Altera Stratix - Designing with 1.5-V Devices; Introduction; Power Sequencing & Hot Socketing

Altera Corporation 14–1
January 2005
14. Designing with
1.5-V Devices
Introduction
The Cyclone
TM
FPGA family provides the best solution for high-volume,
cost-sensitive applications. Stratix
®
and Cyclone devices are fabricated on
a leading-edge 1.5-V, 0.13-µm, all-layer copper SRAM process.
Using a 1.5-V operating voltage provides the following advantages:
■ Lower power consumption compared to 2.5-V or 3.3-V devices.
■ Lower operating temperature.
■ Less need for fans and other temperature-control elements.
Since many existing designs are based on 5.0-V, 3.3-V and 2.5-V power
supplies, a voltage regulator may be required to lower the voltage supply
level to 1.5-V. This document provides guidelines for designing with
Stratix and Cyclone devices in mixed-voltage and single-voltage systems
and provides examples using voltage regulators. This document also
includes information on:
■ Power Sequencing & Hot Socketing
■ Using MultiVolt I/O Pins
■ Voltage Regulators
■ 1.5-V Regulator Application Examples
■ Board Layout
Power
Sequencing &
Hot Socketing
Because 1.5-V Cyclone FPGAs can be used in a mixed-voltage
environment, they have been designed specifically to tolerate any
possible power-up sequence. Therefore, the V
CCIO
and V
CCINT
power
supplies may be powered in any order.
You can drive signals into Cyclone FPGAs before and during power up
without damaging the device. In addition, Cyclone FPGAs do not drive
out during power up since they are tri-stated during power up. Once the
device reaches operating conditions and is configured, Cyclone FPGAs
operate as specified by the user.
f See the Stratix FPGA Family Data Sheet and the Cyclone FPGA Family Data
Sheet for more information.
C51012-1.1