ST offers a wide range of low and medium power LDO regulators featuring ultra-low dropout and fast transient response characteristics. Low Dropout Regulators (LDO Regulators)are available at Mouser Electronics from industry leading manufacturers. Mouser is an authorized distributor for many. ST's low dropout (LDO) regulators offer an optimal combination of low dropout voltage, low quiescent current, fast transient response, low noise and good ripple.


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Low-dropout regulator - Wikipedia

This is one of the parameters that could impact the circuit architecture that is chosen for the output power delivering stage. Smaller dropout voltages often mean a p-type output pass element, which is inherently ldo regulator in size than the corresponding n-type stage for a given load current.

Quiescent Current System power efficiency as well as battery life is greatly impacted by the quiescent current, IQ, and the shutdown, or leakage current, ISD. Further, these usually scale with load current, becoming larger when the Ldo regulator is delivering full power.

This is to keep the output power device from saturating the loop internally.

The LDO will remain stable for all load conditions up to the maximum-rated current. Further, good stability at zero load current enables the system to continue to operate for disabled loads, thus removing latency and delays in the system. Output Accuracy and Load Regulation Ldo regulator voltage accuracy measures the regulation accuracy of the feedback loop and load regulation indicates the drive capability of the regulator in ldo regulator load current changes.

Over-temperature ldo regulator circuits are typically included in systems that deal with moderate to high power levels. The maximum ambient operating temperature will be based on the load current and the voltage drop across the device.

LDO Linear Regulators | Analog Devices

Equation 1 is used to calculate the maximum power dissipation of the device based on the load conditions. Equation 3 can then be used to calculate the maximum junction temperature for a given thermal impedance of the junction to the board. Equation 3 These calculations are usually key to ensuring the system ldo regulator deliver maximum power, without causing thermal issues.

Selecting the right ldo regulator is very important in this context.


Due to practical limitations, such as finite loop gain and finite ldo regulator bandwidth, as ldo regulator as parasitic leakage paths from the input to the output, the output voltage will have a component that is dependent on the input line, albeit attenuated in magnitude and shifted in phase.

Ldo regulator, due to the finite closed-loop output impedance of the regulator, the output voltage will vary a little bit due to load changes. The DC component is just the load line measured at the output, while the transient part is a function of the output capacitance present at the load point and the closedloop bandwidth of the amplifier, as well as the rate at which the load current is changed.

There will also be a strong dependence on how the input line is supplied to the regulator, with the input Power Delivery Network PDN inductance and decoupling playing a key role in the regulator output. Care must be taken to ensure that any package resonance is kept well outside the frequency band of interest.


Output Noise The integrated output noise of the regulator is usually determined by the noise of the reference input, the closed-loop gain of the regulator, ldo regulator the noise ldo regulator the input stage of the error amplifier.

These need to be budgeted and designed to a given noise specification. Essentially, PSRR is a measure of how much the output voltage moves for a given perturbation on the input. A 20 dB rejection means a 10X attenuation ldo regulator the line noise to what is seen at the output.

For most LDOs, this falls off rapidly with higher frequencies because of the characteristics of the control loop.

A careful analysis of the various poles and zeros of the loop filter is required, and this analysis is typically the most complex part of the design of an LDO, requiring a significant amount of design time.

Low-dropout regulator

Such LDOs are called output-compensated regulators. The exact capacitor values depend on several factors such as ldo regulator current, headroom available, and others. These capacitors help with sourcing or sinking surge currents ldo regulator to fast load changes.