Characteristics and Applications of the 1SMA4749A Zener Diode

I. Characteristics

Stable Voltage Output: The 1SMA4749A Zener diode offers excellent voltage regulation, with a nominal Zener voltage of 24V and a regulation range between 22.8V and 26V, achieving a precision of ±5%. This high precision ensures that circuits receive stable voltage output in various operating environments.

SLKOR Voltage Regulator Diode 1SMA4749A product photo

Efficient Power Output: This Zener diode delivers a power output of 1W, making it suitable for applications with high power demands. Whether in devices requiring high current supply or in high-load operational states, it provides a stable and efficient voltage output.

Low Reverse Current: Under reverse voltage, the 1SMA4749A exhibits a reverse current of only 5μA@18.2V. This extremely low reverse current reduces power consumption and heat generation in the circuit, enhancing overall stability and reliability.

Slkor Voltage Regulator Diode 1SMA4749A specification

Reasonable Impedance Design: With an impedance value of 25Ω, this design helps to reduce power consumption and heat within the circuit, further boosting stability and reliability.

Wide Operating Temperature Range: Although not explicitly mentioned in the original data, Zener diodes typically feature a wide operating temperature range, and the 1SMA4749A is no exception. This allows it to operate reliably in various environments, meeting diverse application needs.

Parameters of Slkor Voltage Regulator 1SMA4749A Diode

II. Applications

Household Appliances: In devices such as TVs, washing machines, and refrigerators, the 1SMA4749A Zener diode ensures a stable power supply, protecting internal circuits from voltage fluctuations.

Communication Equipment: Stable voltage output is crucial for signal transmission and data processing in communication devices. The 1SMA4749A provides a stable voltage environment, ensuring the normal operation of communication equipment.

Automotive Electronic Systems: Various sensors, controllers, and actuators in automotive electronic systems require stable voltage supplies. The 1SMA4749A meets these needs, ensuring the stability and reliability of automotive electronic systems.

Industrial Control Systems: Voltage stability is vital for the normal operation of industrial control systems. The 1SMA4749A ensures the system receives stable voltage output under various conditions, guaranteeing stable system operation.

Power Supply Design: In power supply design, the 1SMA4749A Zener diode can be used in the voltage regulation stages of power circuits, ensuring the stability and reliability of the output voltage.

III. External Power Testing Method for Zener Diodes 

Preparation:

Select an appropriate adjustable regulated power supply for testing, with an output voltage range covering the Zener diode’s regulation range.

Prepare an appropriate current-limiting resistor, typically using a 1.5KΩ resistor.

Ready a digital multimeter for voltage measurement.

Circuit Connection:

Connect the positive terminal of the Zener diode to the negative terminal of the adjustable power supply, ensuring the current-limiting resistor is connected in series between the power supply's positive terminal and the Zener diode's negative terminal.

Connect the multimeter's positive probe to the Zener diode's positive terminal and the negative probe to the Zener diode's negative terminal.

Testing Process:

Gradually increase the output voltage of the adjustable power supply until it reaches the expected regulation range.

Read the voltage on the digital multimeter; this reading is the Zener diode's regulation value.

For more accurate results, conduct multiple measurements and average the values.

Precautions:

If the Zener diode's regulation value exceeds 15V, adjust the power supply's output voltage to above 20V accordingly.

During testing, ensure the test power supply's output voltage does not exceed the Zener diode's rated voltage to avoid damaging the device.

If the Zener diode's regulation voltage fluctuates significantly, it indicates instability in the diode's performance.