BAT54S Schottky Diode Structure, Technical Parameters, Package and Other Details
14 November 2023
Ⅱ. BAT54S symbol, footprint and pin configuration
Ⅲ. Structure and working principle of BAT54S diode
Ⅳ. What are the features of BAT54S diode?
Ⅴ. Technical parameters of BAT54S diode
Ⅵ. What are the advantages and disadvantages of BAT54S diode?
Ⅶ. Dimensions and package of BAT54S diode
Ⅷ. What are the applications of BAT54S diode?
In this article, you'll be acquainted with the BAT54S Schottky diode, a versatile component with distinctive features and a broad spectrum of applications. Exploring its unique features and practical uses will provide you with a comprehensive understanding, enabling more effective integration into real-world projects.
BAT54S is a Schottky diode, named after its inventor Dr. Schottky. SBD is the abbreviation of Schottky Barrier Diode. It consists of three independent PN junctions, including two forward biased diodes and a small reverse biased diode. BAT54S features fast switching speed and low reverse leakage current, making it widely used in high-frequency circuits and switching circuits. Due to its fast switching speed, it is often used for the detection and amplification of high-frequency signals. In addition, its low reverse leakage current characteristics also make it advantageous in precision measurement circuits and low-power applications.
Replacements and equivalents:
The following are the symbol, footprint and pin configuration of BAT54S diode.
The BAT54S device consists of three PN junctions, two N-type semiconductors are anodes, and the middle P-type semiconductor is a cathode. When forward biased, the P-type semiconductor in the middle forms a PN junction with the N-type semiconductors at both ends. At this time, electrons flow from the N-type semiconductor to the P-type semiconductor, and holes flow from the P-type semiconductor to the N-type semiconductor, so current can pass through. When reverse biased, the P-type semiconductor in the middle forms a PN junction with the N-type semiconductor at both ends. At this time, electrons flow from the P-type semiconductor to the N-type semiconductor, and holes flow from the N-type semiconductor to the P-type semiconductor. But because of the potential barrier, the current cannot pass through. BAT54S has unidirectional conductivity, which makes it suitable for use in rectification, protection, etc.
1. Positive characteristics
In electronic circuits, when the anode of a diode is connected to a high potential end and the cathode is connected to a low potential end, the diode will conduct. This connection is called forward biased. It should be noted that the diode can conduct well only when the forward voltage applied to both ends of the diode is large. In addition, when the voltage is low, the diode will not conduct easily, and the current flowing through the diode is also very weak.
Only when the forward voltage reaches a certain value (approximately 0.1V for germanium tubes and approximately 0.5V for silicon tubes) does the diode truly conduct. After it is turned on, the voltage across the diode remains basically unchanged (approximately 0.3V for germanium tubes and approximately 0.7V for silicon tubes), which is called the "forward voltage drop" of the diode.
2. Reverse characteristics
In electronic circuits, when the positive pole of the diode is connected to the low potential end and the negative pole is connected to the high potential end, the diode will be in a cut-off state, and there will be almost no current flowing through it. This connection method is called reverse bias. When the diode is in reverse bias, there will still be a weak reverse current flowing through the diode, known as leakage current.
When the reverse voltage across the diode increases to a certain value, the reverse current will increase sharply. At this time, the diode will lose its unidirectional conductive characteristics. This state is called the breakdown phenomenon of the diode.
1. Advantages of BAT54S
(1) Good high temperature characteristics: It can work normally at higher temperatures and has good thermal stability.
(2) Small size: It adopts micro package and is small in size, suitable for use in compact circuit board designs.
(3) Fast switching speed: It has a fast switching speed and can complete on and off switching within nanoseconds.
(4) Clamp protection: It can realize clamp protection of the output voltage and protect the subsequent circuit from being affected by the input signal.
(5) High reliability: The BAT54S utilizes a Schottky structure, featuring low reverse leakage current and high withstand voltage characteristics. This enhances the circuit's reliability and stability.
(6) Low power consumption: Its turn-on voltage is low, usually around 0.7V, so it can achieve higher efficiency in low-voltage applications.
2. Disadvantages of BAT54S
(1) A more complex control circuit is required: BAT54S has fast switching speed and high temperature characteristics, so a more complex control circuit is required to realize its function. This may increase design difficulty and cost.
(2) Higher price: Compared with ordinary diodes, its price is higher, which may increase the cost of the entire circuit.
(3) Lower surge current withstanding capability: BAT54S has a lower surge current withstanding capability, which may limit its use in certain applications.
(4) Higher driving voltage: While its activation voltage is lower, its operational voltage is higher, potentially impacting certain low-voltage systems.
The BAT54S measures 2.92 mm in length, 1.3 mm in width, and 0.93 mm in height. Enclosed in an SOT-23 package, this compact package facilitates the creation of high-density circuit layouts within confined spaces.
1. Voltage limitations in circuits
The BAT54S can be used as a voltage limiting element to limit the voltage in a circuit below its maximum rating. For example, in an LED drive circuit, we need to ensure that the operating voltage of the LED is within a safe range. At this time, we can use BAT54S as a voltage limiter to limit the LED's operating voltage below its maximum rating, thereby effectively protecting the LED from overvoltage damage.
2. Rectification in the circuit
BAT54S can be used as a rectifier diode to convert alternating current into direct current. For example, in an audio amplifier, we need to remove the AC component of the input signal and retain the DC component. In this case, we can use BAT54S as a rectifier diode.
3. Reverse protection in the circuit
In electronic circuits, we often need to provide reverse protection for devices in the circuit to prevent damage to the circuit due to excessive reverse voltage. At this time, we can use BAT54S as a reverse protection diode. When the reverse voltage exceeds the maximum rating of the BAT54S, it limits the voltage below its maximum rating, thereby protecting the devices in the circuit.
Frequently Asked Questions
1. What is the BAT54S?
The BAT54S is a surface mount Schottky barrier diode that is widely used in electronic circuits for rectification and signal demodulation.
2. What is the main advantage of Schottky diode?
One of the primary advantages of using a Schottky diode over a regular diode is its low forward voltage drop. This allows a Schottky diode to consume less voltage than a standard diode, using only 0.3-0.4V across its junctions.
3. In what applications is BAT54S commonly used?
BAT54S is often used in applications such as rectification, signal demodulation, and switching due to its low forward voltage drop and fast switching characteristics.
4. What is a Schottky diode used for?
Schottky diodes are used as switches in fast-clamp diode applications. In this application, the base junction is forward biased. With Schottky diodes, the turn-off time is significantly reduced and the speed of the circuit is increased.
5. What is the Schottky diode and how it works?
The schottky diode is a type of metal–semiconductor junction diode, which is also known as hot-carrier diode, low voltage diode or schottky barrier diode. The schottky diode is formed by the junction of a semiconductor with a metal. Schottky diode offers fast switching action and has a low forward voltage drop.
