Microchip Technology SMAJ4763E3/TR13

Overview

SMAJ4763E3/TR13 from Microsemi (now Microchip Technology) is a 2 W surface-mount silicon Zener diode with nominal zener voltage 91 V ±5%, 2.8 mA test current, 250 Ω dynamic impedance at I_ZT, and 50 mA peak surge current rating. It serves as a precision voltage regulator or overvoltage clamp in DC power supply feedback loops and transient protection circuits.

For engineers reviewing the SMAJ4763E3/TR13 datasheet, SMAJ4763E3/TR13 pinout, SMAJ4763E3/TR13 application, or SMAJ4763E3/TR13 equivalent, key selection criteria include zener tolerance (±5%), thermal resistance (25 °C/W), steady-state power dissipation (2.0 W), and DO-214AC package compatibility with automated SMT assembly.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable reference voltage under varying load and temperature conditions. Its 91 V nominal zener voltage is specified at 2.8 mA test current (I_ZT) with 250 Ω dynamic impedance (Z_ZT), ensuring predictable regulation behavior in feedback networks.

Designed for surface-mount use in DO-214AC (SMAJ) package, it supports high-surge-current capability (50 mA per half-sine pulse) and operates across -55 °C to +150 °C junction temperature range. Polarity is marked by cathode band; soldering requires ≤260 °C for 10 seconds.

Key Specifications

Pinout & Package

DO-214AC (SMAJ) surface-mount package with molded plastic body, flat handling surface for accurate placement, and cathode band marking polarity. Terminals are solderable per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode applications.

Compared with SMAJ4763E3/TR13, 1N4763A offers identical regulation performance but requires through-hole assembly, while MMSZ5263B-TP sacrifices power and surge capability for smaller size-making SMAJ4763E3/TR13 optimal for SMT-based 2 W clamping where thermal and surge robustness are critical.

Availability

SMAJ4763E3/TR13 is available at Aetrix Electronics and suitable for industrial power supply regulation, automotive ECU voltage reference, and telecom line card protection requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for SMAJ4763E3/TR13 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

Microsemi (acquired by Microchip Technology in 2018) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components.

The SMAJ47xxA series was developed for surface-mount Zener regulation in harsh-environment power systems, emphasizing thermal robustness, surge resilience, and JEDEC-compliant electrical equivalence to legacy 1N47xxA devices.

FAQ

What is the zener voltage tolerance for SMAJ4763E3/TR13?

The SMAJ4763E3/TR13 has a nominal zener voltage of 91 V with a tolerance of ±5%, as indicated by the absence of a tolerance suffix (e.g., 'C' for ±2% or 'D' for ±1%). This tolerance is verified at 2.8 mA test current and thermal equilibrium conditions per the official datasheet MSC0284A.

Is SMAJ4763E3/TR13 compatible with reflow soldering processes?

Yes, SMAJ4763E3/TR13 is qualified for standard SMT reflow processes. Its DO-214AC package supports soldering at up to 260 °C for 10 seconds, meeting IPC-J-STD-020 moisture sensitivity level (MSL) requirements when handled per manufacturer guidelines. The flat top surface ensures reliable pick-and-place accuracy.

How does the thermal resistance of SMAJ4763E3/TR13 affect its power handling?

The SMAJ4763E3/TR13 has a junction-to-lead thermal resistance (R_θJL) of 25 °C/W, measured with 4.0 mm² copper pads per terminal. This means that at 100 °C lead temperature, the device must be derated linearly from 2.0 W to zero power at 150 °C junction temperature-critical for thermal design in enclosed or high-ambient environments.

Can SMAJ4763E3/TR13 replace 1N4763A in existing designs?

SMAJ4763E3/TR13 is electrically equivalent to 1N4763A per datasheet MSC0284A, sharing identical zener voltage, test current, dynamic impedance, and surge rating. However, its DO-214AC surface-mount package requires PCB layout changes-no direct pin-to-pin replacement without footprint adaptation.

What is the maximum reverse current specification for SMAJ4763E3/TR13?

At the rated zener voltage of 91 V, SMAJ4763E3/TR13 exhibits a maximum reverse current (I_R) of 5 µA when tested at V_R = 73.7 V (81% of V_Z). This leakage value ensures minimal power loss in high-impedance bias networks and stable reference behavior in precision analog circuits.