BAT54A – SMD Schottky Diode

22 November 2018 - 0 Comments

BAT54A Schottky Diode

BAT54A Pinout

BAT54A is a Schottky Barrier Diode only available in SMD (Surface Mount Device) package which offers low turn ON voltage drop and fast switching capability. The device is designed with PN Junction Guard Ring for transient and ESD protection and is also RoHS compliant ‘Green’ device.

Pin Configuration

It has three terminals as shown in the BAT54A pin diagram.

Pin	Name	Function
3	Anode	Common Anode for the two schottky diodes in the device. The current flows in to the device from this pin.
2	Cathode 2	Cathode for second schottky diode in the device. The current flows out from the device through this pin.
1	Cathode 1	Cathode for first schottky diode in the device. The current flows out from the device through this pin.

BAT54A Features and Electrical characteristics

Low forward voltage drop
Very small conduction losses
Extremely fast switching speed
High efficiency
Totally lead-free and RoHS complaint device
Maximum forward continuous current: 200mA
Maximum forward surge current: 600mA
Maximum reverse voltage: 30V
Operating temperature range: -65ºC to 150ºC
Maximum power dissipation: 200mW

Similar ICs

BAT54, BAT54C, BAT54S

BAT54A Overview

BAT54A is basically used in low voltage rectifier and protection circuits. The device being designed to have low voltage drop during conduction will become necessary in low voltage circuits where conduction voltage drop cannot be afforded.
BAT54A is used in circuits where power efficiency is important. The device being capable of carrying sizable currents while having low drop will lead to high efficiency which is a necessity in battery operated systems.
BAT54A is designed to be capable of recovering (from forward conduction to blocking reverse voltage) taking only 5nS so that it can be operated high frequency applications.

How to use BAT54A Schottky Diode

BAT54A can be operated like any other rectifier diode and can be installed in rectifier and protection circuits. With that the characteristics of BAT54A can be given as:

Conducts in forward bias direction (Anode connected to positive voltage and Cathode connected to ground)
Only leakage current up to 0.1mA flows in the reverse direction (Cathode connected to positive voltage and Anode connected to ground)
During forward bias a maximum of 1V appears across the device and during reverse bias total supply voltage appears across the device.

BAT54A Schottky Diode Circuit

In the above circuit BAT54A is used as a protection diode for the microcontroller. Here the power supply unit delivers power Microcontroller while diode in series is for protection.

Working of circuit

When the supply unit delivers power the diode gets forward biased and current starts flowing. Because of current flow a voltage appears at the Microcontroller and this voltage will be very near to PSU voltage because the device has very low drop during forward conduction.
Now for an instant consider the PSU polarity is connected wrongly. Under such state the diode gets reverse biased and based on BAT54A characteristics no current flows through the circuit during reverse bias. So under error connection there will be zero voltage appearing across the Microcontroller thus saving it from damage.

In the above circuit BAT54A protects sensitive Microcontroller from reverse voltage and in a similar way we can use the device in other application circuits.