1N4148WS T4 SMD Switching Diode SOD-123

1N4148WS T4 SMD Switching Diode SOD-123 is a ubiquitous, high-speed switching diode renowned for its extremely fast reverse recovery time and reliable performance in high-frequency applications. Housed in the space-saving SOD-123 surface-mount device (SMD) package, the 1N4148WS offers a compelling solution for miniaturized electronics where PCB real estate is at a premium. Consequently, design engineers frequently select this component for signal limiting, fast clamping, and general-purpose switching tasks. Furthermore, its low leakage current and high voltage capability make it a robust choice for protecting sensitive circuit elements in diverse commercial and industrial environments. You can rely on the 1N4148WS (marked T4) to deliver consistent, high-speed switching across all your embedded systems.

Key Features:

• Ultra-Fast Switching Speed: Achieves a very low reverse recovery time (t_rr ≤ 4 ns), making it ideal for high-frequency signal processing and digital logic circuits.
• High Reliability: Features a high repetitive peak reverse voltage (V_RRM) of 75 V, ensuring dependable operation in demanding applications.
• Space-Saving Package: The SOD-123 surface-mount package minimizes the footprint, significantly improving component density on compact PCBs.
• Low Forward Voltage: Maintains a low forward voltage drop (V_F), thus reducing power consumption in the circuit.
• Mass-Market Standard: The 1N4148 is one of the most widely recognized and utilized switching diodes globally, guaranteeing ease of sourcing and proven stability.

Technical Specifications:

• Part Marking Code: T4
• Repetitive Peak Reverse Voltage (V_RRM): 75 V
• DC Reverse Voltage (V_R): 75 V
• Forward Continuous Current (I_F): 300 mA
• Non-Repetitive Peak Forward Surge Current (I_FSM): 1 A (t = 1s)
• Reverse Recovery Time (t_rr): Typically 4 ns max
• Operating Junction Temperature (T_j): −65°C to +150°C

Mechanical Specifications:

• Package Style: SOD-123 (Small Outline Diode)
• Mounting: Surface-Mount Device (SMD)
• Diode Type: Fast Switching Diode (Silicon Epitaxial Planar)
• Soldering Recommendation: Reflow soldering is recommended for optimal mounting and thermal performance.

Dimensions:

• Body Length (L): ≈ 2.7 mm
• Body Width (W): ≈ 1.6 mm
• Body Height (H): ≈ 1.1 mm
• Lead Material: Solderable Pads (Tinned)

Pinout and Wiring:

• Anode (A): Connect the Anode to the positive (higher potential) side of the voltage source or signal path. The marking on the body (cathode band) is away from this terminal.
• Cathode (K): Connect the Cathode (marked by a band on the diode body) to the negative (lower potential) side. Current flows from Anode to Cathode.
• Wiring Note: Ensure proper soldering reflow profiles when mounting the SOD-123 package to prevent thermal damage; observe the cathode band to correctly orient the diode in the circuit.

Datasheet Reference:

• Download ON Semiconductor 1N4148WS Datasheet

Commonly Used in:

• Digital Logic Interfaces: Essential for protecting inputs and outputs in TTL and CMOS circuits.
• SMPS (Switched-Mode Power Supplies): Utilized in small-signal feedback and control loops where fast switching is necessary.
• Portable Consumer Devices: Found in mobile phones, tablets, and wearable technology due to its small size and efficient operation.

Applications:

• Signal Clamping and Limiting: Protects integrated circuits by clamping transient voltages to safe levels.
• Reverse Polarity Protection: Prevents damage to circuits from accidentally reversed power connections. However, consider the forward voltage drop.
• High-Speed Switching: Functions as a general-purpose switch in high-frequency data and clock lines.
• Free-Wheeling Diode: Use this diode to protect transistors from back-EMF generated by inductive loads like relays and small motors.

Equivalent Models:

• 1N4148 (Through-Hole): The fundamental through-hole version, identical in electrical specification but different in package.
• LL4148 (MiniMELF): A different SMD package style, but an electrically equivalent diode.
• BAS40-04 (Schottky Diode): Offers a lower forward voltage but typically has lower reverse voltage, therefore it serves as a functional alternative in some low-power circuits.

Package Includes:

• 1 x 1N4148WS T4 SMD Switching Diode SOD-123