1SMAF4744A Independent 13.8V~15.8V 1W SMAF Zener Diodes

1SMAF4744A 15V 1W SMAF Zener Diode is a surface-mount voltage regulation component specifically designed for reliable protection and stable voltage referencing in compact electronic assemblies. This particular diode features a nominal Zener voltage (V_Z) of 15V with a tight tolerance, making it ideal for maintaining a precise voltage rail across various operating conditions. Consequently, its 1 Watt power dissipation capability allows it to handle substantial power surges and continuous regulation requirements effectively, far exceeding the capacity of standard low-power diodes. Furthermore, the low-profile SMAF package is perfectly suited for space-constrained PCBs, where high density and automated assembly are critical for modern manufacturing processes. Therefore, designers frequently specify the 1SMAF4744A when they need a rugged, high-reliability clamping and regulation solution in portable or industrial devices.

Key Features:

• High Power Dissipation: Offers a robust 1.0 Watt (1 W) maximum power dissipation rating, enabling it to absorb significant energy during transient events.
• Precision Zener Voltage: Maintains a nominal voltage of 15 V (±5% tolerance), guaranteeing tight voltage regulation for critical circuits.
• Surface Mount Package: Utilizes the low-profile SMAF (Standard Military Avionics Footprint) package, optimizing space and supporting automated pick-and-place assembly.
• Low Dynamic Impedance: Exhibits low Zener dynamic impedance (Z_Z), ensuring minimal voltage change as the operating current fluctuates.
• Wide Temperature Range: Operates reliably across an extended temperature range, suitable for industrial and demanding consumer environments.

Technical Specifications:

• Nominal Zener Voltage (V_Z): 15 V (at I_ZT = 17 mA)
• Voltage Tolerance: ±5% (denoted by ‘A’ suffix)
• Maximum Power Dissipation (P_D): 1.0 W (at T_L ≤ 75°C)
• Maximum Zener Impedance (Z_ZT): 15 Ω (at I_ZT = 17 mA)
• Maximum Reverse Leakage Current (I_R): 0.1 μA (at V_R = 10.5 V)
• Operating Junction Temperature (T_J): −55°C to +150°C

Mechanical Specifications:

• Package Type: SMAF (Surface Mount Flat Package)
• Polarity: Cathode band indicates the cathode terminal.
• Lead Finish: Matte Tin (Sn) Plated (Lead-free and RoHS compliant)
• Moisture Sensitivity Level (MSL): MSL 1 (Unlimited floor life at ≤ 30°C/85% RH)

Dimensions:

• Body Length (L): Max 2.9 mm
• Body Width (W): Max 1.9 mm
• Body Height (H): Max 1.1 mm (Low profile design)
• Terminal Width (b): ≈ 0.9 mm

Pinout and Wiring:

• Cathode (Band side): Connect to the positive voltage point or the line requiring voltage clamping/regulation.
• Anode (Non-band side): Connect to the ground reference (GND).
• Regulation Use: Wire the Zener diode in reverse bias (cathode to V+ through a current limiting resistor) to utilize its constant voltage characteristic.
• Clamping Use: Wire the Zener diode in reverse bias across the load or input to clamp voltage spikes above 15 V.

Datasheet Reference:

• Download 1SMAF4744A Zener Diode Datasheet

Commonly Used in:

• Battery Chargers: Protecting charging circuitry and providing a reference voltage for charge termination.
• Power Supplies: Establishing stable voltage references for feedback loops in regulated DC-DC converters.
• Telecom Equipment: Used in line card circuitry for surge suppression and transient voltage protection (TVS).

Applications:

• Voltage Regulation: Maintaining a steady 15V output across a variable input source when paired with a series resistor.
• Overvoltage Protection (OVP): Clamping transient voltage spikes to protect sensitive downstream components from damage.
• Signal Conditioning: Defining limits or clipping analog signals to a known voltage level for input into ADCs or comparators.

Equivalent Models:

• SMZ15B-TP (Micro Commercial Components): A high-power, 15V Zener diode in the slightly larger SMA package, which is functionally comparable.
• BZT52C15S (NXP/Diodes Inc.): A lower power (200 mW) option, however, it maintains the precise 15V nominal voltage reference.
• MMSZ5245B (ON Semiconductor): A common 15V Zener diode in the SOD-123 surface mount package, suitable for similar light-duty applications.

Package Includes:

• 1 x 1SMAF4744A Independent 13.8V~15.8V 1W SMAF Zener Diodes