PM5364 pmc-sierra, PM5364 Datasheet - Page 274

• Manufacturer Part Number: PM5364
• Description: Tupp 2488 Assp Telecom Standard
• Manufacturer: pmc-sierra

16.2
16.3
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2011334, Issue 7
2.
Power Sequencing
Due to ESD protection structures in the pads it is necessary to exercise caution when powering a
device up or down. ESD protection devices behave as diodes between power supply pins and
from I/O pins to power supply pins. Under extreme conditions, incorrect power sequencing may
damage these ESD protection devices or trigger latch up.
The recommended power supply sequencing is as follows:
1. There is no requirement on the order that power must be applied to or removed from any of
2. I/Os must only be driven after all the supplies have been powered. Otherwise, the I/Os must
3. The RASIO™ CML receiver inputs do not require current limiting when the receiver is
Power Supply Filtering
1. Use a single plane for both digital and analog grounds.
2. Provide separate analog and digital supplies, but otherwise connect the supply voltages
3. Ferrite beads are not advisable in digital switching circuits because inductive spiking (di/dt
Refer to the TUPP2488 Hardware Design Guidelines (PMC-2020238) for a detailed description
of power supply filtering requirements.
Typical power values are calculated using the formula:
Where i denotes all the various power supplies on the device, VDDNomi is the nominal voltage for
supply i, and IDDTypi is the typical current for supply i (as defined in note 1 above). These values are
suitable for evaluating typical device performance in a system.
the supply pins.
be current limited to 20 mA.
powered down provided the driving voltage is below 1.45V.
together at one point close to the connector where the voltage is brought to the card.
noise) is introduced into the power
provided care is taken to ensure the IR drop in the resistance does not lower the supply
voltage below the recommended operating voltage.
Power = ∑i(VDDNomi x IDDTypi)
rail.
TUPP™ 2488 ASSP Telecom Standard Product Data Sheet
Simple RC filtering is probably the best approach
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