GE Industrial Solutions CAR1212DC series - Manual (Page 9)

GE
Data Sheet
CAR1212DC series DC-DC converter
Input: -36V
D C
to -75V
DC
; Output: 12V
DC
@ 1200W; 3.3V
DC
or 5 V
DC
@ 1A
October 21, 2013 ©2013 General Electric Company. All rights reserved. Page 9
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 > 3V
DC
or a no connect. When the programming signal
via Vprog is either a no connect or > 3V
DC
, it is ignored, the
output voltage is set at its nominal 12V
DC
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 10.8V
DC
to 13.2V
DC
. The equation of
this signal is:
V
OUT
= 10.8 + (Vprog * 0.96) where Vprog = 0.1 to 2.5V
Between 2.5 and 3V the output stays at 13.2V
DC
. If Vprog is > 3V, or
left open, the programming signal is ignored and the unit output is
set at the setpoint of 12V
DC
.
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.
Remote ON/OFF: Controls presence of the main 12V
DC
output
voltage on the output connector. This signal is pulled HI internally.
Leaving this pin a no-connect turns ON the 12V
DC
output. Applying a
Logic 0 (TTL LO level) to this pin turns OFF the 12V
DC
output.
A turn OFF command either through this signal (Remote ON/OFF) or
firmware commanded would turn OFF the 12V output.
Enable: This is a short signal pin that controls the presence of the
12V
DC
on the output connector. 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. Open collector (HI) on this
signal indicates that the input voltage is applied within the specified
input range.
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. Open collector (HI) on this signal
indicates that the output voltage is present.
Temperature OK: A TTL compatible status signal representing
whether an over temperature exists. This signal needs to be pulled
HI externally through a resistor. Open collector (HI) on this signal
indicates that temperatures are normal.
If an over temperature should occur, this signal would pull LO for
approximately 10 seconds prior to shutting down the power supply.
The unit would restart if internal temperatures reduce 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. Open collector (HI) on this signal indicates that no Fault is
present.
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 to detect a missing module.
Interrupt (SMBAlert): A TTL compatible status signal, representing
the SMBusAlert# feature of the PMBus compatible i 2 C protocol in the
power supply. This signal needs to be pulled HI externally through a
resistor. Open collector (HI) on this signal indicates that no Interrupt
has been triggered.
Serial Bus Communications
The I²C interface incorporated within the CAR1212DC modules
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 Bit)
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 I 2 C accessible devices within the power supply.
Address lines (A2, A1, A0): These signal pins allow up to eight (8)
CAR1212DC 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 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.