
3
PS_remote_OFF
2
DC_fault
1
INPUT_fault
0
N/A
Command Descriptions
Operation (01) : By default the Power supply is turned ON at
power up as long as Power ON/OFF signal pin is active HI. The
Operation command is used to turn the Power Supply ON or
OFF via the PMBus. The data byte below follows the
OPERATION command.
FUNCTION
DATA BYTE
Unit ON
80
Unit OFF
00
To RESET the power supply cycle the power supply OFF, wait at
least 2 seconds, and then turn back ON. All alarms and
shutdowns are cleared during a restart.
Clear_faults (03): This command clears all STATUS and FAULT
registers and resets the SMBAlert# line.
If a fault still persists after the issuance of the clear_faults
command the specific registers indicating the fault are reset
and the SMBAlert# line is activated again.
WRITE_PROTECT register (10): Used to control writing to the
PMBus device. The intent of this command is to provide
protection against accidental changes. All supported
command parameters may have their parameters read,
regardless of the write_protect settings. The contents of this
register can be stored to non-volatile memory using the
Store_default_code command. The default setting of this
register is disable_all_writes except write_protect 0x80h.
FUNCTION
DATA BYTE
Enable all writes
00
Disable all writes except write_protect
80
Disable all writes except write_protect and
OPERATION
40
Vout_Command (21) : This command is used to change the
output voltage of the power supply. Changing the output
voltage should be performed simultaneously to all power
supplies operating in parallel using the Global Address
(Broadcast) feature. If only a single power supply is instructed
to change its output, it may attempt to source all the required
power which can cause either a power limit or shutdown
condition.
Software programming of output voltage permanently
overrides the set point voltage configured by the Vprog signal
pin. The program no longer looks at the ‘Vprog pin’ and will not
respond to any hardware voltage settings. If power is removed
from the µController it will reset itself into its default
configuration looking at the Vprog signal for output voltage
control. In many applications, the Vprog pin is used for setting
initial conditions, if different that the factory setting. Software
programming then takes over once I2C communications are
established.
To properly hot-plug a power supply into a live backplane, the
system generated voltage should get re-configured into either
the factory adjusted firmware level or the voltage level
reconfigured by the margin pin. Otherwise, the voltage state
of the plugged in power supply could be significantly different
than the powered system.
Vout_OV_warn_limit (42): OV_warning is extremely useful
because it gives the system controller a heads up that the
output voltage is drifting out of regulation and the power
supply is close to shutting down. Pre-amative action may be
taken before the power supply would shut down and
potentially disable the system.
OC and OT_fault_ response (47, 50): The default response for
both OC and OT is auto_restart (hiccup). Each register,
individually, can be reconfigured into a latched state. Latched
and hiccup are the only supported states.
Restart after a latch off: Either of four restart possibilities are
available. The hardware pin Remote ON/OFF may be turned
OFF and then ON. The unit may be commanded to restart via
i2c through the Operation command by first turning OFF then
turning ON . The third way to restart is to remove and reinsert
the unit. The fourth way is to turn OFF and then turn ON ac
power to the unit. The fifth way is by changing firmware from
latch off to restart. Each of these commands must keep the
power supply in the OFF state for at least 2 seconds, with the
exception of changing to restart.
A power system that is comprised of a number of power
supplies could have difficulty restarting after a shutdown event
because of the non-synchronized behavior of the individual
power supplies. Implementing the latch-off mechanism
permits a synchronized restart that guarantees the
simultaneous restart of the entire system.
A synchronous restart can be implemented by;
1. Issuing a GLOBAL OFF and then ON command to all power
supplies,
2. Toggling Off and then ON the Remote ON/OFF signal
3. Removing and reapplying input commercial power to the
entire system.
The power supplies should be turned OFF for at least 20 – 30
seconds in order to discharge all internal bias supplies and
reset the soft start circuitry of the individual power supplies.
