connect AD via php and ssl

I'm trying to connect my php application to authentication with Active Directory of Windows Server 2003, using ssl secure authentication. but it does not connect returns this error

  

PHP Warning: ldap_bind (): Unable to bind to server: Can not contact   LDAP server in /var/www/html/Ldap/teste1.php

// Here is the code I use

AD_server = "ldaps://meuservidor";
$AD_Auth_User = "password";

$protocolVersion = 3;
$ldap = ldap_connect($AD_server);
ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, $protocolVersion) ;

ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0);
ldap_bind($ldap);
if (ldap_errno($ldap)) {
   exit('Nao foi possivel conectar no servidor');
}else{ 
   return true;
}
?>