The dollar rose to 103.91 yen in Tokyo morning trade from 103.
83 in New York late Monday.
The euro slipped to 1.5515 dollars from 1.5542 and to 161.19 yen from 161.38.
"The market has been range-bound...
as worries over the financial system have receded," Credit Suisse strategist Satoru Ogasawara said.
"Now that excessive pessimism over the US economy and dollar have diminished, (investors) are now focused on economic fundamentals," he said.
Market players were waiting to hear whether Bernanke would "talk about downside risks or suggest the worst (of the credit crisis) is over," he added.
The top US central banker was due to speak Tuesday at a financial markets conference organised by the Federal Reserve Bank of Atlanta.
Traders were also bracing for a slew of US economic indicators due this week, including retail sales Tuesday, consumer price inflation on Wednesday and housing starts on Friday.
A rebound in shares on Wall Street "discouraged short-term speculato