The SKY77928-11 from Skyworks is a front end module that integrates power amplifiers and required switching solutions for 2G/3G/4G cellular handsets with dual antennas. Two PAs support GSM, GPRS, EDGE multi-slot operation, TD-SCDMA and TDD LTE standards. The Low Band (LB) PA transmits in the GSM 850/900 bands, the mid band (MB) PA covers the DCS 1800, PCS 1900, TD-SCDMA bands 34/39 and TDD LTE band 39. The module facilitates flexible broadband RF switch-through by 16 transmit/receive (TRx) antenna switch ports that cover all 3G/4G bands from 700 MHz through 2300 to 2700 MHz.
In support of downlink inter-band Carrier Aggregation (CA), the TRx ports are partitioned into three independent switch blocks comprising 7 LB, 5 MB and 4 HB ports with strong M/H cross-band support. Each switch block includes a directional coupler that may be monitored on the CPL port with selectable forward or reverse directionality. A diplexer and a second antenna port provide flexible simultaneous L+M/HB reception required for downlink CA.
The CMOS controller provides PA band/mode selection and bias control, including the Mobile Industry Processor Interface (MIPI) RFFE logic and switch decoder circuitry. The PA controller provides VRAMP control of the GMSK envelope and reduces sensitivity to input drive, temperature, power supply, and process variations. The Finger-Based Integrated Power Amplifier Control (FB-iPAC) minimizes output power variation into mismatch. In EDGE and TD-SCDMA / TDD LTE linear modes, VRAMP voltage and MIPI-based bias settings jointly optimize PA linearity and efficiency. It is available in a small, 44-pad configuration, 5.5 x 5.5 x 0.8 mm low profile package.
