onsemi MM5Z5V1ST5G

Overview

MM5Z5V1ST5G from onsemi is a 5.1 V ±2% tolerance Zener diode in SOD-523 package, rated for 500 mW steady-state power dissipation at 25 °C, with 60 Ω max Zener impedance at 5 mA test current and 2.0 µA max reverse leakage at 3.0 V. It provides precision voltage regulation in space-constrained portable electronics such as smartphone power rails and USB interface protection circuits.

For engineers reviewing the MM5Z5V1ST5G datasheet, MM5Z5V1ST5G pinout, MM5V1ST5G application, or MM5Z5V1ST5G equivalent, key selection criteria include tight 5.1 V Zener voltage tolerance (±2%), low 225 pF capacitance at 0 V, −2.7 mV/°C temperature coefficient, ESD robustness (>16 kV HBM), and SOD-523 footprint compatibility with high-density PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode to clamp or regulate voltage with stable reference behavior across −65 °C to +150 °C junction temperature range. Its 500 mW power rating is derated linearly above 25 °C at 4.0 mW/°C, supported by 250 °C/W junction-to-ambient thermal resistance on FR-4 board.

The device features low dynamic impedance (60 Ω max at I_ZT = 5 mA) and minimal capacitance (225 pF max at 0 V, 1 MHz), enabling effective noise suppression and fast transient response in low-voltage DC bias networks. Its 100% matte tin lead finish and MSL 1 rating ensure reliable reflow soldering at up to 260 °C.

Key Specifications

Pinout & Package

SOD-523 surface-mount package: 1.20 mm × 0.80 mm body, 0.60 mm height, void-free thermosetting plastic case with 100% matte tin leads. Qualified for MSL 1 and 260 °C reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C5V1 and MMBZ5221BS, MM5Z5V1ST5G delivers tighter voltage tolerance (±2% vs. ±5%), higher power handling (500 mW vs. ≤350 mW), and optimized SOD-523 footprint-making it the preferred choice for miniaturized, high-reliability 5 V regulation where thermal and space margins are constrained.

Availability

MM5Z5V1ST5G is available at Aetrix Electronics and suitable for smartphone power rail protection, USB 2.0 data line clamping, and IoT sensor node reference applications requiring stable component supply and consistent parametric performance across production lots.

Supply support for MM5Z5V1ST5G 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MM5ZxxxST5G series belongs to onsemi's Tight Tolerance Zener Regulator product line, engineered specifically for space-constrained, high-reliability voltage reference and overvoltage protection in portable and battery-powered electronics.

FAQ

What is the Zener voltage tolerance of MM5Z5V1ST5G?

The MM5Z5V1ST5G has a nominal Zener voltage of 5.1 V with a tight tolerance of ±2%, meaning its actual breakdown voltage falls between 4.98 V and 5.20 V when tested at 5 mA. This specification is guaranteed per the onsemi datasheet revision 15 and applies across the full operating temperature range. The MM5Z5V1ST5G achieves this precision through process-controlled doping and laser trimming during manufacturing.

Is MM5Z5V1ST5G suitable for USB 2.0 data line protection?

Yes, MM5Z5V1ST5G is suitable for USB 2.0 data line protection due to its low 225 pF capacitance at 0 V and 1 MHz, which avoids signal integrity issues at 480 Mbps data rates. Its 5.1 V breakdown voltage clamps transients before damaging downstream PHY circuitry, and its >16 kV HBM ESD rating meets IEC 61000-4-2 Level 4 requirements. The MM5Z5V1ST5G is typically used in pairs (D+/D− to VBUS or 3.3 V rail) in certified USB designs.

What is the maximum power dissipation of MM5Z5V1ST5G at 85 °C ambient?

At 85 °C ambient temperature, the MM5Z5V1ST5G's maximum power dissipation is reduced to 260 mW. This is calculated using the 4.0 mW/°C derating factor from the 500 mW rating at 25 °C: (85 − 25) × 4.0 = 240 mW reduction, leaving 260 mW. This value assumes mounting on an FR-4 board with a 1 cm² copper pad, per the datasheet Note 1. The MM5Z5V1ST5G's thermal resistance (R_JA = 250 °C/W) confirms this linear derating behavior.

Does MM5Z5V1ST5G have automotive qualification?

No, MM5Z5V1ST5G is not AEC-Q101 qualified. Only variants with the "SZ" prefix (e.g., SZMM5Z5V1ST5G) are specified for automotive applications and meet AEC-Q101 stress testing and PPAP requirements. The MM5Z5V1ST5G is intended for commercial and industrial use. For automotive-grade equivalents, select the SZMM5Z5V1ST5G variant, which shares identical electrical specs but adds automotive-specific traceability and change control.

What is the cathode marking convention for MM5Z5V1ST5G in SOD-523 package?

The cathode of MM5Z5V1ST5G is marked by a polarity band located adjacent to Pin 1 on the SOD-523 package body. Per onsemi mechanical drawing 98AON11524D, the marking diagram shows "XX M" where "XX" is the device code (TA for 5.1 V) and "M" is the date code; the microdot or band is positioned near Pin 1. This band must align toward the higher-potential node (e.g., VBUS) when installed as a shunt regulator. The MM5Z5V1ST5G's cathode-anode orientation is critical for proper reverse-bias operation.