while($row = mysqli_fetch_array($query))
{
    echo "<tr class = 'raw' id = 'data'>";
    echo "  <td><button onclick = 'gettahun(".$row['kdTahun'].")' data-dismiss='modal'>#</button></td>";
    echo "  <td class = 'kdTAHUN'>".$row['kdTahun']."</td>";
    echo "  <td class = 'TAHUN'>".$row['tahun']."</td>";
    echo "</tr>";
}

function getfakultas(pilih)
{
    $.ajax({
        type: "GET",
        url: "routes/getfakulas.php",
        data: {"kdFakultas":pilih},
        success: function(hasil)
        {
            var result = $.parseJSON(hasil);
            $("#kdFakultas").val(result.KDFAKULTAS);
            $("#Fakultas").val(result.FAKULTAS);
            $('#kdFakultas').attr('readonly', true);
        },
        error:function (xhr, ajaxOptions, thrownError){
           if(xhr.status==404) {
               alert(thrownError);
          }
       }
    });
}

<?php
session_start();
$host = "localhost";
$user = "root";
$pass = "";
$name = "buku_tahunan";

$koneksi = mysqli_connect($host,$user,$pass,$name);

if(mysqli_connect_errno())
{
    die("koneksi DB Gagal".mysqli_connect_error());
}
$kdfakultas = $_GET["kdFakultas"];

$sql="SELECT * FROM `fakultas` WHERE kdFakultas = '$kdfakultas'";

$query = mysqli_query($koneksi,$sql);

while($row = mysqli_fetch_array($query))
{
    $output =  array('KDFAKULTAS'=>$row['kdFakultas'],
             'FAKULTAS'=>$row['nmFakultas']);
    echo json_encode($output);
}
 ?>