## How do I choose a LDO regulator?

The input voltage range determines the maximum and minimum allowable input supply for the LDO. Input supplies that are higher than the maximum allowable input can damage the LDO. The lowest input supply must be higher than the LDO output voltage plus the dropout voltage.

**What is the difference between LDO and voltage regulator?**

An LDO regulator is a linear regulator that can operate at a very low potential difference between the input and output voltage. A linear regulator is a type of power supply IC that can output a steady voltage from an input voltage and is used in a variety of electronic devices.

**Can LDO boost voltage?**

Both LDO and boost output voltages are programmable using external resistors. The boost preregulator output voltage is adjustable up to 11V (MAX5092_), or up to 12V (MAX5093_).

### What is LDO efficiency?

LDO efficiency. With Iq in the denominator, it is evident that the higher Iq, the lower the efficiency. Today’s LDOs have reasonably low Iq, and for simplicity, Iq can be neglected in efficiency calculations if Iq is very small compared to ILOAD. Then LDO efficiency is simply (Vo/Vin)*100%.

**What is Ground pin current in LDO?**

Ground current (IGND) is the difference between the input and output currents, and necessarily includes the quiescent current. A low ground current maximizes the LDO efficiency.

**How does a LDO work?**

LDO is a linear voltage regulator that has a small voltage drop between the input and the output, and it works well even when the output voltage is very close to the input voltage unlike the linear voltage regulator that requires a large voltage drop between the input and the output to work properly.

## Why LDO is needed?

LDO regulators are used to derive lower output voltages from a main supply or battery. The output voltage is ideally stable with line and load variations, immune to changes in ambient temperature, and stable over time.

**What is drop out voltage in LDO?**

Dropout Voltage. Dropout voltage is the input-to-output differential voltage at which the circuit ceases to regulate against further reductions in input voltage; this point occurs when the input voltage approaches the output voltage. Figure 1 shows a typical LDO regulator circuit.

**How does LDO calculate power consumption?**

The LDO is dissipating (Vin – Vout) x Iout as heat. In your application this is (3.7 V – 3.3 V) x 30 mA = 12 mW. When you combine these two together you see that 12 mW + 629 uW = 12.629 mW is being consumed within the LDO.

### How is LDO input current calculated?

Suppose that you want to use an LDO regulator at VOUT = 1.2 V and IOUT = 500 mA. In this case, the maximum dropout voltage is 150 mV. Hence, Minimum input voltage = 1.2 V + 0.15 V = 1.35 V Therefore, input voltage must be 1.35 V or higher, and VBIAS must be over 3.3 V.