1 Introduction

First let’s define some terms. In a car door, the latch provides safety by holding the door closed, while the lock provides security by preventing the latch from being released. The latch is a mechanical device that engages with a striker on the door frame to keep the door shut. The lock, often integrated with the latch mechanism, uses a key or electronic system to prevent the latch from disengaging, thus securing the door.

Traditional automotive doors rely on complex mechanical linkages to engage and disengage a pawl with a striker, enabling door opening and closure. Electric locks have been common for years, but these have typically simply added a small electric motor to drive the existing mechanical linkages.

Figure 1-1 Typical Mechanically Complex Door Latch and Lock Example

E-latch systems, in contrast, tend to replace the mechanical linkages with electronics and electrical wiring. These "E-latches" offer new functionalities and design possibilities that surpass the capabilities of mechanical predecessors. With the increasing integration of electronics and advanced features in vehicles, the transition to electronically controlled latches is gaining traction.

With the electrification of the latches and locks, these functions become dependent on the electric power typically supplied by the car battery. For safety reasons, a backup power supply is often part of the E-latch system.