IBM3229P2035
IBM Packet Routing Switch Serial Interface Converter
Advance
8. Electrical Specifications
Table 32: Absolute Maximum Ratings
Parameter
VDD
Description
Min
-0.5
-0.5
-0.5
Typ
2.5
Max
2.7
Units
Supply voltage VDD
Input voltage
V
V
V
VIN
VDD+0.6
VDD+0.6
VOUT
Output voltage
Thermal impedance junction to ambient package
Airflow=0
14.7
13.3
°C/W
°C/W
°C/W
Thermal impedance junction to ambient package
Airflow=100FPM
Thermal impedance junction to ambient package
Airflow=200FPM
11.9
1.9
Thermal impedance junction to case package
Storage temperature
°C/W
°C
TS
TA
-65
0
150
125
Operating junction temperature range
Electrostatic discharge
°C
-3.000
6,000
3,000
V
Note: Permanent device damage may occur if the above absolute maximum ratings are exceeded. Functional operation should be
restricted to the conditions as detailed in the operational section of this data sheet. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
8.1 Power Sequencing
In order to prevent latchup (and destruction) of the chip, the power supplies must be sequenced up and down
in a manner that any supply is greater than or equal to the voltage of another supply of lesser value both
during "turn on" and "turn off" (including a quick toff - ton sequence).
For example, 3.3 V >/= 2.5 >/= 1.5 V during power up and power down. Actually up to 400 mV of negative
voltage can be tolerated during the sequence between any two supplies. There is no time delay requirement,
only a negative voltage restriction. Ideally, all supplies would rise together until they reach their operating
level and all would fall together until they reach zero.
If one could design a 400 mV (max) diode and place it between 3.3 V (cathode) and 2.5 V (anode), and
another between 2.5 V (cathode) and 1.5 V (anode), that would ensure that the 400mV diodes internal to the
chip did not get forward biased more than the 400 mV, which would keep the chip out of latchup conditions.
Also, the 3.3 V supply should not exceed the 2.5 V supply by more than 2.7 V during power up/down, and
1.3V in constant use.
Electrical Specifications
Page 126 of 154
prssi.02.fm
March 1, 2001
IBM [ IBM ]
