SMA4F ESD Suppressor (TVS) Diodes Taiwan Semiconductor SMA4F ESD Suppressor (TVS) Diodes protect electronics from voltage spikes induced on connected wires. Electro-static discharge (ESD) suppressors work with transient-voltage-suppression (TVS) diodes to protect components with up to 400W surge capability. Taiwan Semiconductor SMA4F TVS Diodes are ideal for switching mode power supplies, lighting applications, battery management systems, brushless DC electric motors, and automotive applications.