The greenback fetched 118.97 yen in Tokyo afternoon trade, up from 118.86 yen in New York Wednesday afternoon.
The euro bought $1.1370 against $1.1360 while edging up to 135.26 yen from 135.02 yen.
Markets have been rife with speculation over when this year the US central bank will start raising interest rates.
In a second day of testimony to the US Congress, Yellen hewed to a steady path on rates.
She provided no fresh clues on the timing of the rate increase, but again signalled that the central bank was in no rush.
“We did not see anything nefariously dovish in Yellen’s testimony,” National Australia Bank said.
“The only thing that is clear is that (the Fed policy-making) FOMC has given itself more flexibility than before,” the bank said in a note.
“If US data begins to… surprise once more, the market will quickly jump back on to the ‘buy USD’ bandwagon,” it said.
The euro stayed pressured as German Chancellor Angela Merkel said an agreement on a four-month extension of Athens’ bailout was merely a “starting point”.
The dollar was mixed against other Asia-Pacific currencies.
It slipped to 44.09 Philippine pesos from 44.16 pesos on Wednesday, to 12,866.00 Indonesian rupiah from 12,877.00 rupiah and to 61.95 Indian rupees from 62.04 rupees.
The greenback also fell to Sg$1.3535 from Sg$1.3568 and to 32.44 Thai baht from 32.56 baht but rose to Tw$31.44 from Tw$31.43 and to 1,099.98 South Korean won from 1,099.10 won.
The Australian dollar declined to 78.56 US cents from 78.80 cents, while the Chinese yuan fetched 19.00 yen against 18.98 yen. -AFP