Taiwan Semiconductor Corporation P4KE91H

Overview

P4KE91H from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power rails and signal lines. It features a 91 V nominal breakdown voltage (VBR min/max: 81.9–100 V at 1 mA), 73.7 V working stand-off voltage (VWM), 131 V maximum clamping voltage (VC) at 3.2 A peak pulse current, and 400 W peak pulse power rating per 10/1000 μs waveform - deployed in automotive engine control units to safeguard CAN transceivers against load dump and ISO 7637-2 pulses.

For engineers reviewing the P4KE91H datasheet, P4KE91H pinout, P4KE91H application, or P4KE91H equivalent, key selection criteria include clamping voltage margin relative to protected IC's absolute maximum rating, leakage current (<1 μA at 73.7 V), AEC-Q101 qualification status, DO-41 package thermal performance under sustained surge stress, and unidirectional polarity marking alignment with system ground-referenced topology.

Technical Context

The P4KE91H operates as a silicon avalanche diode with fast response time (<1.0 ps from 0 V to VBR), low dynamic impedance, and tightly controlled breakdown voltage tolerance (±5% for 'A' grade; P4KE91H is standard grade, ±10%). Its junction temperature range spans –55 °C to +175 °C, supporting under-hood automotive environments without derating up to 125 °C ambient.

It complies with ANSI/IEEE C62.35 for transient suppression testing, delivers 3.2 A peak pulse current (IPPM) at 131 V clamping, and exhibits a 0.106 %/°C VBR temperature coefficient - enabling predictable overvoltage threshold shift across operating temperature extremes.

Key Specifications

Pinout & Package

DO-204AL (DO-41) package: axial leaded, molded epoxy case with cathode band marking for unidirectional polarity. Leads are pure tin plated, compliant with JESD 201 Class 2 whisker resistance and UL 94V-0 flammability rating. Weight ≈ 0.300 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ90A and P6KE91A, the P4KE91H offers optimal balance of proven through-hole mechanical robustness, AEC-Q101 compliance, and cost-effective surge immunity for automotive and industrial power rails - especially where vibration resistance and manual repairability are prioritized over footprint minimization.

Availability

P4KE91H is available at Aetrix Electronics and suitable for automotive powertrain modules, industrial PLC input stages, LED driver power supplies, and telecom line interface cards requiring stable component supply with full AEC-Q101 traceability and long-term lifecycle support.

Supply support for P4KE91H 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in power management, protection, and signal conditioning devices since 1979.

The P4KE91H belongs to TSC's AEC-Q101-qualified P4KE series of axial-leaded TVS diodes, engineered specifically for harsh-environment transient suppression in automotive, industrial, and infrastructure applications where reliability under thermal and electrical stress is non-negotiable.

FAQ

What is the clamping voltage of the P4KE91H and how does it protect downstream components?

The P4KE91H clamps at 131 V when subjected to its rated 3.2 A peak pulse current (10/1000 μs waveform). This means that during a surge event, the voltage across the P4KE91H will not exceed 131 V, diverting excess current to ground and holding the protected line within a safe window. For example, if a CAN transceiver has an absolute maximum rating of 135 V, the P4KE91H provides a 4 V safety margin - critical for preventing permanent damage during ISO 7637-2 load dump events. The P4KE91H achieves this via controlled avalanche breakdown with low dynamic impedance.

Is the P4KE91H suitable for bidirectional signal line protection such as RS-485 or USB?

No - the P4KE91H is a unidirectional TVS diode, marked with a cathode band and specified only for DC rail or single-polarity signal protection. It conducts only when the cathode is positive relative to the anode. For bidirectional lines like RS-485 differential pairs or USB data lines, a bidirectional variant (e.g., P4KE91CA) or symmetric dual-diode configuration is required. Using the P4KE91H on bidirectional signals would result in forward conduction and potential short-circuit behavior during negative transients.

How does the AEC-Q101 qualification of the P4KE91H impact its use in automotive applications?

AEC-Q101 qualification confirms that the P4KE91H has passed accelerated stress tests including high-temperature reverse bias (HTRB), temperature cycling, and ESD (HBM ≥ 8 kV), validating its suitability for automotive powertrain, chassis, and body electronics. This certification assures design-in confidence for under-hood environments where junction temperatures reach 175 °C and reliability over 15+ years is mandatory. The P4KE91H's qualification eliminates the need for additional qualification testing by Tier 1 suppliers - accelerating time-to-market for automotive ECUs.

What is the maximum steady-state power dissipation of the P4KE91H and how should thermal design be approached?

The P4KE91H has a steady-state power dissipation (PD) rating of 1 W at lead temperature TL = 75 °C, measured with 9.5 mm lead lengths mounted on 5 × 5 mm copper pads. In practice, it is not intended for continuous power dissipation - its role is transient suppression. Thermal design focuses on minimizing inductance in the clamping path and ensuring low-impedance grounding. For repeated surge events, PCB copper area around the P4KE91H anode/cathode pads must follow TSC's recommended layout to avoid localized overheating; the P4KE91H's 175 °C TJ max allows brief thermal excursions beyond ambient limits.

Can the P4KE91H replace the P4KE91A in an existing design?

Yes - the P4KE91H and P4KE91A share identical electrical specifications except for VBR tolerance: P4KE91H is standard grade (±10%, 81.9–100 V), while P4KE91A is tighter grade (±5%, 86.5–95.5 V). Both have the same VWM (73.7 V), VC (131 V), IPPM (3.2 A), and AEC-Q101 qualification. Substitution is electrically safe, though designs relying on precise clamping onset may observe minor timing variation. No PCB changes are needed - both use DO-41 packaging and identical marking conventions (cathode band). The P4KE91H offers cost and lead-time advantages without compromising protection integrity.