SKY74138

• Polar Loop transmitter on a single chip
• No delay adjustment required
• Meets AM suppression requirements without calibration
• Direct connection to single cell lithium ion battery
• Low external component count

RF Transceiver for Multi-Band GSM, GPRS, and EDGE Applications

The SKY74138 RF transceiver is a highly integrated device formulti-band Global System for Mobile Communications (GSM),General Packet Radio Service (GPRS), and/or Enhanced Data Ratefor GSM Evolution (EDGE) applications. The device supportsGSM850, EGSM900, DCS1800, and PCS1900 applications.

The receive path of SKY74138 implements a direct down-conversionarchitecture. The DCR? consists of four integrated Low NoiseAmplifiers (LNAs), a quadrature demodulator, selectablebandwidth baseband filters, and a low-droop DC Offset Correction(DCOC) sequencer. Similar to its predecessors, Skyworksinnovative direct conversion architecture allows for this highlyintegrated SKY74138 to be combined with virtually any standardGSM/EGPRS baseband without requiring any special processinginterfaces.

The SKY74138, together with the SKY77523 transmit/receiveFront-End Module (FEM), form the Helios? II-Plus EDGE RFSubsystem. Feedback signals from the SKY77523 to theSKY74138 form an integral portion of the Skyworks Polar Loop?transmit architecture. This architecture autonomously adjustsamplitude and phase transmit signals using separate controlloops. The filter-saving advantage of the translation-loopapproach is embedded in the architecture.The SKY74138 features an integrated, fully programmable, fractional-N synthesizer suitable for EGPRS multi-slotoperation. The reference frequency for the synthesizer is suppliedby an integrated Voltage Controlled Crystal Oscillator (VCXO)circuit that enables the use of a low-cost crystal. The VCXO alsoprovides a buffered reference frequency output to supply otherdevices in the system.

The SKY74138 is packaged in a small, 40-pin 5 x 5 mm dual-rowRF Land Grid Array (RFLGA) package.

Please note: SKY74138-31 is being discontinued and is not recommended for new design.