Keywords: USB, LPT, parallel, parallel port, printer port, converter, adaptor

Converter from USB to parallel port (25 pin SubD receptacle) with hardware virtualization at input/output instruction level
Supports all parallel port modes named SPP, EPP and ECP, 16 Byte FIFO depth
USB High Speed (480 Mbit/s signaling; 8 kByte/s at input/output instructions)
Multifunction device with extra USB to parallel printer support in accordance to USB printer class specification
Full open-source, even for schematics and PCBs

USB2LPT – Cloning instructions for Release 1.7

New: The do-it-yourself process is available at YouTube! (Three clips, running time ca. 30 minutes, some German comments, English subtitling)

Solder paste applying, SMD population
SMD population (cont.), Reflow process, SubD receptacle
USB receptacle, Quartz crystal, LEDs, Housing shell, Final check

Electronic Components

Almost identical to Release 1.3. Except voltage regulator:

instead	now	Marking	GND current	output current	options	attention
LD1117S33	TPS79733DCK	ATF	1,3 µA	50 mA (190 mA typ.)	PowerGood output	Populate C4
	TPS71533DCK TPS71533QDCK	AQI ANW	3,2 µA	50 mA (125 mA min.)	–
	TPS71433DCK	CVH	3,2 µA	80 mA (100 mA min.)	–
	TPS77033DBV	PCXI	17 µA	50 mA (340 mA typ.)	inverse enable input (not used here)	Do not populate C4! Instead, populate electrolytic or tantalum capacitor 10 µF into two holes beneath C4. This is because ESR must have a minimum for stable operation.
	TPS78833DBV	PGTI	17 µA	150 mA (350 mA typ.)
	TPS76933DBV	PCNI	18 µA	100 mA (350 mA typ.)

Values in parentheses are for internal current limitation

The overall current consumption of this device in USB idle state should now be about 500 µA, as required by USB specification.
(The EZUSB-FX2 chip itself contributes 500 µA:-)

Software

Circuit Diagram and PCB Silkscreen, Source for PCB software Eagle
Firmware same as Revision 1.3

Solder Jumper

Same as for Revision 1.4.