BAT54HT1G | Datasheet Fairchild Semiconductor

BAT54HT1G

The BAT54HT1G is a Schottky diode that comes in a small SOT-23 package, making it perfect for compact PCB designs. One of its standout features is the low forward voltage drop—typically around 0.45V at 10mA—which helps reduce power loss and improve efficiency, especially in low-voltage circuits or power supplies.

Its fast switching speed makes it great for high-frequency applications, like RF or data transmission, while its low reverse leakage current ensures reliability by minimizing energy loss. Plus, it can handle reverse voltages up to 30V, providing protection against modest voltage spikes.

It’s commonly used in power management, switching circuits, and protection circuits, helping to prevent damage from voltage spikes or ensuring stable power for sensitive devices. Its small size doesn’t sacrifice performance, making it ideal for compact devices like phones and laptops.

BAT54HT1G Pinout and Polarity

The BAT54HT1G is a Schottky diode with clear polarity. The cathode (Pin 1) has a polarity band, helping you connect it correctly. When using the diode, make sure the anode (Pin 2) goes to the positive side of your circuit, and the cathode (Pin 1) connects to the negative side or ground.

The anode is where the positive voltage goes, and current flows from the anode to the cathode when the diode is forward biased (conducting).

As a Schottky diode, the BAT54HT1G has a low forward voltage drop and quick switching speed, making it great for voltage clamping, switching, and circuit protection in low-voltage applications. Just be sure the reverse voltage doesn’t go over 30V to avoid damaging the diode.

BAT54HT1G Equivalent Schottky Diode

When comparing the BAT54HT1G and SS14, they’re pretty similar, especially in terms of forward voltage drop and reverse voltage. Both are in SOT-23 packages, so they’re easy to swap with each other. However, the SS14 can handle a bit more current (1A vs. 300mA for the BAT54HT1G), making it a better choice if you need higher current protection.

The 1N5819 could also work as a substitute, but it’s in a bigger DO-201AD package, so it takes up more space on the PCB. It can handle 1A of current and has a higher reverse voltage rating (40V), making it better for more demanding applications.

If you’re tight on space, stick with the BAT54HT1G or SS14. For higher current or reverse voltage protection, go with the SS14 or 1N5819.

BAT54HT1G Protection Circuit Schematic

This protection circuit is there to keep your components safe from high-voltage surges or wrong polarity, which could otherwise damage sensitive parts. Here’s how it works:

When the voltage across the diode hits a certain level (the forward voltage of the BAT54HT1G), the diode starts conducting and clamps the voltage, protecting the components downstream.

If a reverse voltage or surge happens, the BAT54HT1G steps in to limit the voltage, keeping it at safe levels and preventing any damage to the circuit.

BAT54HT1G Logic Level Protection

The BAT54HT1G is a great choice for logic-level protection in circuits, especially for protecting sensitive components from voltage spikes or reverse voltages. Here’s why it works well:

With a low forward voltage drop of around 0.3V, it protects circuits by allowing current to flow in only one direction and clamping the voltage to a safe level. Its fast switching speed means it can handle quick voltage changes, like those caused by spikes or ESD.

It’s also perfect for overvoltage protection: if the voltage exceeds a safe level, it’ll clamp it down to protect the circuit. And if the power supply is connected backward, it’ll block the reverse voltage, saving your components.

In short, the BAT54HT1G keeps your logic circuits safe with minimal power loss, is easy to implement, and works fast to prevent damage.

BAT54HT1G SMD Diode Wiring Guide

The BAT54HT1G Schottky diode is ideal for high-speed switching and protection in circuits. For wiring, you’ll connect the anode (Pin 2) to the positive rail or the signal you want to protect, and the cathode (Pin 1) to ground or the negative side of the circuit. This diode has a low forward voltage of 0.35V at 10mA, making it efficient by reducing power loss. It can handle reverse breakdown voltages up to 30V, which is great for typical circuit conditions. With low reverse leakage current (0.2 µA) and total capacitance (7.6 pF), it’s perfect for high-speed applications. For protection circuits, you can connect it in parallel with the load to clamp overvoltage or place it in series for reverse voltage protection. The BAT54HT1G comes in a compact SOD-23 package, so make sure your PCB is designed with the right footprint.