I've never heard of an off-the-shelf chip that performs that function. The 74hc147 decodes decimal into BCD, but that's about all I know of. You could program a rom (EPROM, EEPROM , whatever) to do it. Use the seven-segment data as the address input data to the rom and the rom's data bus as the BCD output. This would waste a lot of rom space, as only a total of ten addresses (those corresponding to numbers 0-9) would be used. Or, you could just program a PIC to do it.
JB