Kontron CP308, Руководство пользователя

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CP308 Power Considerations
ID 1027-4487, Rev. 3.0 Page 5 - 5
P R E L I M I N A R Y
5.1.3.3 Tolerance
The tolerance of the voltage lines is described in the CPCI specification (PICMG 2.0 R3.0).The
recommended measurement point for the voltage is the CPCI connector on the CPU board.
The following table provides information regarding the required characteristics for each board
input voltage.
The output voltage overshoot generated during the application (load changes) or during the
removal of the input voltage must be less than 5% of the nominal value. No voltage of reverse
polarity may be present on any output during turn-on or turn-off.
5.1.3.4 Regulation
The power supply shall be unconditionally stable under line, load, unload and transient load
conditions including capacitive loads. The operation of the power supply must be consistent
even without the minimum load on all output lines.
Table 5-3: Input Voltage Characteristics
VOLTAGE NOMINAL VALUE TOLERANCE MAX. RIPPLE (p-p) REMARKS
+5 V +5.0 VDC +5%/-3% 50 mV Main voltage
+3.3 V +3.3 VDC +5%/-3% 50 mV Main voltage
+12 V +12 VDC +5%/-5% 240 mV Not required
-12 V -12 VDC +5%/-5% 240 mV Not required
V I/O (PCI)
signalling voltage
+3.3 VDC or +5 VDC +5%/-3% 50 mV --
+5 V STDBY +5.0 VDC +5%/-3% 50 mV Optional voltage
over J2 con.
GND Ground, not directly connected to potential earth (PE)
Warning!
All of the input voltages must be functionally coupled to each other so that if
one input voltage fails, all other input voltages must be regulated proportion-
ately to the failed voltage. For example, if the +5V begins to decrease, all other
input voltages must decrease accordingly. This is required in order to preclude
cross currents within the CP308.
Failure to comply with above may result in damage to the board or improper
system operation.
Note ...
If the main power input is switched off, the supply voltages will not go to 0V
instantly. It will take a couple of seconds until the capacitors are discharged. If
the voltage rises again before it has gone below a certain level, the circuits
may enter a latch-up state where even a hard RESET will not help any more.
The system must be switched off for at least 3 seconds before it may be
switched on again. If problems still occur, turn off the main power for 30 sec-
onds before turning it on again.