Diodes Incorporated ZMM5253B-7

Overview

ZMM5253B-7 from Diodes Incorporated is a 25 V, 500 mW surface-mount Zener diode in MiniMELF (DO-213AA) glass package, with nominal zener voltage tolerance ±5% (23.75–26.25 V @ 5.0 mA), 35 Ω dynamic impedance at test current, and +0.089 %/°C temperature coefficient. It provides precision voltage reference and overvoltage clamping in low-power analog circuits, power supply feedback loops, and ESD protection interfaces.

For engineers reviewing the ZMM5253B-7 datasheet, ZMM5253B-7 pinout, ZMM5253B-7 application, or ZMM5253B-7 equivalent, key selection criteria include its 25 V nominal zener voltage, 5.0 mA test current, 35 Ω zener impedance, -65 to +175 °C operating range, and MiniMELF mechanical compatibility with automated SMT placement.

Technical Context

This device operates as a two-terminal voltage-regulating diode, conducting in reverse breakdown at precisely controlled zener voltage under specified test conditions (IZT = 5.0 mA). Its hemispherical glass MiniMELF package enables stable thermal performance with 300 °C/W junction-to-ambient thermal resistance and supports pulsed operation up to 100 ms.

The ZMM5253B-7 exhibits a positive temperature coefficient of +0.089 %/°C, indicating increasing zener voltage with rising temperature - a critical factor when used in temperature-sensitive references or compensation networks where drift must be modeled or canceled.

Key Specifications

Pinout & Package

Package: MiniMELF (DO-213AA) - hermetically sealed glass cylindrical package, 3.3–3.7 mm length × 1.3–1.6 mm diameter, cathode band marking, solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX55C24 and MMSZ5253B, the ZMM5253B-7 offers superior thermal performance (300 °C/W), hermetic reliability, and MiniMELF SMT compatibility - making it optimal for high-reliability industrial and automotive applications demanding stable 25 V referencing.

Availability

ZMM5253B-7 is available at Aetrix Electronics and suitable for power supply feedback, overvoltage clamp, temperature-compensated reference, and low-power analog calibration requiring stable component supply and traceable sourcing.

Supply support for ZMM5253B-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 industrial, automotive, and computing markets.

The ZMM52xxB series targets precision voltage regulation in space-constrained, thermally demanding applications - designed specifically for MiniMELF SMT deployment where hermetic stability and tight VZ tolerance are essential.

FAQ

What is the maximum continuous reverse current before breakdown for ZMM5253B-7?

The maximum reverse current before breakdown is defined by IR = 0.1 µA at VR = 19 V (76% of nominal VZ). This ultra-low leakage ensures minimal loading on bias networks and preserves accuracy in high-impedance reference nodes, especially critical in battery-powered systems where standby current must be minimized.

Can ZMM5253B-7 be used in place of a 24 V Zener diode?

No - ZMM5253B-7 is specified at 25 V nominal (23.75–26.25 V range), not 24 V. Substituting it for a 24 V part introduces a systematic 1 V offset that will degrade regulation accuracy in feedback or clamp circuits. For 24 V applications, ZMM5252B (24 V) or BZX55C24 should be used instead.

Is the MiniMELF package compatible with standard reflow profiles?

Yes - the MiniMELF (DO-213AA) package is qualified for lead-free reflow per J-STD-020, with peak temperatures up to 260 °C. Its glass body withstands thermal shock better than plastic SOD packages, but requires careful profile tuning to avoid cracking due to rapid ramp rates or uneven heating across the small cylindrical geometry.

How does the +0.089 %/°C temperature coefficient affect circuit design?

This positive TC means VZ increases by ~22.25 mV per °C rise (0.089% × 25 V). In precision references, it must be compensated - e.g., by pairing with a negative-TC component like a forward-biased diode or NTC thermistor - or accepted as a known, linear drift term in calibration algorithms for measurement systems operating across wide temperature ranges.