Auto_restart: Auto-restart is the default configuration for
recovering from over-current and over-temperature
shutdowns.
An overvoltage shutdown is followed by three attempted
restarts, each restart delayed 1 second, within a 1 minute
window. If within the 1 minute window three attempted
restarts failed, the unit will latch OFF. If less than 3 shutdowns
occur within the 1 minute window then the count for latch OFF
resets and the 1 minute window starts all over again.
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 12
Vin_UV_warn_limit (58): This is another warning flag
indicating that the input voltage is decreasing dangerously
close to the low input voltage shutdown level.
Status_word (79): returns two bytes of information. The upper
byte bit functionality is tabulated in the Status_word section.
The lower byte bit functionality is identical to Status_byte.
Fan_speed (D7): This register can be used to ‘read’ the fan
speed in adjustment percent (0 – 100%) or set the fan speed in
adjustment percent (0 – 100%). The speed of the fan cannot
be reduced below what the power supply requires for its
operation. The register value is the percent number, it is not in
linear format.
Invalid commands or data: The power supply notifies the
MASTER if a non-supported command has been sent or invalid
data has been received. Notification is implemented by setting
the appropriate STATUS and ALARM registers and setting the
SMBAlert# flag.
If a non-supported read is requested the power supply will
return all 0x00h.
Restart after a lachoff: To restart after a latch_off either of
four restart mechanisms are available. The hardware pin
Remote ON/OFF may be turned OFF and then ON. The unit
may be commanded to restart via i2c through the Operation
command by first turning OFF then turning ON . The third way
to restart is to remove and reinsert the unit. The fourth way is
to turn OFF and then turn ON ac power to the unit. The fifth
way is by changing firmware from latch off to restart. Each of
these commands must keep the power supply in the OFF state
for at least 2 seconds, with the exception of changing to
restart.
A successful restart shall clear all alarm registers.
A power system that is comprised of a number of power
supplies could have difficulty restarting after a shutdown event
because of the non-synchronized behavior of the individual
power supplies. Implementing the latch-off mechanism
permits a synchronized restart that guarantees the
simultaneous restart of the entire system.
A synchronous restart can be implemented by;
1. Issuing a GLOBAL OFF and then ON command to all power
supplies,
2. Toggling Off and then ON the Remote ON/OFF signal
3. Removing and reapplying input commercial power to the
entire system.
It is good practice to turn OFF the power supplies for about 20
– 30 seconds in order to discharge all internal bias supplies
and reset the soft start circuitry of the individual power
supplies.
Control and Read accuracy:
The estimates below are believed to be reasonable under most
operating conditions. However, these are typical numbers and
not hard bound values that cannot be exceeded. In most
nominal operating conditions the returned values are
significantly better than these estimates.
FUNCTION
ACCURACY
Vout_command
± 2%
Vout_OV_fault_limit
± 3%
Iout_OC_warn_limit
± 4% of FL
OT_warn_limit
± 5C
Vin_UV_warn_limit
± 3%
Vin_UV_fault_limit
± 3%
Read_Vout
± 2%
Read_Iout
± 4% of FL
Read_temperature
± 5C
Read_Pout
±5%
EEPROM
The microcontroller has 96 bytes of EEPROM memory available
for the system host.
A separate EEPROM IC, with write protect features, provides
another 128 bytes of memory. This EEPROM contains the
following FRU_ID information:
EEPROM: model number, revision, date code, serial number etc.
Offset
Length
Value
Description
00
7
Serial number
07
1
20
ASCII space
08
4
Date code [YY,WW], ASCII numeric value
0C
1
20
ASCII space
0D
17
Model#, ASCII alphanumeric value
1E
1
20
ASCII space
1F
1
Revision, ASCII value
20-FF
224
FF
LEDs
Three LEDs are located on the front faceplate. When the LEDs
are ON GREEN then input and output are normal.
