onsemi MM5Z9V1ST1

Overview

MM5Z9V1ST1 from onsemi is a 9.1 V ±4.2% Zener diode in SOD−523 package, rated for 200 mW steady-state power dissipation at 25°C with 160 Ω maximum Zener impedance at 5 mA test current and 0.5 μA reverse leakage at 6.0 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 MM5Z9V1ST1 datasheet, pinout, applications, or equivalent options, key selection criteria include its 9.1 V nominal Zener voltage, ±4.2% tolerance, 160 Ω dynamic impedance at I_ZT, 16 kV HBM ESD rating, and SOD−523 footprint compatibility with high-density PCB layouts.

Technical Context

This device operates as a two-terminal voltage reference using avalanche breakdown in silicon PN junction. Its 9.1 V nominal Zener voltage is specified at 5 mA test current (I_ZT), with temperature coefficient of +3.8 mV/°C and maximum capacitance of 130 pF at 0 V and 1 MHz.

The SOD−523 package enables surface-mount assembly with 1.20 mm × 0.80 mm body outline and 0.7 mm height. Thermal resistance is 635 °C/W junction-to-ambient on FR-4 board, supporting derated operation up to 150°C junction temperature.

Key Specifications

Pinout & Package

SOD−523 is a two-terminal surface-mount package with cathode marked by a band. Terminal 1 is cathode; Terminal 2 is anode. No internal circuitry - direct connection to Zener junction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C9V1 and MMSZ5240B, MM5Z9V1ST1 offers the smallest PCB area (1.20 mm × 0.80 mm) and tightest V_Z tolerance (±4.2%), making it optimal for next-generation wearables and miniaturized USB-C accessories where layout density and accuracy are critical.

Availability

MM5Z9V1ST1 is available at Aetrix Electronics and suitable for smartphone power rail protection, USB 2.0 data line clamping, and wearable sensor bias reference applications requiring stable component supply and consistent parametric performance across production lots.

Supply support for MM5Z9V1ST1 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MM5ZxxxST1 series is designed specifically for ultra-compact voltage regulation and ESD protection in portable electronics, emphasizing minimal footprint, high reliability, and Pb-free compliance.

FAQ

What is the nominal Zener voltage and tolerance of MM5Z9V1ST1?

The MM5Z9V1ST1 has a nominal Zener voltage of 9.1 V with a tolerance of ±4.2%, specified at 5 mA test current (I_ZT). This means the actual measured V_Z falls between 8.85 V and 9.23 V under standard conditions. The tight tolerance supports precise voltage clamping without calibration, and the value is guaranteed across the full operating temperature range of −65°C to +150°C. MM5Z9V1ST1 maintains this specification in its SOD−523 package with no derating required below 25°C ambient.

What is the maximum power dissipation and thermal derating behavior of MM5Z9V1ST1?

MM5Z9V1ST1 is rated for 200 mW steady-state power dissipation at 25°C ambient on an FR-4 board. It derates linearly at 1.5 mW/°C above 25°C, reaching zero dissipation at approximately 158°C ambient. Its junction-to-ambient thermal resistance is 635 °C/W, meaning a 200 mW load generates ~127°C junction-to-ambient delta-T. MM5Z9V1ST1 remains within safe operating limits up to +150°C junction temperature, verified per its qualified MSL 1 reflow profile.

Does MM5Z9V1ST1 meet RoHS and Pb-free requirements?

Yes, MM5Z9V1ST1 is fully compliant with RoHS Directive 2011/65/EU and is Pb-free. Its lead finish is 100% matte tin, and the epoxy molding compound meets UL 94 V-0 flammability rating. The "T1" suffix denotes the standard Pb-free version, and the device carries no exemptions. MM5Z9V1ST1 supports lead-free reflow profiles up to 260°C peak temperature and satisfies JEDEC J-STD-020 moisture sensitivity level 1 (unlimited floor life).

What is the Zener impedance and how does it affect transient response in MM5Z9V1ST1?

MM5Z9V1ST1 has a maximum Zener impedance (Z_ZT) of 160 Ω at I_ZT = 5 mA, and Z_ZK = 15 Ω at I_ZK = 1 mA. This low dynamic impedance ensures minimal voltage variation during fast current transients - for example, a 100 mA surge causes only ~16 mV shift in clamping voltage. MM5Z9V1ST1's 160 Ω Z_ZT directly enables sub-100 mV overshoot control in smartphone power rail protection, where rapid response to ESD or load-dump events is essential.

How is the polarity and marking identified on MM5Z9V1ST1 in the SOD−523 package?

MM5Z9V1ST1 uses standard SOD−523 polarity marking: the cathode is indicated by a visible band at one end (Terminal 1), and the anode is the unmarked end (Terminal 2). The device marking "TK" appears adjacent to the cathode band. When mounted, the banded end must connect to the more positive potential to achieve reverse-bias Zener operation. MM5Z9V1ST1 has no internal polarity reversal - correct orientation is mandatory for proper voltage regulation, and reverse installation will result in forward conduction at ~0.9 V instead of 9.1 V breakdown.