8. Using MAX II Devices in Multi-Voltage
Systems
MII51009-1.7
Introduction
Technological advancements in deep submicron processes have lowered the supply
voltage levels of semiconductor devices, creating a design environment where devices
on a system board may potentially use many different supply voltages such as 5.0, 3.3,
2.5, 1.8, and 1.5 V, which can ultimately lead to voltage conflicts.
To accommodate interfacing with a variety of devices on system boards, MAX
®
II
devices have MultiVolt I/O interfaces that allow devices in a mixed-voltage design
environment to communicate directly with MAX II devices. The MultiVolt interface
separates the power supply voltage (V
CCINT
) from the output voltage (V
CCIO
), enabling
MAX II devices to interface with other devices using a different voltage level on the
same printed circuit board (PCB).
Additionally, the MAX II device family supports the MultiVolt core feature. For 1.8-V
operation, use the MAX IIG or MAX IIZ devices. The 1.8-V input directly powers the
core of the devices. For 2.5-V or 3.3-V operation, use the MAX II devices. MAX II
devices that support 2.5-V and 3.3-V operation have an internal voltage regulator that
regulates at 1.8 V.
This chapter discusses several features that allow you to implement Altera
®
devices in
multiple-voltage systems without damaging the device or the system, including:
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Hot Socketing—Insert or remove MAX II devices to and from a powered-up
system without affecting the device or system operation
Power-Up Sequence Flexibility—MAX II devices can accommodate any possible
power-up sequence
Power-On Reset—MAX II devices maintain a reset state until voltage is within
operating range
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This chapter contains the following sections:
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ALTERA [ ALTERA CORPORATION ]
