RF PA 1A Buck DCDC converter

The NCP6361, a PWM synchronous step-down DC-to-DC converter, is optimized for supplying RF Power Amplifiers (PAs)used into 3G/4G wireless systems (Mobile / Smart Phones, Tablets, ...) powered by single-cell Lithium-Ion batteries. The device is able to deliver up to 2A current in bypass mode and 800 ma in buck mode. The output voltage is monitorable from 0.4V to 3.5V by an analog control pin VCON. The analog control allows dynamically optimizing the RF Power Amplifiers efficiency during a communication while for example in roaming situation or when transmitting data with as a benefit an increased talk time. Also at light load for optimizing the DC-to-DC converter efficiency, the NCP6361 enters automatically in a PFM mode and operates in a slower switching frequency. On the other side the NCP6361 enters in bypass mode when the desired output voltage becomes close to the input voltage (e.g.: low battery conditions). The device operates at 3.429 MHz or 6 MHz switching frequency. This way the system tuning can focus respectively either on a better efficiency 3.249 MHz or on employing smaller value inductor and capacitors 6 MHz. By the way, synchronous rectification offers improved system efficiency. The NCP6361 has two versions: NCP6361A and NCP6361B. The version B has a spread-spectrum function for low EMI operation. The NCP6361 is available in a space saving, low profile 1.36 x 1.22 mm CSP-9 package.