When the FAULT_LED is RED then a fault condition exists and
the power supply may not provide output power. The table
below further defines these states:
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 13
Alarm Table
Test Condition
LED Indicator
Monitoring Signals
INPUT OK
DC OK
FAULT
FAULT
DC OK
INPUT OK
TEMP OK
1
Normal Operation
Green
Green
OFF
High
High
High
High
2
Low or NO INPUT
OFF
OFF
Red
Low
Low
Low
High
3
OVP
Green
OFF
Red
Low
Low
High
High
4
Over Current
Green
OFF
Red
Low
Low
High
High
5
Over Temp Alarm
Green
Green
Red
Low
High
High
Low
6
Over Temp Fault
Green
OFF
Red
Low
Low
High
Low
Note: Test condition #2 has 2 modules working in parallel. One module is running and the other has no iNPUT.
Outline Drawing
Input connector: FCI Berg 51939-311 or TYCO 6450129-3
Input mate: FCI Berg 10080594-1E0101LF10
Output connector: FCI Berg 51939-030
Output mate: FCI Berg 51915-051
10
This is a cable harness with 10 foot of #10ga stranded wire (2 – black and 2 – red) not-terminated on user end
RED LED (FAULT)
Airflow
14.250 ±.020
4.000 ±.020
0.50
0.330
1.610 ±.020
COVER
CHASSIS
POT ADJ.
GREEN LED (DC-OK)
GREEN LED (INPUT-OK)
0.494
1.250
INPUT
CONNECTOR (pin1)
HANDLE
AIR INLET
#10-32
GROUND STUD
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 14
Connector Pin Assignments
Input
Pin
Function
Pin
Function
P1
- DC input
P3
+ DC input
P2
- DC input
P4
+ DC input
Output
Pin
Function
Pin
Function
Pin
Function
Pin
Function
A1
Vstb [3.3V]
B1
Fault
C1
ISHARE
D1
VProg
A2
Vstb [3.3V] Return
B2
I Monitor (IMON)
C2
N/C
D2
OVP Test Point
A3
Signal Return
B3
PS Present
C3
Over Temp Warning
D3
Remote ON/OFF
A4
Write Protect (WP)
B4
Enable
C4
I2C Address (A0)
D4
DC OK
A5
Remote Sense (+)
B5
SDA (I2C bus)
C5
I2C Address (A1)
D5
INPUT OK
A6
Remote Sense (-)
B6
SCL (I2C bus)
C6
I2C Address (A2)
D6
SMBAlert
P1
N/C
P2
N/C
P3
N/C
P4
+Vout
P5
+Vout
P6
Output Return
P7
Output Return
GE
Data Sheet
CAR2548DC series dc-dc converters
Input: -36Vdc to -75Vdc; Output: 48Vdc @ 2500W; 3.3Vdc or 5 Vdc @ 1A
Contact Us
For more information, call us at
USA/Canada:
+1 888 546 3243, or +1 972 244 9288
Asia-Pacific:
+86.021.54279977*808
Europe, Middle-East and Africa:
+49.89.878067-280
http://www.geindustrial.com/products/critical-power
April 13, 2017
©2017 General Electric Company. All rights reserved.
Page 15
Ordering Information
Please contact your GE Sales Representative for pricing, availability and optional features.
PRODUCT
DESCRIPTION
PART NUMBER
2500W converter
48Vdc dc-dc converter w/Bezel, 3.3Vaux
CAR2548DCXXXZ01A
10KW SHELF
Shelf for CAR2548 modules holds 4 units
ACE254RUW48XZ01A
PART NUMBER DEFINITION GUIDE EXAMPLE
CAR 25 48 DC x x x Z 01 A
RTM
RoHS
Blank –non compliant
Y –5 of 6 compliant
Z –6 of 6 compliant
Options
B –bezel
R –reverse airflow
Vsb = 5
Output Power
25 = 2500W
Output voltage
48 = 48Vdc
Type
FP –AC; Vo-positive
TN –AC; Vo_negative
DC - DC
A –Standard
model