New Dell AC Adapter Charger Inspiron 15, 15-3542,15-3537 Power Adapter 19.5V 3.34A 65W with Pin Size 4.5MM x 3.0MM, please note that Older Version for these models takes the bigger pin size:
AC Adapter Charger Power Cord For Dell Inspiron 15-3542 15-5547 15-3537 15-7537 | eBay