Diodes Incorporated MMBZ5258BS-7-F

Overview

MMBZ5258BS-7-F from Diodes Incorporated is a dual isolated 36 V ±5% Zener diode pair in SOT-363 package, rated for 200 mW total power dissipation, 3.4 mA test current, and 70 Ω dynamic impedance at 1 kHz; used for precision voltage reference and overvoltage clamping in space-constrained analog signal conditioning circuits.

For engineers reviewing the MMBZ5258BS-7-F datasheet, MMBZ5258BS-7-F pinout, MMBZ5258BS-7-F application, or MMBZ5258BS-7-F equivalent, key selection factors include nominal Zener voltage tolerance (±5%), low leakage (<0.1 µA @ 27 V), thermal resistance (625 °C/W), and dual-diode isolation for bidirectional clamping or dual-rail reference generation.

Technical Context

This dual-Zener device integrates two electrically isolated 36 V Zener junctions in a single SOT-363 package, enabling symmetrical clamping or independent reference functions without cross-coupling. Each diode operates with a specified test current of 3.4 mA and exhibits 70 Ω impedance at 1 kHz under standard conditions.

The device complies with RoHS and Diodes Inc.'s "Green" policy, uses matte tin plating on Alloy 42 leadframe, and is rated for operation from –65 °C to +150 °C with moisture sensitivity level 1 per J-STD-020D.

Key Specifications

Pinout & Package

SOT-363 surface-mount package with six terminals: two anodes (A1, A2), two cathodes (C1, C2), and two no-connect (NC) pins. Molded plastic case meets UL 94V-0 flammability rating; polarity defined by top-view schematic showing C1–A1–C2–A2–NC–NC sequence.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C36LT1G and MMBZ5258B-7-F, MMBZ5258BS-7-F uniquely delivers two isolated 36 V Zeners in one ultra-small package-critical for compact dual-rail protection or matched reference pairs where substrate coupling must be avoided.

Availability

MMBZ5258BS-7-F is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB port protection, PLC I/O modules, and automotive body control units requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MMBZ5258BS-7-F 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 centers across Asia and manufacturing in China, Taiwan, and Malaysia.

This part belongs to the MMBZ52xxBS series of dual-Zener diodes designed specifically for high-density, low-power voltage regulation and transient suppression in portable and industrial electronics.

FAQ

What is the maximum reverse leakage current for MMBZ5258BS-7-F?

The maximum reverse leakage current is 0.1 µA at 27 V, measured at 25 °C ambient. This value reflects the device's ability to maintain high-impedance behavior in standby mode, critical for low-power reference applications where leakage could shift bias points or drain battery reserves.

Can MMBZ5258BS-7-F be used for bidirectional ESD protection?

Yes - its dual isolated Zener structure allows one diode to clamp positive transients to ground and the other to clamp negative transients to VCC, forming a symmetric ±36 V clamping network ideal for differential data lines like RS-485 or CAN bus stubs.

Is thermal derating required for continuous operation above 25°C?

Yes - the device's 625 °C/W thermal resistance necessitates linear derating beyond 25 °C ambient. At 75 °C ambient, maximum allowable power drops to 100 mW, per the derating curve in Figure 1 of DS31039 Rev. 15-2.

How does the SOT-363 package affect PCB layout for optimal thermal performance?

Optimal thermal performance requires using the recommended pad layout from Diodes Inc. Application Note AP02001: 0.65 mm wide × 1.9 mm long copper pads per terminal, with thermal vias under the center paddle (if present) and minimum 25 mm² copper area per side to achieve full 200 mW rating.