Low Noise Micro PMU, 3 A Buck Regulator with 3 A LDO

The ADP5003 integrates a high voltage buck regulator and an ultralow noise low dropout (LDO) regulator in a small, 5 mm × 5 mm, 32-lead LFCSP package to provide highly efficient and quiet regulated supplies

The buck regulator is optimized to operate at high output currents up to 3 A. The LDO is capable of a maximum output current of 3 A and operates efficiently with low headroom voltage while maintaining high power supply rejection.

The ADP5003 can operate in one of two modes. Adaptive mode allows the LDO to operate with an optimized headroom by adjusting the buck output voltage internally in response to the LDO load current. Alternatively, the ADP5003 can operate in independent mode, where both regulators operate separately from each other, and where the output voltages are programmed using resistor dividers.

The LDO regulator output can be accurately controlled at the point of load (POL) using remote sensing that compensates for the printed circuit board (PCB) trace impedance while delivering high output currents.

Each regulator is activated via a dedicated precision enable input. The buck switching frequency can be synchronized to an external signal, or programmed with an external resistor.

Safety features in the ADP5003 include thermal shutdown (TSD), input undervoltage lockout (UVLO) and independent current limits for each regulator. The ADP5003 is rated for a −40°C to +125°C operating junction temperature range.

APPLICATIONS

* Low noise power for high speed analog-to-digital converter (ADC) and digital-to-analog converter (DAC) designs

* Powering RF transceivers and clocking ICs

* Low noise, dc power supply system

* High efficiency buck for first stage conversion

* High PSRR, low noise LDO regulator to remove switching ripple

* Adaptive LDO regulator headroom control option for optimal efficiency and PSRR across full load range

* Precision enable inputs for both the buck regulator and LDO

* 3 A, low noise, buck regulator

* Wide input voltage range: 4.2 V to 15 V

* Programmable output voltage range: 0.6 V to 5.0 V

* 0.3 MHz to 2.5 MHz internal oscillator

* 0.3 MHz to 2.5 MHz SYNC frequency range