onsemi MM3Z43VC

Overview

MM3Z43VC from onsemi is a 43 V ±5% tolerance Zener diode in SOD−323FL package, rated for 200 mW power dissipation, with 141 Ω zener impedance at 2 mA test current and 0.045 µA reverse leakage at 30.1 V. It provides precision voltage regulation in low-power reference and protection circuits.

For engineers reviewing the MM3Z43VC datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal resistance (595 °C/W), junction temperature limit (150 °C), reverse leakage at VR, and SOD−323FL footprint compatibility with high-density PCB layouts.

Technical Context

The MM3Z43VC operates as a two-terminal voltage reference device, conducting in reverse breakdown to maintain stable 43 V across its terminals under controlled current conditions. Its zener voltage is specified at IZT = 2 mA with ±5% tolerance and tested under 10 ms pulse conditions.

It exhibits 141 Ω dynamic impedance (ZZT) at 2 mA and 353 Ω knee impedance (ZZK) at 0.5 mA, with reverse leakage limited to 0.045 µA at VR = 30.1 V. Thermal performance is defined by RJA = 595 °C/W when mounted on PCB with minimum land pad.

Key Specifications

Pinout & Package

SOD−323FL surface-mount package (Case 477AB), 1.7 mm × 1.25 mm × 0.95 mm, matte tin finish, Pb-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MM3Z43VC, BZX384-B43 offers higher power headroom at identical footprint but shifts optimal bias point, while MMSZ43ET1G trades miniaturization for robustness and ease of integration in non-space-constrained designs.

Availability

MM3Z43VC is available at Aetrix Electronics and suitable for industrial sensor reference, microcontroller reset circuit, and low-power voltage monitor applications requiring stable component supply, consistent parametric performance, and RoHS-compliant sourcing.

Supply support for MM3Z43VC 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

onsemi (Semiconductor Components Industries, LLC) is a global supplier of energy-efficient semiconductor solutions, serving automotive, industrial, cloud, medical, and IoT markets with differentiated silicon and system-level expertise.

The MM3Z series targets space-constrained, low-power voltage regulation and protection applications, delivering tight-tolerance Zener performance in the industry's smallest standard SMD package for modern portable and embedded systems.

FAQ

What is the zener voltage tolerance of MM3Z43VC?

The MM3Z43VC has a nominal zener voltage of 43 V with a tolerance of ±5%, meaning its actual breakdown voltage falls between 40.85 V and 45.15 V when tested at IZT = 2 mA under pulse conditions. This tolerance is confirmed in the onsemi datasheet Rev. 3 (August 2023) and applies across the full operating temperature range. The MM3Z43VC maintains this specification without requiring external calibration or trimming.

What package type does MM3Z43VC use?

MM3Z43VC uses the SOD−323FL surface-mount package (Case 477AB), measuring 1.7 mm × 1.25 mm × 0.95 mm with matte tin finish. It is Pb-free and RoHS compliant. This ultra-compact footprint is verified in the mechanical drawings section of the official onsemi datasheet and is distinct from larger variants like SOD-123 or DO-35. The MM3Z43VC's marking "ZX" appears adjacent to the cathode band on the device body.

What is the maximum power dissipation for MM3Z43VC?

The MM3Z43VC has a maximum power dissipation (PD) of 200 mW at TA = 25 °C, as specified in the Absolute Maximum Ratings table. Derating is required above 25 °C at 0.337 mW/°C (based on RJA = 595 °C/W). This value is measured with the device mounted on a PCB using minimum land pad, and it directly limits usable zener current in continuous operation. The MM3Z43VC must be thermally managed accordingly in enclosed or high-ambient environments.

How does the zener impedance of MM3Z43VC affect circuit performance?

The MM3Z43VC exhibits a maximum zener impedance (ZZT) of 141 Ω at IZT = 2 mA, which governs how tightly it regulates voltage under small-signal AC load variations. Lower ZZT improves rejection of ripple and noise on the regulated node. At lower currents (e.g., IZK = 0.5 mA), impedance rises to 353 Ω, so stable regulation requires maintaining sufficient bias current. This behavior is documented in the Electrical Characteristics table and impacts MM3Z43VC's suitability for precision reference versus coarse clamp applications.

What is the reverse leakage current of MM3Z43VC at its rated voltage?

The MM3Z43VC specifies a maximum reverse leakage current (IR) of 0.045 µA at VR = 30.1 V, per the Electrical Characteristics table. This ultra-low leakage ensures minimal parasitic current draw in high-impedance monitoring or battery-backed circuits. It is measured at TA = 25 °C and remains well below 100 nA across the full operating temperature range. For designs relying on MM3Z43VC as a voltage threshold detector, this parameter directly affects trip-point accuracy and long-term stability.