82598EB Datasheet, PDF (540/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - Power Supply Sequencing
Table 7-5. 1.2 V dc Supply Voltage Requirements
Parameter
Description
Rise Time
Time from 10% to 90% mark
Monotonicity
Voltage dip allowed in ramp
Slope
Ramp rate at any given time between 10%
and 90%
Min: 0.8*V(min)/Rise time (max)
Max: 0.8*V(max)/Rise time (min)
Operational Range
Voltage range for normal operating conditions
Ripple
Maximum voltage ripple (peak to peak)
Overshoot
Maximum overshoot allowed
Overshoot Duration
Maximum overshoot allowed duration.
(At that time delta voltage should be lower
than 5mv from steady state voltage)
Suggested Decoupling
Capacitance
Capacitance range
Capacitance ESR
Equivalent series resistance of output
capacitance
Min
0.1
N/A
9.1
1.14
N/A
N/A
0.0
150
5
Max
100
0
10000
1.26
40
100
0.05
175
50
Units
ms
mV
V/s
V dc
mV
mV
ms
μF
M
7.4.2 Power Supply Sequencing
The following relationships between rise times of different power supplies should be maintained to
avoid risk of either latch-up or forward-biased internal diodes:
(T_{3.3 V dc supply} < T_{1.8 V dc supply}) AND (T_{3.3 V dc supply} < T_{1.2 V dc supply})
(1.8 V dc supply < 3.3 V dc supply) AND (1.2 V dc supply < 3.3 V dc supply)
On power-on, after 3.3 V dc reaches 10% of its final value, voltage rails of 1.8 V dc and 1.2 V dc are
allowed 100 ms (T_{3_18}) to reach final operating values. To keep current leakage at a minimum, turn the
rails on almost simultaneously. See Figure 7-1 for the relationship requirements (between 1.8 V dc and
1.2 V dc power supplies).
For the fastest 1.2 V dc ramp: the V_{1.2_1.8} parameter value (maximum voltage difference) should be
less than 0.3 V dc. For the slowest 1.2 V dc ramp: the T_{1.2_1.8} parameter value (maximum time
difference), for below the 0.4 V dc level, should be less than 500 s.
For power-down, turn off all rails at the same time and leave voltage to decay.
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