Table of Contents
What are the two types of linear regulator?
Linear regulators exist in two basic forms: shunt regulators and series regulators. Most linear regulators have a maximum rated output current. This is generally limited by either power dissipation capability, or by the current carrying capability of the output transistor.
Do linear regulators reduce noise?
Many Linear Technology linear regulators use bipolar processes which generally have lower 1/f noise performance. Unlike a switcher, a linear regulator does not have switching noise. Other than process, linear regulator output voltage noise comes from two primary sources: the reference voltage and the error amplifier.
How efficient is a linear voltage regulator?
When the input voltage is only just above the output’s value, the linear regulator can approach 95% to 99% efficiency.
How do you design a regulator?
To select a voltage regulator for your system, start by assuming a linear regulator can be used if the input voltage is higher than the output. Only if that wastes too much power, then use a buck switching regulator. If you need an output voltage higher than the input, then use a boost switching regulator.
How much current does a linear regulator draw?
You’re using a linear regulator which simply “burns off” the excess voltage. The current does not change and remains the same so you can draw up to 1.25 A at the output of the regulator. So after the regulator you’re limited to 5 V, 1.25 A so 6.25 W.
How linear voltage regulators work?
A linear regulator employs an active (BJT or MOSFET) pass device (series or shunt) controlled by a high gain differential amplifier. It compares the output voltage with a precise reference voltage and adjusts the pass device to maintain a constant output voltage.
How do you calculate the efficiency of a linear regulator?
Efficiency of a linear regulator Since this value is small, it can be ignored when the load current is large. If this is the case, the input and output currents can be treated as being equal, and the efficiency can be calculated by simply dividing the output voltage by the input voltage.
What are the limitations of linear voltage regulators?
Disadvantages of linear regulators
- Simple.
- Cheap.
- Power supply rejection ratio. Linear regulators respond quickly to changes in input voltage, producing an output voltage that is mostly free of any ripple on the input.
- Respond quickly to changes in load voltage.
- No switching noise.
How do you calculate regulator efficiency?
Efficiency can be calculated by dividing the output power by the input power. So if the output power is the same as the input power then efficiency is 100% and the regulator wastes no power. This is the ideal, but unattainable scenario. Most switching regulators have an efficiency between 80-90%.
What are the characteristics of linear voltage regulators?
In order to obtain regulated and stable voltage, a linear voltage regulator circuit must be immune to variations and noise coming from the input. Also, it should be able to maintain the supply voltage constant for any level of power consumption. That is, the current drawn by the circuit cannot change the voltage value significantly.
What is a switching-mode voltage regulator?
Switching-mode voltage regulators are voltage converters (step-down and step-up) that uses switches to control the delivery of power to the load, and this control can be designed to set the output voltage to a specific level, independent on the input.
What are the methods of voltage regulation in power electronics?
Voltage regulation can be implemented using linear regulators and switching-mode voltage regulators.
How do I know what voltage regulator I Need?
To find out, you need to understand power dissipation and thermal resistance. At first glance, linear voltage regulators seem so simple. The part’s datasheet indicates the maximum input voltage, the maximum output current, and the output voltage (if the output is fixed rather than variable).