Reference designs for USB-FPGA Boards
The Eagle files of the reference designs can be used as templates for user defined PCB's.
Comparison
The presented designs mainly differ in the different maximum output currents.
| Experimental Board 1.3 and Power Supply Module 1.1 |
Reference power supply 1 | Reference power supply 2 | ||||||||||||||||||||||||||||||||||||||||||||||
| Usage | All USB-FPGA Modules | USB-FPGA Modules 1.15a, 1.11 and 1.2 | USB-FPGA Modules 1.2 | |||||||||||||||||||||||||||||||||||||||||||||
| Maximum currents / power |
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| Input voltage: | 4.5V to 16V | 4.5V to 16V | 4.5V to 16V | |||||||||||||||||||||||||||||||||||||||||||||
| Number of parts | 32 | 29 | 18 | |||||||||||||||||||||||||||||||||||||||||||||
| Part costs (single unit prices) | approx. 12 USD | 9.90 USD | 7.65 USD |
Experimental Board 1.3 and Power Supply Module 1.1
Please read the comparison section for a list of the key features. Additional details can be found on the product pages of the Experimental Board 1.3 and the Power Supply Module 1.1.The source files can be found in the Eagle files section.
Circuit diagram
Click an on image for a pdf version of the schematics.
Reference Power Supply 1
Please read the comparison section for a list of the key features.- The three voltages are generated independently
Circuit diagram
Click an on image for a pdf version of the schematics.
Recommended PCB Design
Click an on image for a larger version.
Part list
The prices are the prices at Digikey.
| Part | Amount | Value | Package | Digikey PN | Unit price | Price |
| C1 | 1 | 220µF / 25V | 153CLV-0810 | 338-1833-1-ND | 0.410 USD | 0.410 USD |
| C3,C6,C9 | 3 | 10µF / 25V | 1206 | 445-3469-1-ND | 0.330 USD | 0.990 USD |
| C2,C5,C8 | 3 | 22µF | 1206 | 587-2249-1-ND | 0.420 USD | 1.260 USD |
| C5,C7,C10 | 3 | 2.2nF | 0805 | 311-1129-1-ND | 0.046 USD | 0.138 USD |
| CON1 | 1 | DC_SOCKETPJ102 | CP-102AH-ND | 0.530 USD | 0.530 USD | |
| IC1-IC3 | 3 | AOZ1021 | SOIC8 | 785-1155-1-ND | 1.400 USD | 4.200 USD |
| L1-L4 | 3 | 4.7µH | NR60 | 587-2100-1-ND | 0.630 USD | 1.890 USD |
| R1-R3,R5,R9,R10 | 6 | 7.5 kΩ | 0805 | RMCF0805FT7K50CT-ND | 0.040 USD | 0.240 USD |
| R4,R8,R12 | 3 | 2.4 kΩ | 0805 | RMCF0805FT2K40CT-ND | 0.040 USD | 0.120 USD |
| R7 | 1 | 1.2 kΩ | 0805 | RMCF0805FT1K20CT-ND | 0.040 USD | 0.040 USD |
| R6,R11 | 2 | 5.36 kΩ | 0805 | RHM5.36KCRCT-ND | 0.040 USD | 0.080 USD |
| Total: | 29 | Total: | 9,9 USD | |||
Reference Power Supply 2
Please read the comparison section for a list of the key features.- 2.5V and 1.2V are generated from 3.3V
- Instead of MCP1603-2.5V also SC289Y switching regulators can be used (unfortunately poorly available)
- Instead of MCP1603 / SC189 various pin compatible switching regulators can be used (the inductor may need to be adjusted)
Circuit diagram
Click an on image for a pdf version of the schematics.
Recommended PCB Design
Click an on image for a larger version.
Part list
The prices are the prices at Digikey.
| Part | Amount | Value | Package | Digikey PN | Unit price | Price |
| C1 | 1 | 220µF / 25V | 153CLV-0810 | 338-1833-1-ND | 0.410 USD | 0.410 USD |
| C3,C5 | 2 | 10µF / 25V | 1206 | 445-3469-1-ND | 0.330 USD | 0.660 USD |
| C2,C6,C7 | 3 | 22µF | 1206 | 587-2249-1-ND | 0.420 USD | 1.260 USD |
| C4 | 1 | 2.2nF | 0805 | 311-1129-1-ND | 0.046 USD | 0.046 USD |
| CON1 | 1 | DC_SOCKETPJ102 | CP-102AH-ND | 0.530 USD | 0.530 USD | |
| IC1 | 1 | AOZ1021 | SOIC8 | 785-1155-1-ND | 1.400 USD | 1.400 USD |
| IC2 | 1 | MCP1603-2.5V | TSOT23-5 | MCP1603T-250I/OS | 1.190 USD | 1.190 USD |
| IC3 | 1 | SC189C-1.2V | TSOT23-5 | SC189CSKCT-ND | 0.810 USD | 0.810 USD |
| L1 | 1 | 4.7µH | NR60 | 587-2100-1-ND | 0.630 USD | 0.630 USD |
| L2 | 1 | 2.2µH | 1210 | 445-3650-1-ND | 0.330 USD | 0.330 USD |
| L3 | 1 | 4.7µH | 1210 | PCD2336CT-ND | 0.220 USD | 0.220 USD |
| R1-R3 | 3 | 7.5 kΩ | 0805 | RMCF0805FT7K50CT-ND | 0.040 USD | 0.120 USD |
| R4 | 1 | 2.4 kΩ | 0805 | RMCF0805FT2K40CT-ND | 0.040 USD | 0.040 USD |
| Total: | 18 | Total: | 7.65 USD | |||
Eagle files
The zip archive usb-fpga-1_templates.zip contains the schematics, completely routed reference boards and part libraries.A few placing rules for the parts must be considered in order to avoid space conflicts:
- The DC connector and the 220µF/35V capacitor must not be placed below the USB-FPGA Board
If you use the reference designs as a template for you own application please do not forget to connect the I/O voltages VCCO_RIGHT / VCCO_IO and VCCO_TOP.
