AN 490: Altera MAX Series as Voltage Level Shifters

ID 683233
Date 9/22/2014

1.1. Multi-Voltage Systems

Devices on one circuit board can potentially use many different supply voltages, such as 5V, 3.3V, 2.5V, 1.8V, 1.5V, and 1.2V. Therefore, the buses connected to a system can have different voltage standards that can lead to voltage-level conflicts. MAX II devices are designed to interface directly with 1.5-V, 1.8-V, 2.5-V, and 3.3-V signals and can be used to eliminate these conflicts. MAX V and MAX 10 supports direct interface with 1.2-V, 1.5-V, 1.8-V, 2.5-V, and 3.3-V signals.

The supported devices can interface with other devices using different voltage levels because the core power supply voltage (VCCINT or VCC_ONE for MAX 10) is separate from the device output voltage (VCCIO). A few applications for voltage level shifting are:

  • Interfacing microprocessors with peripheral devices, timers, and transceivers that are operating at different I/O standards and levels
  • Driving more than one set of GPIO pins having different I/O standards