Complete USB2LPT 1.7 photo

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

To USB2LPT — Overview

USB2LPT – Cloning instructions for Release 1.7

Eagle3d picture
New: The do-it-yourself process is available at YouTube! (Three clips, running time ca. 30 minutes, some German comments, English subtitling)
  1. Solder paste applying, SMD population
  2. SMD population (cont.), Reflow process, SubD receptacle
  3. USB receptacle, Quartz crystal, LEDs, Housing shell, Final check

Electronic Components

Almost identical to Release 1.3. Except voltage regulator:

insteadnowMarkingGND currentoutput currentoptionsattention
LD1117S33TPS79733DCKATF1,3 µA 50 mA (190 mA typ.)PowerGood outputPopulate C4
3,2 µA 50 mA (125 mA min.)
TPS71433DCKCVH 80 mA (100 mA min.)
TPS77033DBVPCXI17 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.
TPS78833DBVPGTI150 mA (350 mA typ.)
TPS76933DBVPCNI18 µA100 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:-)

Inside DeviceInside Device
Populated PCB. The capacitor C4 is exceptionally populated with an SMD tantalum capacitor


Solder Jumper

Same as for Revision 1.4.