Overview: RAA212831
4.5V to 72V Input, 0.5A Buck Regulator with Two Linear Regulator Outputs Datasheet The RAA212831 is a triple output regulator combining a 4.5V to 72V input, 0.5A buck regulator with two LDO outputs. The buck regulator has a fixed switching frequency of 350kHz in Continuous Conduction mode (CCM) and operates in pulse skipping mode at lighter loads when it enters Discontinuous Conduction mode (DCM). The two LDOs operate from a 12V (or lower) input voltage. The LDOs are rated at 100mA and 50mA of output current. The buck regulator output can be set from 1.25V to VIN×Dmax. The LDOs can support an input voltage range of 6V to 12V and the output voltages are fixed at 3.3V and 5V. The IC is designed to provide a compact, highly integrated power management solution. Its integrated buck regulator and LDO outputs minimize system component count. The buck converter uses peak current mode control, providing 500mA current for load and downstream LDO regulators, while the LDOs provide 5V and 3.3V regulated outputs for the system. The current-mode buck converter provides a fast transient response and cycle-by-cycle switching current limit. All output voltages are fixed internally with few external components required. At light load or no-load operation on the buck regulator output, the RAA212831 operates in a pulse skipping mode in DCM. When the output load is increased, and the buck regulator enters CCM, the controller operates at 350kHz. The RAA212831 offers comprehensive protection including UVLO, high-side overcurrent, output undervoltage, and over-temperature protection. The device is available in SOIC8-E package.
