Diodes Incorporated DDZX5V1B-7

Overview

DDZX5V1B-7 from Diodes Incorporated is a surface-mount precision Zener diode with nominal zener voltage 5.1 V (4.94–5.20 V range), 300 mW power dissipation on FR-4 PCB, and tight 5% tolerance at 20 mA test current. It delivers sharp breakdown characteristics, low leakage (5 μA @ 1.5 V reverse), and is qualified to AEC-Q101 for automotive-grade reliability.

For engineers reviewing the DDZX5V1B-7 datasheet, DDZX5V1B-7 pinout, DDZX5V1B-7 application, or DDZX5V1B-7 equivalent, this part is selected for voltage reference, overvoltage protection, and biasing in space-constrained, high-stability analog circuits where low temperature coefficient and minimal zener impedance (17 Ω @ 20 mA) are critical.

Technical Context

This Zener operates in reverse-biased breakdown mode with tightly controlled V_Z and low dynamic impedance (Z_ZT = 17 Ω, Z_ZK = 480 Ω), enabling stable regulation across load and line variations. Its thermal resistance (R_θJA = 417 °C/W) and derating curve support operation up to +150 °C ambient when mounted per recommended SOT23 pad layout.

The device exhibits very low reverse leakage (I_R = 5 μA @ V_R = 1.5 V) and forward voltage of 0.9 V @ 10 mA, making it suitable for bidirectional clamping and precision reference generation in low-power sensor interfaces and ADC reference buffers.

Key Specifications

Pinout & Package

Package: SOT23 - 3-terminal surface-mount plastic package with matte tin annealed terminals, UL 94V-0 rated molding compound, and moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C5V1 and MMSZ5222BS, DDZX5V1B-7 uniquely balances AEC-Q101 qualification, 17 Ω zener impedance, and 5 μA leakage-making it optimal for automotive and medical applications demanding both reliability and precision under thermal stress.

Availability

DDZX5V1B-7 is available at Aetrix Electronics and suitable for industrial sensor conditioning, automotive ECU reference design, and medical device bias supply applications requiring stable component supply and long-term lifecycle assurance.

Supply support for DDZX5V1B-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 automotive, industrial, and computing markets.

This part belongs to the DDZX series of precision Zener diodes, designed specifically for applications demanding tight voltage tolerance, low leakage, and AEC-Q101-compliant reliability in harsh environments.

FAQ

What is the maximum reverse voltage (V_R) before significant leakage occurs in DDZX5V1B-7?

At V_R = 1.5 V, reverse leakage is specified at 5 μA maximum. Beyond this, leakage rises exponentially; operation above 1.5 V in reverse bias is not recommended unless used in controlled Zener breakdown mode at or above 4.94 V. The device is not rated for blocking voltages between 1.5 V and 4.94 V.

Can DDZX5V1B-7 be used in parallel for higher power dissipation?

No-parallel connection is not recommended due to mismatch in zener voltage (4.94–5.20 V range) causing current hogging. Even minor V_Z differences result in one device conducting >90% of total current, exceeding its 300 mW rating. Use a single higher-power Zener or active regulation instead.

Is the SOT23 pinout compatible with standard Zener footprints like DO-35 or SMA?

No-SOT23 is a 3-pin surface-mount package with specific 0.915 mm pitch and pin 1/anode orientation. DO-35 and SMA are axial/lead-based packages with different thermal and mechanical behavior. Direct footprint substitution is not electrically or thermally valid; board layout must match SOT23 dimensions and recommended pad layout (X=0.8 mm, Y=0.9 mm).

Does DDZX5V1B-7 require external series resistance in all applications?

Yes-when used as a shunt regulator, a series current-limiting resistor is mandatory to set I_Z ≥ 1 mA and prevent thermal runaway. For example, with 12 V input and 5.1 V output, a 330 Ω resistor limits I_Z to ~21 mA, staying within 300 mW and ensuring stable regulation at 20 mA test point.