The string "A" isn't a number so none of the number or character expecting formats will do what you're apparently expecting (when converted to a number the numeric value is zero). Pass a number if you want to format a number (chr and/or ord will probably be of interest).

$ perl -E '$x = ord(q{A});printf( join( qq{\t}, qw( %c %x %d ) ) . qq{
+\n}, ($x)x3 )'
A       41      65
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