Taiwan Semiconductor Corporation P4KE51CA

Overview

P4KE51CA from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-204AL (DO-41) package, designed for high-energy ESD and surge protection in power rails and signal lines. It features a 51 V nominal breakdown voltage (VBR min/max = 45.9–56.1 V at 1 mA), 400 W peak pulse power rating (10/1000 µs), and clamps transients to ≤73.5 V at 5.7 A peak pulse current.

For engineers reviewing the P4KE51CA datasheet, P4KE51CA pinout, P4KE51CA application, or P4KE51CA equivalent, key selection criteria include bidirectional clamping capability, low leakage (<1 µA at 41.3 V), fast response time (<5 ns), AEC-Q101 qualification option, and compatibility with automotive and industrial board-level surge immunity standards including IEC 61000-4-2/4-4/4-5.

Technical Context

The P4KE51CA operates as a voltage-clamped shunt protector: under normal conditions it presents high impedance (>1 MΩ at 41.3 V), but avalanches rapidly when transient voltage exceeds its breakdown threshold, diverting surge current away from downstream circuitry. Its bidirectional symmetry enables use on AC lines or ungrounded differential signals without polarity concerns.

It complies with ANSI/IEEE C62.35 for transient suppression, supports 10/1000 µs waveform testing, and maintains stable VBR over temperature with a +0.102 %/°C coefficient. Junction temperature range spans –55 °C to +175 °C, enabling deployment in under-hood automotive or high-ambient industrial environments.

Key Specifications

Pinout & Package

DO-204AL (DO-41) axial-leaded package with cathode band marking for unidirectional variants; P4KE51CA is bidirectional and has no polarity marking-both terminals are functionally identical.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMAJ51CA and 1.5KE51CA, the P4KE51CA offers optimal balance of axial through-hole compatibility, precise 51 V clamping, and AEC-Q101 qualification path-making it ideal for cost-sensitive automotive and industrial control boards where DO-41 mounting and proven reliability are prioritized.

Availability

P4KE51CA is available at Aetrix Electronics and suitable for automotive lighting systems, industrial PLC analog inputs, RS-485 communication lines, and AC-DC power supply input stages requiring stable component supply and long-term lifecycle support.

Supply support for P4KE51CA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101 qualification capabilities.

The P4KE series targets board-level transient protection in automotive, industrial, and consumer applications-designed for robustness, consistency, and compliance with international surge immunity standards.

FAQ

What is the clamping voltage of P4KE51CA at its rated peak pulse current?

The P4KE51CA clamps to a maximum of 73.5 V at its specified peak pulse current of 5.7 A under the 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and represents the upper limit of voltage seen by protected circuitry during a full-rated surge event. The P4KE51CA maintains this clamping performance across its operating temperature range and is validated for repeated surge events when thermally managed per datasheet derating curves.

Is P4KE51CA unidirectional or bidirectional, and how does that affect PCB layout?

P4KE51CA is a bidirectional TVS diode, meaning both terminals are electrically symmetrical and function identically regardless of voltage polarity. Unlike unidirectional variants (e.g., P4KE51A), it has no cathode band marking and imposes no polarity constraint on PCB layout-ideal for AC-coupled lines like RS-485 or transformer-isolated power rails. This eliminates orientation errors during assembly and simplifies design reuse across differential and floating interfaces.

Does P4KE51CA meet AEC-Q101 qualification, and what does that mean for automotive use?

The base P4KE51CA is not AEC-Q101 qualified; however, the P4KE51CAH variant (with "H" suffix) is fully AEC-Q101 qualified per stress test conditions including HTGB, HTRB, TCT, and mechanical shock. For automotive applications such as body control modules or lighting drivers, specifying P4KE51CAH ensures compliance with automotive reliability requirements-including operation from –40 °C to +125 °C ambient and lifetime validation under thermal cycling and humidity bias.

How does the 400 W rating of P4KE51CA relate to real-world surge standards like IEC 61000-4-5?

The 400 W rating of P4KE51CA corresponds to its ability to handle a 10/1000 µs surge waveform at 5.7 A peak current, which aligns with IEC 61000-4-5 Level 3 (1 kV line-to-line, 2 kV line-to-earth) when applied to typical source impedances. In practice, the P4KE51CA protects downstream circuitry by limiting transient voltage to ≤73.5 V-well below the breakdown thresholds of most 3.3 V/5 V/12 V ICs-making it suitable for secondary-side protection in industrial and automotive power domains.

What is the maximum reverse leakage current of P4KE51CA, and why does it matter for low-power circuits?

The P4KE51CA exhibits a maximum reverse leakage current of 1 µA at its working stand-off voltage of 41.3 V. This ultra-low leakage prevents measurable loading on high-impedance nodes-such as sensor bias networks, battery-monitoring dividers, or microcontroller wake-up inputs-where even nanoamp-level currents could cause measurement error or premature wake-up. The P4KE51CA maintains this specification across its full –55 °C to +175 °C junction temperature range.