SE7221BK1-E Technical Product Specification
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10.2 Power Supply Specifications
This section provides power supply design guidelines for the baseboard, including voltage and
current specifications, and power supply on/off sequencing characteristics.
Table 79. The Board Power Supply Voltage Specification
PARAMETER TOLERANCE MIN NOM MAX UNITS
+ 3.3V - 5% / +5% +3.14 +3.30 +3.46 Vrms
+ 5V - 5% / +5% +4.75 +5.00 +5.25 Vrms
+ 12V - 5% / +5% +11.40 +12.00 +12.60 Vrms
- 12V - 10% / +10% -11.40 -12.00 -13.08 Vrms
+ 5VSB - 5% / +5% +4.75 +5.00 +5.25 Vrms

10.2.1 Power Timing Requirements

These are the timing requirements for the power supply operation. The output voltages must
rise from 10% to within regulation limits (Tvout_rise) within 5 to 70ms, except for 5VSB - it is
allowed to rise from 1.0 to 70ms. The +3.3V, +5V and +12V output voltages should start to rise
approximately at the same time. All outputs must rise monotonically. The +5V output needs
to be greater than the +3.3V output during any point of the voltage rise. The +5V output must
never be greater than the +3.3V output by more than 2.25V. Each output voltage shall reach
regulation within 50ms (Tvout_on) of each other during turn on of the power supply. Each
output voltage shall fall out of regulation within 400msec (Tvout_off) of each other during turn
off. Refer to the table below for the timing requirements for the power supply being turned on
and off via the AC input, with PSON held low and the PSON signal, with the AC input applied.
Table 80. Output Voltage Timing
Item Description MIN MAX UNITS
Tvout_rise Output voltage rise time from each main output. 5.0 * 70 * msec
Tvout_on All main outputs must be within regulation of each
other within this time. 50 msec
T vout_off All main outputs must leave regulation within this
time. 400 msec
• The 5VSB output voltage rise time shall be from 1.0ms to 25.0ms