1N4746A Diode | Rectron USA

1N4746A

1n4746a

If you’re working on a project that needs a reliable voltage reference, the 1N4746A Zener diode is an excellent choice. This diode gives you a stable voltage output of around 18 volts, making it ideal for precise voltage regulation and reference circuits. It can comfortably handle power dissipation up to 1 watt, so it’s perfect for small-to-medium power applications.

The 1N4746A comes in an easy-to-use DO-41 axial package, meaning you can quickly integrate it into your circuit designs or experiment on a breadboard. It maintains consistent performance even as temperatures change, thanks to its low temperature drift—important for circuits where stability matters.

Plus, it has low reverse leakage current, keeping your circuits efficient and stable over the long run. Commonly, you’ll see it in reference voltage setups, regulated power supplies, over-voltage protection, and voltage-clamping circuits. If you need stable, accurate voltage regulation without hassle, the 1N4746A diode is a reliable and user-friendly solution.

1n4746a Pinout and Polarity

When you’re using the 1N4746A Zener diode, the first thing you’ll notice is a colored or black ring marking the cathode end—this helps you quickly identify how it should be placed in your circuit. Remember, the ringed (cathode) end connects to the higher voltage, while the other side (anode) typically goes to ground or a lower potential.

Always connect your diode in reverse bias mode, meaning the cathode faces the input voltage, and the anode connects to ground. This setup ensures a stable 18V output voltage.

Since it’s rated for 1 watt, make sure your circuit never exceeds this limit; otherwise, you could damage the diode. It’s always smart to leave some safety margin in your design.

Also, if your diode is operating close to its power limit, consider adding a heat sink or allowing for better airflow to keep temperatures under control.

When installing, axial packaging makes it easy for PCB or breadboard use—but keep soldering quick, ideally under three seconds, to prevent heat damage.

1n4746a equivalent zener diode

If you’re looking for an alternative to your 1N4746A Zener diode, there are a few things you’ll want to consider. First, think about power handling. If your circuit draws more current or needs higher power, go for something like the BZX85C18 (rated at 1.3W) or the 1N5931B (3W), since they’ll handle heavier loads safely. For lighter tasks, the 1N5248B with a lower power rating (0.5W) could save you some space and cost.

Speaking of space, the 1N5248B uses a smaller DO-35 package—ideal if you’re tight on board space. The other options like BZX85C18 or 1N5931B come in the same DO-41 package as your original diode, making it easy for a direct swap.

Always make sure the replacement diode has the same 18V rating, or your circuit’s performance might be affected. Finally, if you anticipate higher current demands, choose a diode with a higher maximum current rating like the 1N5931B. Following these guidelines will keep your circuit running smoothly and reliably.

1n4746a voltage regulator circuit

In this circuit, the 1N4746A Zener diode is used for voltage regulation. Zener diodes are typically connected in reverse bias to clamp or regulate the voltage. Here’s how it works:

The input voltage (Vin) flows into the circuit through resistor R9. Transistors Q6 and Q7 (both NPN) amplify the signal and help stabilize the output voltage, ensuring steady current flow. The 1N4746A Zener diode, connected in the circuit, limits the voltage to 18V. If the input voltage exceeds 18V, the diode uses the Zener effect to clamp the output voltage at 18V, protecting the circuit from overvoltage.

Protection diodes (D6 and D7) safeguard the circuit by preventing damage from reverse or excessive current. Finally, resistors R11 and R12 control the output voltage, ensuring it stays stable at 18V.

In summary, this design provides reliable voltage regulation using the 1N4746A Zener diode, with transistors amplifying the signal and protection diodes ensuring circuit safety. It’s perfect for voltage regulation, overvoltage protection, and power management.

1n4746a zener diode applications

The 1N4746A Zener diode is great for voltage regulation and protection in various circuits. It provides a stable 18V output by clamping the voltage when the input exceeds its breakdown voltage, making it perfect for keeping your circuits running smoothly.

For example, in a power supply that needs a constant 18V, this Zener diode can ensure that your components always get the correct voltage. It’s also great for overvoltage protection—by placing it across sensitive components, it will clamp any voltage spikes and protect your circuit.

The 1N4746A also helps suppress voltage surges, making it ideal for noisy power lines or circuits prone to transients. Plus, it can serve as a stable voltage reference in low-voltage systems, ensuring accuracy in things like analog-to-digital conversion.

In battery charging circuits, it helps prevent overcharging by limiting the voltage, and it can even reduce electrical noise in power supplies or communication systems. Overall, this Zener diode is a versatile and reliable choice for many applications.

1n4746a voltage clamp circuit

This circuit is a classic voltage clamping circuit that uses two diodes (D1 and D2) to limit the output voltage, ensuring it doesn’t exceed a set threshold. Here’s how it works:

You start with a 1kHz sine wave signal as the input (Vin), which flows through a 100kΩ resistor (R1). The two Zener diodes, D1 and D2 (here assumed to be 1N4746A), are the key components. These diodes clamp the voltage when it exceeds the Zener breakdown voltage (18V in this case).

When the input voltage goes above 18V, the diodes conduct and limit the voltage to around 18V, preventing it from rising higher. The output voltage (Vout) will stay stable, staying within the 18V limit set by the diodes.

This circuit is useful in preventing overvoltage from damaging your components by ensuring that the output signal remains within a safe, defined range.

1n4746a resistor selection guide

When using the 1N4746A Zener diode for voltage regulation, selecting the right resistors is key to ensuring the circuit runs smoothly. Here’s a simple guide for choosing your resistors.

First, you’ll need a series resistor (Rs) to limit the current through the Zener diode. You can calculate this using Ohm’s law: Rs = (Vin – Vz) / Iz, where Vin is the input voltage, Vz is the Zener voltage (18V for 1N4746A), and Iz is the current you want to flow through the diode. For example, with a 24V input and a desired current of 20mA, you’ll need a 300Ω resistor.

If you have a load, choose a load resistor (Rl) based on the output voltage and required current. For a 10mA load at 18V, a 1.8kΩ resistor works.

Remember to consider power dissipation and ensure your resistors can handle it without overheating. Also, make sure the Zener diode receives enough current to maintain regulation, typically around 5mA.