FPDI shows blank pdf

Good I want to generate several sheets of pdf through a url that I send but it does not show me anything, if I remove and paste in an url the address without the array if it shows it well, but what I want is that in a pdf full show me information and apart in another pdf sheet I show what the other url contains, but I leave blank the sheet does not mark any error or anything

Code

$persona = $this->modelo->persona_pdf($id); 

ob_start();

$pdf = new pdi();

foreach ($persona as $per) {
$pdf->AddPage();
$pagecount = $pdf->setSourceFile("paso mi url'$per->nombre'/'$per->apellido'");
            }

$pdf->Output('Personas', "I");