GE Industrial Solutions PIM300X Series - Manual (Page 13)

Data Sheet
November 29, 2010
PIM300X Series; ATCA Board Power Input Modules
-38 to -75Vdc; 300W Input
LINEAGE POWER 13
The -48V_OUT bus may require a fuse
depending on the power and fusing
requirements of the DC/DC converter.
Input filtering of the DC/DC converter is
provided by C_FLTR close to the input pins
of the DC/DC converter(s); additional high
frequency decoupling ceramic capacitors
(0.01 to 0.1
μF are recommended for
improved EMI performance.
The maximum C_FLTR capacitance across
all the downstream DC/DC converters
should not exceed 330
μF. The
recommended capacitor voltage rating
should be >/= 100Vdc.
The minimum C_FLTR capacitance (200 μF)
recommendation is based on meeting the
EMI requirements. Based on end systems
test, the capacitance may be lowered if real
estate is an issue. As a minimum, 50
μF to
100 μF is strongly recommended to stabilize
the line impedance for proper startup of the
DC/DC converter. Refer to the DC/DC
converter’s data sheet for the recommended
capacitor.
(2) Holdup / Bulk Capacitor Output (72V_CAP)
This output provides the high voltage (nominal 72Vdc)
to charge the C_BULK capacitor(s) to allow the ATCA
board to meet the 5ms, 0Volts transient requirements.
The 72V_CAP connects to the +ve terminals
of the C_HLDP capacitors while the
–ve
terminals of the C_HLDP connects to the -
48V_OUT bus.
Since the 72V_CAP output is regulated to
72Vdc (+3%/-5%) and the capacitors are off
line during normal operation, the capacitors
may be selected with voltage rating of >/=
80V to minimize the real estate on the board.
The C_HLDP capacitance is dependent on
the system power and the holdup time
requirements based on the following formula
9 . 1 / }] 7 . 1 ) ( { ) ( [ ) ( _ ms T W P F HLDP C
holdup out
Bleed Resistor (R_Bleed) : The PICMG 3.0
specifications requires a discharge
mechanism (e.g. bleed resistor) to discharge
the holdup/bulk capacitance to less than -
60Vdc and less than 20 joules within one
second of disconnection from the backplane.
This requirement is fulfilled by installing
R_Bleed resistor that is selected based on
the C_HLDP selected in the previous step.
The formula for selecting the resistor is :
) ( _ / 485 . 5 ) ( _ F HLDP C Bleed R
For 300W and 9.3 ms holdup requirements,
this results in a 2.9 Kohm resistor with 1W
rating.
Worst case power dissipation of R_Bleed
(=2.9Kohms) @ -36V is 0.45W.
The R_Bleed is connected across the
72V_CAP and VRTN_OUT pins of the
PIM300X.
(3) Management Power
(MGMT_PWR)
The MGMT_PWR output is an isolated secondary
voltage (3.3V for PIM300F or 5.0V for PIM300A)
referenced to LOGIC_GND that provides
8W(maximum) power to the IPM Controller for the
ATCA board or to the power up system controller for
other applications.
Per PICMG 3.0 Specs, the ATCA board
shall not consume more than 10W of input
power; this includes the standby power of
PIM300X (typically 1.7W) as well as all the
on board DC/DC power converters. It is the
responsibility of the board designer to insure
that this requirement is met prior to power-up
rights have been negotiated with the Shelf
Manager.
The management power is available even
when the input voltage is down to
–36Vdc.
No additional output capacitors are required,
but a 22
μF tantalum/ceramic and a 0.01 to
0.1μF ceramic capacitors are highly
recommended to contain the switching ripple
and noise.
Higher output capacitance may be required
in case of large input line or output load
transient conditions.
(4) -48V Feed Loss or Open Fuse Alarm
(-48V_ALARM)
The -48V_ALARM output is an opto-isolated signal
internally referenced to the LOGIC_GND. The signal
is an open collector output that requires an external
pull up resistor. A 3.3K pull up resistor to 3.3V,
MGMT_PWR (for PIM300F) should suffice. During
normal operation, the signal is LO (opto conducting).
During fault condition, the opto shall stop conducting
and the alarm signal shall assume a HI state.
Safety Considerations
For the system safety agency approval the power
module must be installed in compliance with the
spacing and separation requirements of the end-use
safety agency standards, i.e., UL 60950-1, CSA
C22.2 No. 60950-1-03, and VDE 0850:2001-12
(EN60950-1) Licensed.