Diodes Incorporated ZMM5252B-7

Overview

ZMM5252B-7 from Diodes Incorporated is a 500mW surface-mount Zener diode with a nominal zener voltage of 24V (22.8–25.2V range), 5.2mA test current, 33Ω dynamic impedance at I_ZT, and +0.087%/°C temperature coefficient. It uses a MiniMELF glass package for precision voltage reference in low-power analog circuits and power supply feedback loops.

For engineers reviewing the ZMM5252B-7 datasheet, ZMM5252B-7 pinout, ZMM5252B-7 application, or ZMM5252B-7 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (300°C/W), reverse leakage (<0.1µA at 18V), junction capacitance (~18pF), and stability under transient thermal conditions.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to maintain stable DC voltage across its terminals. Its zener mechanism dominates above ~5V, delivering predictable regulation with low dynamic impedance (33Ω at 5.2mA) and minimal voltage drift over temperature (+0.087%/°C).

The MiniMELF hermetic glass package ensures reliable long-term stability and low leakage, while the 500mW power rating and 300°C/W junction-to-ambient thermal resistance define safe operating limits under continuous DC or pulsed conditions (100ms pulse width per test).

Key Specifications

Pinout & Package

Two-terminal device in MiniMELF (JEDEC DO-213AA) hermetic glass package. Cathode identified by single band marking. No internal leads or multi-pin configuration.

Key Features

Applications

Availability

ZMM5252B-7 is available at Aetrix Electronics and suitable for industrial power supplies, automotive sensor modules, test equipment calibration circuits, and LED driver feedback networks requiring stable component supply and long-term parametric consistency.

Supply support for ZMM5252B-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for power management, signal integrity, and protection applications.

ZMM52xxB belongs to Diodes' MiniMELF Zener diode product line, engineered for precision voltage reference and regulation in space-constrained, thermally demanding environments where hermetic stability and tight tolerances are essential.

FAQ

What is the maximum continuous reverse voltage this diode can withstand without breakdown?

The ZMM5252B-7 is designed to operate in controlled reverse breakdown at its specified zener voltage. Its absolute maximum reverse voltage rating is not defined separately - operation above 25.2V (max V_Z) increases power dissipation and thermal stress beyond design limits. Sustained reverse voltage exceeding 25.2V without current limiting risks irreversible degradation.

How does the +0.087%/°C temperature coefficient affect performance in a 0–70°C ambient range?

Over 0–70°C, the zener voltage shifts by approximately +0.087%/°C × 70°C = +6.09%, or +1.46V from 24V nominal. This results in a final V_Z range of ~24.3–25.7V. For applications requiring tighter stability, external compensation or selection of lower-TC alternatives (e.g., ZMM5240B at +0.075%/°C) may be necessary.

Can this diode replace a through-hole 1N4749A in a PCB redesign?

No - the ZMM5252B-7 (MiniMELF, DO-213AA) and 1N4749A (DO-41) differ in package size, thermal resistance (300°C/W vs ~150°C/W), and mounting method. While both are 24V Zeners, the MiniMELF's smaller footprint and higher R_JA require revised PCB layout, thermal relief, and current-limiting resistor recalculations to avoid overheating.

Is the cathode band polarity consistent across all ZMM52xxB series devices?

Yes - all ZMM52xxB devices use unidirectional cathode band marking per JEDEC DO-213AA standard. The band always identifies the cathode terminal, and orientation is identical across the full series (ZMM5221B to ZMM5267B). This ensures consistent placement and soldering direction in automated assembly.