How does an ultra low noise LDO work?
This ultra-low-noise LDO, the MAX6126, combines low-noise components with filtering to achieve an output noise floor of 6nV/√Hz. In Figure 1, the MAX6126 (U1) is a voltage reference whose ultra-low output noise is further reduced by a lowpass filter (R1 and C1), which attenuates noise frequencies above its approximate 0.16Hz cutoff frequency.
What’s the output noise of an ultra low noise regulator?
Abstract: This ultra-low-noise LDO combines low-noise components with filtering to achieve an output noise performance of 6nV/√Hz at 1kHz. This design idea appeared in the June 23, 2005 issue of EDN . Of the many low-dropout (LDO) regulators used to regulate voltage in electronic systems, some are specifically designed for low-noise operation.
What happens when a parallel LDO is used?
When paralleling devices, If one LDO output is at the upper value and the other is at the lower value, the paralleled LDOs will not share current; the one with the higher output voltage dominates over the entire load current range.
What is the dropout voltage of a LDO regulator?
The low dropout (LDO) linear regulator is a special type of linear regulator in which the dropout voltage—the differential between the input-to-output voltage needed to maintain regulation—is typically below 400 mV.
How is the efficiency of a LDO regulator determined?
The efficiency of an LDO Regulator is dependent on the quiescent current and input to output voltage. Efficiency is given by: By minimizing the dropout voltage as well as the quiescent current, the efficiency of LDO can be increased. It is the maximum output voltage variation for a load current step or input voltage step.
What’s the range of a low drop out regulator?
For example, a typical Li-ion battery has a range of 4.2 V at fully charged to 2.7 V at fully discharged. Even when the battery voltage is below 3 V, an LDO can still maintain the desired 2.5 V at the output. You might have seen / used several Linear Voltage Regulator ICs in your circuit design.
How does NMOS pass element based LDO work?
NMOS Pass Element based LDO is shown in the following image. The advantage of NMOS is that it is in source follower configuration and the output of the regulator is at the source of the transistor. The circuit using NMOS transistor is usually large and complex but it is possible to achieve low input, output and dropout voltage.