Table 6-2: Input Voltage Characteristics - Kontron CP6930 User Manual

6.1.3.3 Tolerance
The tolerance of the voltage lines is described in the CompactPCI specification (PICMG 2.0 R3.0). The recom-
mended measurement point for the voltage is the CompactPCI connector on the switch.
The following table provides information regarding the required characteristics for each board input volt-
age.
Table 6-2: Input Voltage Characteristics
Voltage Nominal Value
5 V
3.3 V
VI/O (PCI) Voltage +3.3 VDC or +5 VDC
GND
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.
6.1.3.4 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.
All of the input voltages must be functionally coupled to each other
so that if one input voltage fails, the other input voltages must be
regulated proportionately to the failed voltage. For example, if the
+5V begins to decrease, +3.3V must decrease accordingly. This is
required in order to preclude cross currents within the CP6930.
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 sys-
tem 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 seconds before turn-
ing it on again.
Tolerance
+5.0 VDC +5%/-3%
+3.3 VDC +5%/-3%
+5%/-3%
Ground, not directly connected to potential earth (PE)
WARNING
75
Power Considerations
Maxi. Ripple (p-p) Remarks
50 mV Main Voltage
50 mV
50 mV
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CP6930 User Guide