1N4738UR-1

Overview

The Microchip Technology 1N4738UR-1 is a Zener diode voltage regulator designed for surface-mount applications. It features a DO-213AA-2 (SMB) package and supports a power dissipation of 1 W. The device operates within an extended temperature range from -65 °C to +175 °C, ensuring reliability in harsh environments. Key electrical characteristics include a nominal Zener voltage of 8.2 V with a tolerance of ±5%. The component exhibits a maximum reverse leakage current of 10 µA and a Zener impedance of 4.5 Ω at the test current of 31 mA. Forward voltage is specified at 1.2 V.

Feature Summary

• Surface-mount construction in a compact DO-213AA-2 package for automated assembly
• Extended thermal stability supporting operation up to +175 °C
• High power handling capability rated at 1 W dissipation
• Tight voltage tolerance of ±5% for precise regulation

Applications

• Voltage reference circuits requiring high thermal stability
• Overvoltage protection in industrial control systems
• Power supply regulation modules
• Clamping applications in automotive electronics

Procurement Notes

Verify the specific suffix UR-1 against official Microchip documentation to confirm package type and compliance status. Ensure the procurement channel provides valid traceability for the DO-213AA-2 form factor. Cross-reference the manufacturer part number with authorized distributor databases to validate authenticity and avoid counterfeit components. Confirm RoHS and REACH compliance details directly from the latest datasheet revision.

Selection Notes

Select this component when a 1 W surface-mount Zener diode with high-temperature capability is required. The 8.2 V nominal voltage and ±5% tolerance suit precision regulation tasks. Compare the DO-213AA-2 footprint against available PCB space. Evaluate the 4.5 Ω impedance and 10 µA leakage against circuit sensitivity requirements. Consider the -65 °C to +175 °C range for environmental suitability.

Part Context

This device belongs to the 1N47xx series of Zener diodes manufactured by Microchip Technology. The series offers various voltage ratings and power dissipation levels. The UR-1 suffix typically denotes a specific surface-mount packaging variant, distinguishing it from through-hole equivalents like the 1N4738G or axial reel versions such as 1N4738ATR. This family is widely used in general-purpose voltage regulation and protection applications.

Replacement Considerations

Direct substitutes include the onsemi 1N4738ATR for axial configurations, though package differences require layout adjustments. Microchip's 1N4738G serves as a through-hole alternative. Verify pinout compatibility and thermal resistance characteristics when replacing with other manufacturers' 1W Zener diodes in the SMB package.