Resolvido da seguinte forma:

       var url = WCMAPI.getServerURL();

        var oauth =
            OAuth({
                consumer: {
                    key: '***',
                    secret: '***'
                },
                signature_method: 'HMAC-SHA1',
                hash_function: function(base_string, key) {
                    return CryptoJS.HmacSHA1(base_string, key).toString(CryptoJS.enc.Base64);
                },
                nonce_length: 6               
        });

        var token = {
            key: '***',
            secret: '***'
        };       

        var request_data = {
                url: url+'/api/public/2.0/documents/getDownloadURL/' + documentId, 
                method: 'GET',            
                data: {}
        };

        $.ajax({
            type: request_data.method,
            headers : oauth.toHeader(oauth.authorize(request_data, token)),
            cache: false,
            dataType: 'json',
            contentType : 'application/json',
            url: request_data.url,
            success: function (data, status, xhr) {
                window.open(data.content, '_blank');                
            },
            error: function(xhr, status, error) {
                    FLUIGC.toast({
                        message: 'Falha ao carregar documento',
                        type: 'danger',
                        timeout: 'slow'
                    });
            }
        });