Fail to connect php mysql with pdo

Question

I have a problem to connect PHP with MySQL this is my connexion file:

    <?php
    try {
        $pdo = new PDO('mysql:host=localhost;dbname=ecom;charset=utf8', 'root', '');
    }
    catch (PDOException $e) {
        die($e->getMessage());
     }

    ?>

it show's me this error:

could not find driver

I'm using xampp btw as a server 3.2.4 last version