PHPで連想配列を日本語エンコードしてCSV出力する ref: http://qiita.com/masarufuruya/items/e5e348ae325740c49795

file0.php

$data = array(
    array('佐藤', '東京都', '29歳'),
    array('田中', '千葉県', '31歳'),
    array('鈴木', '北海道', '54歳')
);

file0.txt

$data = array(
    array('佐藤', '東京都', '29歳'),
    array('田中', '千葉県', '31歳'),
    array('鈴木', '北海道', '54歳')
);

file1.php

$assoc_data = array(
    array('name' => '佐藤', 'address' => '東京都', 'old' => '29歳'),
    array('name' => '田中', 'address' => '千葉県', 'old' => '31歳'),
    array('name' => '鈴木', 'address' => '北海道', 'old' => '54歳')
);

file1.txt

$assoc_data = array(
    array('name' => '佐藤', 'address' => '東京都', 'old' => '29歳'),
    array('name' => '田中', 'address' => '千葉県', 'old' => '31歳'),
    array('name' => '鈴木', 'address' => '北海道', 'old' => '54歳')
);

file2.php

  $csv_header = array(
        'name',
        'address',
        'old',
   );

    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename=data.csv');

    $stream = fopen('php://output', 'w');
    fputcsv($stream, $csv_header);

    foreach($assoc_data as $key => $assoc_row){
        $numeric_row = array();
        foreach ($csv_header as $header_name) {
            mb_convert_variables('SJIS-win', 'UTF-8', $assoc_row[$header_name]);
            $numeric_row[] = $assoc_row[$header_name];
        }
        fputcsv($stream, $numeric_row);
    }

file2.txt

  $csv_header = array(
        'name',
        'address',
        'old',
   );

    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename=data.csv');

    $stream = fopen('php://output', 'w');
    fputcsv($stream, $csv_header);

    foreach($assoc_data as $key => $assoc_row){
        $numeric_row = array();
        foreach ($csv_header as $header_name) {
            mb_convert_variables('SJIS-win', 'UTF-8', $assoc_row[$header_name]);
            $numeric_row[] = $assoc_row[$header_name];
        }
        fputcsv($stream, $numeric_row);
    }

file3.txt

mb_convert_encording