hallovipin
Member level 1
Hi ,
I am designing my first FPGA board and have few doubts regarding FPGA power supply selection. Please help in clarifying the following:
1.
Is it proper to use switched mode regulators directly as FPGA supplies without using LDOs. I used National Semiconductor's WEBENCH tool (**broken link removed**) and they are suggesting three different switched mode regulators for three supplies of FPGA (1.2V, 2.5V and 3.3V). All these regulators are down converting the 12 volt input supply to 1.2V, 2.5V and 3.3V. Is it proper to have 12V to 1.2V conversion without having an intermediate converter?
Please have a look on the following power supply solutions from TI. they are SMD power module by TI. Do you think they can be used in the design...
**broken link removed**
Plug-in Power Module - Non-Isolated POL - PTH08T230W - TI.com
2.
I am thoroughly confused in choosing the voltage level for VCCAUX supply. We have all the I/Os with 3.3Volts. What do you think VCCAUX should be; 3.3V or 2.5V? As per the datasheet both the levels are acceptable.
3.
If we are interfacing an SPI based device (in our case RTC) to FPGA.. is it necessary to use dedicated FPGA I/Os (MOSI, MISO etc) or any of the I/Os.
Thanx a lot.
- Vipin
I am designing my first FPGA board and have few doubts regarding FPGA power supply selection. Please help in clarifying the following:
1.
Is it proper to use switched mode regulators directly as FPGA supplies without using LDOs. I used National Semiconductor's WEBENCH tool (**broken link removed**) and they are suggesting three different switched mode regulators for three supplies of FPGA (1.2V, 2.5V and 3.3V). All these regulators are down converting the 12 volt input supply to 1.2V, 2.5V and 3.3V. Is it proper to have 12V to 1.2V conversion without having an intermediate converter?
Please have a look on the following power supply solutions from TI. they are SMD power module by TI. Do you think they can be used in the design...
**broken link removed**
Plug-in Power Module - Non-Isolated POL - PTH08T230W - TI.com
2.
I am thoroughly confused in choosing the voltage level for VCCAUX supply. We have all the I/Os with 3.3Volts. What do you think VCCAUX should be; 3.3V or 2.5V? As per the datasheet both the levels are acceptable.
3.
If we are interfacing an SPI based device (in our case RTC) to FPGA.. is it necessary to use dedicated FPGA I/Os (MOSI, MISO etc) or any of the I/Os.
Thanx a lot.
- Vipin