Can't find compatible drivers for PHP

I’m running Windows 7 Pro, SQL Server 2012, and installed xampp for PHP version 5.6.3. Thread safety is enabled. I cannot find Microsoft SQL Server drivers that are compatible with this version. I’m using the following from SQLSRV31.EXE in my PHP extensions:

extension=php_pdo_sqlsrv_55_ts.dll

extension=php_sqlsrv_55_ts.dll

but I’ve tried all the available drivers and get variations of the same message when trying to run:

"PHP Startup: sqlsrv: Unable to initialize module Module compiled with module API=20100525 PHP  compiled with module API=20131226. These options need to match."

I can’t find any MS drivers for 5.6. Is there a solution? Do I need to  install the earlier versions of xampp?