MAX8896 Dual buck converter powers the WCDMA PA and RF transceiver to extend battery life in 3G handsets

Tiny, dual step-down converter integrates DC-DCs for both PA and RF transceiver.

Maxim's dual buck converter integrates a 700mA DC-DC for powering the 3G PA and a 200mA DC-DC for the RF transceiver in a tiny 4mm2 package.

SUNNYVALE, CA—February 17, 2010—Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX8896, a dual step-down converter designed for powering WCDMA/NCDMA PA (power amplifier) modules and RF transceivers. This 4mm2 device integrates a high-efficiency, PA step-down converter that is optimized for medium- and low-power transmission, and includes a bypass FET for powering the PA directly from the battery during high-power transmission. By using the MAX8896 between the battery and RF-transceiver/PA, designers can reduce current consumption by up to 50% under typical operating conditions, thus extending battery life. The MAX8896 also includes an RF step-down converter that supplies a high-PSRR, low-noise LDO (low-dropout linear voltage regulator) to provide a high-efficiency voltage supply for the RF transceiver. The MAX8896 is well suited for multiband WCDMA/NCDMA applications such as cellular handsets, netbooks, and smartphones. The MAX8896 is available in the Infineon? SMARTi? UE HSPA RF transceiver and the XMM? 6160 mobile phone platform, providing users with best-in-class battery life.

Supporting 1.9A of peak current, the integrated low-impedance 140mΩ (typ) bypass FET provides maximum power with minimum dropout, even under low-battery conditions. During high-power transmission, the bypass FET automatically turns on if the required output voltage is within 99% of the input voltage, and the PA step-down converter is forced into a 100% duty cycle.

The RF step-down converter has 94% peak efficiency with a 2MHz fixed switching frequency. It supports a 100% duty cycle, and provides a fixed 3.1V output voltage with ±2% output-voltage accuracy. The high-PSRR (65dB), low-noise (16μVRMS), 2.8V LDO delivers a guaranteed 200mA output current. The low-noise output makes this LDO ideal for RF transceiver biasing or applications that require an exceptionally clean power source.

The MAX8896 is offered in a tiny, 2mm x 2mm, 16-bump UCSP? package (0.7mm height, max) and is fully specified over the -40°C to +85°C extended temperature range. Prices start at $1.92 (2500-up, FOB USA). Samples and evaluation kits are available upon request.

Maxim Integrated Products is a publicly traded company that designs, manufactures, and sells high-performance semiconductor products. The Company was founded over 25 years ago with the mission to deliver innovative analog and mixed-signal engineering solutions that add value to its customers' products. To date, it has developed over 6200 products serving the industrial, communications, consumer, and computing markets.