Contents
What are the requirements for a transistor circuit?
Choose a transistor of the right type (NPN or PNP from step 1) to meet these requirements: The transistor’s minimum current gain hFE(min) must be at least 5 times the load current Ic divided by the maximum output current from the IC. max.
When to use a lithium ion battery protection circuit?
A battery protection circuit should be used to prevent this. Lithium batteries are completely empty when discharged to 2.5 V/cell. Discharging a lithium cell this low is stressful to the cell and reduces cell lifetime. A good battery protection circuit will also provide over-discharge protection.
Which is a key element of a battery protection circuit?
A key element of a battery protection circuit are the MOSFETs used to switch the cell in and out of the circuit. MOSFETs with low RDS(ON) should be used to achieve high efficiency. Use MOSFETs with low Vt because the battery protection IC may only have 2–3 V to drive the gate.
Which is better for reverse polarity protection diode or p channel MOSFET?
That’s why using a P-Channel MOSFET for Reverse Polarity Protection is far better than other methods. It is little bit costlier than diode but it makes the protection circuit much safer and efficient. We have also used a Zener Diode and a resistor in the circuit for the protection against exceeding gate to source voltage.
When does no current flow through a transistor?
If the base-emitter voltage is below 0.7 V, the transistor is in “cutoff” and no current flows through the emitter or through the collector. That’s it. That’s how a BJT works. The collector-emitter current flow is inherent in the construction of the transistor.
How does a transistor switch off the collector current?
The transistor amplifies this small current to allow a larger current to flow through from its collector (C) to its emitter (E). This collector current is large enough to make LED C light brightly. When the switch is open no base current flows, so the transistor switches off the collector current.
Which is the base current in a transistor?
The diagram shows the two current paths through a transistor. You can build this circuit with two standard 5mm red LEDs and any general purpose low power NPN transistor (BC108, BC182 or BC548 for example). The small base current controls the larger collector current.
There can be a number of parameters required in the requirements for the transistor circuit design: Voltage gain: The voltage gain is often a key requirement for electronic circuit design. The voltage gain of the circuit is the increase in voltage from the input to the output of the circuit.
How are field effect transistors used in electronics?
The circuits often follow proven circuits that have been used for many years. These circuits have often been used with the old vacuum tube or thermionic valve technology and work equally well with bipolar transistors as well as field effect transistors, FETs, and sometimes even operational amplifiers.
What are the advantages of using a transistor?
The advantage of a transistor is that you can use a small current or voltage to control a much larger current and voltage. That’s super useful if you want to control things like motors, high-power LEDs, speakers, relays, and more from a Raspberry Pi/Arduino/microcontroller.
How are the topologies of a transistor circuit chosen?
Transistors circuits can be designed using different topologies, each one offering different characteristics, especially in terms of the input and output impedance. These topologies of configurations are chosen according to the electronic circuit design requirements and include common emitter, common collector or emitter follower, and common base.