GE Data Sheet
CAR0812FP series rectifier
Input: 85VAC to 264VAC; Output: 12VDC @ 850W; 3.3VDC or 5 VDC @ 1A
January 7, 2013 ©2016 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 ± 10% of nominal, from
10.8VDC to 13.2VDC. The equation of this signal is:
VOUT = 10.8 + (Vprog * 0.96) where Vprog = 0 to 2.5VDC
Between 2.5 and 3V the output stays at 13.2VDC. If Vprog is >
3V, or left open, the programming signal is ignored and the
unit output is set at the setpoint of 12VDC.
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 12VDC 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 12V
output.
Enable: This is a short signal pin that controls the presence
of the 12Vdc 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.
Fan speed control: The speed of the fan can be increased
above that point that is required for internal cooling. The
speed of the fan cannot be decreased below internal
cooling requirements.
Status signals
Output current monitor (Imon): A voltage level proportional
to the delivered output current is present on this pin. The
signal level is 0.04V 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 for 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
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 requires an external pull-up to 3.3V.
Serial Data (SDA): This line is a bi-directional data line. This
signal requires an external pull-up to 3.3V.