RE025

RE025 is a Low Drop Out (LDO) voltage regulator macrocell with programmable 2.8Vor 2.9V output voltages, rated for loads of up to 30 mA. RE025 is designed to be integratedwith other analog cells, digital logic, microcontrollers, DSP cores and memory blocksinto system-on-chip products.

The circuit RE025 consists of a PMOS pass device, an error amplifier and a feedback resis-tive network, sized to achieve the required closed loop gain. These blocks of RE025 make upthe regulating loop. An over-current and short circuit protection circuit has beenincluded to limit the output current delivered by the regulator, thus avoiding destructionin case of a short circuit.

An external reference voltage (bandgap voltage)RE025 is necessary for correct functionality.The target reference voltage of RE025 is 1.231V, delivered, for example, by BG019. Doublepads on the supply voltage VBAT3A/VBAT3AA and output voltage VPLLA/VPLLAA are used toreduce the total output resistance. Current reference of RE025 is generated inside the cellthrough a circuit supplied by a 2.5V ± 0.1V regulated input voltage on VSAUVC. Remotesense terminal VPLLS provides regulation at the load by connecting it to the output ter-minal near a critical point to improve performance of the regulator (e.g., connectingthem at the package pin by double-bonding thus avoiding the bonding resistance influ-ence). A ceramic capacitor of 2.2 µF connected from VPLLA/VPLLAA to ground is neededas external compensation.