onsemi 1.5KE9.1AG

Overview

1.5KE9.1AG from ON Semiconductor is a unidirectional 1500 W transient voltage suppressor (TVS) diode designed for parallel clamping protection of sensitive electronics against ESD, lightning surges, and inductive switching transients. It features a 9.1 V nominal breakdown voltage (V_BR), 13.4 V maximum clamping voltage (V_C) at 112 A peak pulse current (I_PP), and <1 ns response time - deployed in power supplies, industrial controls, and medical equipment input stages.

For engineers reviewing the 1.5KE9.1AG datasheet, pinout, applications, or equivalent options, key selection criteria include working peak reverse voltage (7.78 V), low zener impedance, UL 497B recognition for isolated loop circuits, and Pb-free axial lead (Case 41A) compatibility with through-hole reflow and wave soldering.

Technical Context

The 1.5KE9.1AG operates as a silicon avalanche diode configured in unidirectional mode, with cathode band marking polarity. Its clamping action begins at V_BR = 8.65–9.55 V (tested at I_T = 1 A), limiting transient energy by diverting surge current to ground while maintaining V_C ≤ 13.4 V at I_PP = 112 A (10/1000 µs waveform). Thermal resistance is 20 °C/W (junction-to-lead), enabling 5.0 W steady-state dissipation at T_L ≤ 75 °C.

It meets Class 3 ESD immunity (>16 kV HBM), exhibits <5 µA leakage above 10 V, and supports non-repetitive surge duty cycles per Figure 7 derating curves. The device is not intended for bidirectional or AC-line protection without external circuitry and requires series impedance (Z_in) to limit fault current during clamping.

Key Specifications

Pinout & Package

1.5KE9.1AG uses an axial-leaded, Pb-free Surmetic plastic package (Case 41A), with cathode identified by a colored band. Leads are tin-plated, solderable at 260 °C for 10 s at 1/16″ from case.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ9.0A, the 1.5KE9.1AG delivers 15× higher surge power handling and superior thermal dissipation via axial leads, while 1N6267AG offers identical performance in JEDEC-mandated labeling - making it a seamless drop-in alternative for documentation or procurement alignment.

Availability

1.5KE9.1AG is available at Aetrix Electronics and suitable for industrial power supplies, medical instrumentation, programmable logic controllers, and process control systems requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for 1.5KE9.1AG 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

ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensors, and discrete devices for automotive, industrial, and cloud power applications.

The 1.5KE9.1AG belongs to the 1.5KE Series Mosorb TVS family, engineered for high-reliability transient suppression in harsh electromagnetic environments where UL 497B compliance and repeatable clamping performance are mandatory.

FAQ

What is the clamping voltage of the 1.5KE9.1AG under maximum surge conditions?

The 1.5KE9.1AG has a maximum clamping voltage (V_C) of 13.4 V when subjected to its rated peak pulse current of 112 A (10/1000 µs waveform). This value is measured per Figure 5 test conditions and ensures downstream circuitry remains within safe operating voltage limits during transient events. The 1.5KE9.1AG achieves this clamping performance while maintaining low dynamic impedance and sub-nanosecond response.

Can the 1.5KE9.1AG be used for bidirectional transient protection?

The 1.5KE9.1AG is a unidirectional TVS diode and is not inherently bidirectional. However, it can be used in a bidirectional configuration by connecting two units in series opposition (cathode-to-cathode or anode-to-anode), enabling symmetrical clamping for AC or floating signal lines. This arrangement doubles the effective V_WM and must account for combined V_C and layout parasitics. The 1.5KE9.1AG itself does not provide intrinsic bidirectional behavior.

Is the 1.5KE9.1AG RoHS compliant and halogen-free?

Yes, the 1.5KE9.1AG carries the "G" suffix indicating a Pb-free, RoHS-compliant construction per ON Semiconductor's specifications. The device uses a void-free, thermosetting plastic package (Case 41A) with tin-plated leads and conforms to J-STD-020 moisture sensitivity level 1. Halogen content is not explicitly stated in the datasheet, but ON Semiconductor's standard Surmetic axial packages meet IEC 61249-2-21 requirements for chlorine and bromine limits.

What is the maximum steady-state power dissipation for the 1.5KE9.1AG?

The 1.5KE9.1AG has a steady-state power dissipation (P_D) rating of 5.0 W at lead temperature (T_L) ≤ 75 °C with 3/8″ lead length. Above 75 °C, it derates linearly at 20 mW/°C. This rating assumes adequate PCB copper area or heatsinking; actual dissipation depends on thermal path efficiency. The 1.5KE9.1AG is not intended for continuous forward conduction - its primary function is transient clamping, not DC regulation.

Does the 1.5KE9.1AG require external series impedance in circuit design?

Yes, the 1.5KE9.1AG requires external series impedance (Z_in) between the protected line and the TVS to limit peak current during clamping and prevent device overstress. Without Z_in, surge energy may exceed the 1500 W rating or cause thermal runaway. Typical values range from 1–10 Ω for low-voltage DC lines, selected based on source impedance, expected surge magnitude, and acceptable voltage drop. Layout best practices also mandate minimal lead length to reduce inductive overshoot in the 1.5KE9.1AG protection path.