The Fed hosts its annual retreat in Jackson Hole, Wyoming this week, with Bernanke slated to make a speech on Friday. It was at this same event last year that Bernanke hinted at the Fed's second round of bond purchases, known as quantitative easing.

A third round of quantitative easing would be negative for the dollar as it is tantamount to printing money and dilutes the dollar's value.

The dollar was last up 0.9 percent at 77.640 yen after rising as high as 77.673 yen on electronic trading platform EBS, its highest level since Aug. 5. A record low of 75.941 was set last week.

Copyright Reuters, 2011