Diodes Incorporated DFLZ20-7

Overview

DFLZ20-7 from Diodes Incorporated is a 1.0W surface-mount power Zener diode in PowerDI123 package, rated for 20V nominal Zener voltage (18.8–21.2V range) at 25mA test current, with 15Ω maximum Zener impedance and ±0.06%/°C temperature coefficient. It delivers stable voltage regulation in power supply feedback loops, overvoltage protection circuits, and reference voltage generation for industrial power converters.

For engineers reviewing the DFLZ20-7 datasheet, DFLZ20-7 pinout, DFLZ20-7 application, or DFLZ20-7 equivalent, key selection criteria include its 1.0W FR-4 PCB power dissipation, cathode-band polarity marking, JEDEC-qualified reliability, automotive-grade variant availability (DFLZ20Q), and thermal resistance of 9°C/W junction-to-soldering-point.

Technical Context

This Zener diode operates in reverse breakdown to maintain precise DC voltage under varying load and line conditions. Its low 15Ω dynamic impedance ensures minimal output voltage deviation across 5–100mA operating current, while the ±0.06%/°C temperature coefficient enables stable regulation from –55°C to +150°C ambient.

The PowerDI123 package integrates a copper leadframe with matte tin annealed terminals, achieving 110°C/W junction-to-ambient thermal resistance on standard FR-4 PCBs and 9°C/W junction-to-soldering-point - critical for high-reliability power management in space-constrained designs.

Key Specifications

Pinout & Package

Package: PowerDI123 - surface-mount plastic package with exposed cathode tab for thermal and electrical connection; dimensions: 1.78mm × 3.70mm × 0.98mm (L×W×H); weight ≈ 0.01g; UL 94V-0 rated molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C20 and 1N4744A, DFLZ20-7 uniquely combines 1.0W surface-mount capability, JEDEC reliability validation, and halogen-free construction - making it the preferred choice for new industrial and automotive-adjacent power designs requiring long-term supply stability and thermal robustness.

Availability

DFLZ20-7 is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, and precision voltage reference designs requiring stable component supply, JEDEC-qualified reliability, and RoHS3-compliant materials.

Supply support for DFLZ20-7 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, manufacturing, and sales operations across Asia, Europe, and North America.

The DFLZ series belongs to Diodes' Power Discrete product line, engineered specifically for high-reliability voltage regulation and protection in industrial, computing, and communications power systems - emphasizing thermal efficiency, JEDEC qualification, and environmental compliance.

FAQ

What is the maximum continuous reverse current the DFLZ20-7 can sustain without degradation?

The DFLZ20-7 is rated for 1.0W power dissipation on FR-4 PCB, corresponding to ~50mA continuous reverse current at 20V (P = V × I). Derating is required above +25°C ambient per Figure 1's power derating curve - at +85°C, maximum sustainable current drops to ~33mA to maintain junction temperature ≤150°C.

Does the DFLZ20-7 have an automotive-qualified version?

Yes - the DFLZ20Q is the AEC-Q200 qualified variant, sharing identical electrical specifications and PowerDI123 packaging but subjected to additional stress testing including temperature cycling, humidity bias, and mechanical shock per automotive reliability standards.

How is polarity identified on the DFLZ20-7 package?

Polarity is marked by a cathode band on the top surface of the PowerDI123 package, aligned with the cathode terminal. The band corresponds to the larger, exposed copper tab on the bottom side - this tab must be soldered to the PCB's cathode net and serves as the primary thermal conduction path.

Can DFLZ20-7 replace 1N4744A in existing designs without layout changes?

No - although both are 20V, 1.0W Zeners, DFLZ20-7 uses PowerDI123 (1.78mm × 3.70mm), while 1N4744A uses DO-41 (2.7mm × 5.2mm). Pad layout, stencil aperture, and reflow profile must be updated; however, thermal performance improves due to lower R_θJS (9°C/W vs. ~40°C/W for DO-41).