Diodes Incorporated ZMM5235B-7

Overview

ZMM5235B-7 from Diodes Incorporated is a 500mW surface-mount Zener diode with nominal zener voltage 6.8V (6.46–7.14V range), 5.0Ω zener impedance at 20mA, and +0.050%/°C temperature coefficient. It uses a MiniMELF glass package, supports -65°C to +175°C operation, and serves as a precision voltage reference in low-power analog power supply regulation circuits.

For engineers reviewing the ZMM5235B-7 datasheet, ZMM5235B-7 pinout, ZMM5235B-7 application, or ZMM5235B-7 equivalent, key selection factors include its tight 6.8V tolerance, low dynamic impedance, stable temperature coefficient, MiniMELF thermal performance, and suitability for space-constrained voltage clamping and reference designs.

Technical Context

This device operates as a reverse-biased silicon Zener diode optimized for stable voltage regulation at IZT = 20mA. Its 500mW power rating is valid under ambient-temperature electrode conditions, with thermal resistance RJA = 300°C/W enabling predictable derating above 25°C ambient.

The +0.050%/°C temperature coefficient ensures minimal drift over industrial temperature ranges, while its 750Ω maximum zener impedance at IZK = 0.25mA and 5.0Ω at IZT = 20mA supports both low-current biasing and moderate-load regulation roles.

Key Specifications

Pinout & Package

MiniMELF (DO-213AA) glass package: cylindrical hermetic construction with cathode band marking; terminals are solderable per MIL-STD-202, Method 208; dimensions A = 3.30–3.70 mm, B = 1.30–1.60 mm, C = 0.28–0.50 mm.

Key Features

Applications

Availability

ZMM5235B-7 is available at Aetrix Electronics and suitable for automotive engine control units, industrial sensor signal conditioning, and portable medical instrument power management requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for ZMM5235B-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, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

ZMM52xxB is part of Diodes' MiniMELF Zener diode product line, engineered for high-reliability voltage reference and regulation in space-constrained, thermally demanding applications.

FAQ

What is the maximum continuous reverse current the ZMM5235B-7 can sustain without degradation?

The ZMM5235B-7 is rated for 500 mW power dissipation at 25°C ambient with electrodes held at ambient temperature. At its nominal 6.8V zener voltage, this corresponds to a maximum continuous reverse current of approximately 73.5 mA (500 mW ÷ 6.8 V). Derating is required above 25°C per the published power vs. ambient temperature curve.

Does the ZMM5235B-7 have polarity marking, and how is it identified?

Yes - the ZMM5235B-7 features a single cathode band marking on the MiniMELF glass body, consistent with industry-standard polarity identification. The banded end is the cathode; the unmarked end is the anode. This marking is visible under standard optical inspection and aligns with MIL-STD-202 solderability requirements.

How does the +0.050%/°C temperature coefficient affect regulation accuracy over -40°C to +125°C?

Over a 165°C span (-40°C to +125°C), the total zener voltage drift is calculated as 6.8 V × 0.0005/°C × 165°C ≈ ±56 mV, or ±0.82%. This drift remains within typical system tolerances for non-critical analog references and is significantly better than generic Zeners with coefficients exceeding ±0.1%/°C.

Can ZMM5235B-7 replace ZMM5234B or ZMM5236B in existing designs?

ZMM5235B-7 has a nominal 6.8V rating versus 6.2V (ZMM5234B) and 7.5V (ZMM5236B), so direct substitution alters regulation setpoint by ±0.6–0.7V. While package and power ratings match, the voltage difference requires circuit recalibration. No electrical or thermal incompatibility exists, but functional verification is mandatory.