Altera Corporation
31
EPXA1 Development Board Hardware Reference Manual
A voltage regulator regulates the main supplies for the board. The input
supply is unregulated 12 V (±5%), which is reduced to 3.3 V for the I/O
pins and to 1.8 V for the processor core. Voltage regulator U5 reduces the
input to 5 V and distributes it to a pin on the expansion headers. The
unregulated input is also routed to a pin on the expansion headers.
The maximum current permitted on the expansion headers depends on
the input voltage: for 3.3 V, it is 500 mA, and for 5 V, it is 50 mA. If the
input supply is 12 V, the maximum current per header depends on how
much power is consumed by the rest of the board, but should not exceed
100 mA.
Three function-specific status LEDs indicate the presence of 1.8 V, 3.3 V,
and 5 V to the board, as listed in
through
list the estimated maximum power-supply
requirements for the development board modules.
The typical power-supply requirement for the development
board is 250 mA/500 mA.
Table 18. Power Supply LEDs
Board Reference
Signal
Description
D14
VCC_1V8
Indicates the presence of 1.8 V
D13
VCC_3V3
Indicates the presence of 3.3 V
D12
VCC_5V
Indicates the presence of 5 V
Table 19. 12-V Supply Requirements
Module
Max mA
Expansion headers
100 per header
Table 20. 5-V Supply Requirements
Module
Max mA
CLK_REF
Alternative crystal oscillator—75
Expansion headers
50 per header
Summary of Contents for Excalibur EPXA1
Page 6: ...Notes ...