Taking an input voltage of 1.7 to 5.5V and available with outputs from 1.2 to 3.6V (11 versions), the RP124 low supply current LDO regulator features an ultra-low current consumption of only 0.3µA (at no-load), extending the lifetime of battery powered devices. Typically, to measure the remaining battery charge, engineers use an external resistor divider + MOSFET connected to an A/D Converter.
However, the input impedance of this solution is typically low, resulting in a considerable current flow to ground, draining the battery and limiting the lifetime of the application. The RP124 provides a simple solution with a built-in resistor divider and voltage follower as a buffer.
This circuit has a much lower current flow to ground and the output is compatible with the input impedance of the A/D converter. In addition, all essential components for this circuit are integrated into the chip, reducing valuable circuit board space and cost.
The device switches automatically between a low power consumption and a fast transient response mode, based on the output current demand of the application. Ripple rejection as well as the response speed to line and load transients demonstrate better results compared to a conventional LDO with low current consumption.
This means the RP124 contributes to optimized output voltage stability and ripple reduction. The Off Mode is controlled by the Chip Enable pin and turns the LDO offline, reducing current consumption to a minimum.
The RP124 features an embedded fold back current limit circuit. When a short circuit occurs at the output, this circuit will decrease the output current to a level of 65mA, thus protecting the LDO and other electronic parts of the application from possible damage. After removing the short, the regulator resumes to normal operation automatically. The chip comes in a standard SOT-23-5 or compact DFN1212-6
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