Some time back I purchased all ebay types of USB/TTL dongles to test.
I've got 3 blue PL2303TA - they all work under Win7. When opened they show TA chip markings. Sometimes one of them disconnects after few hours, not sure it is because it is a fake.
The FT232 based dongles work well - de facto standard, but expensive.
The other types (Silabs 2102, CH340 based) - they work at lower speeds well, I saw issues at speeds >115k2 (especially those crystal-less).
Also mind the types vary on the baud speed steps they offer.
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