SKY74067-21 Datasheet, PDF (1/10 Pages) Skyworks Solutions Inc. – Dual-Band CDMA2000 Transmitter for Cellular CDMA and PCS Femtocell Applications

DATA SHEET
SKY74067-21: Dual-Band CDMA2000 Transmitter for Cellular
CDMA and PCS Femtocell Applications
Applications
• Cellular CDMA and PCS femto/pico cell base stations
• Cellular CDMA and PCS repeaters
Features
• Low power consumption in all operating modes
• Direct upconversion architecture
• Device controlled using a three-wire read/write serial bus
interface with independent supply voltage
• Baseband RC filter to reject receive band noise
• Fully integrated VCO with auto-tuning
• Dual-mode fractional-N/integer-N PLL
• Variable gain PA drivers
• Differential cellular driver output matched to 200 Ω
• Single-ended PCS driver output matched to 50 Ω
• Transmit power control with >75 dB dynamic range
• Low current consumption at low transmit power minimizes
current consumption and noise
• Hardware TX_ENABLE for gated mode operation
• RFLGA™ (32-pin, 5 x 5 x 1 mm) Pb-free (MSL3, 260 °C per
JEDEC J-STD-020) package with downset paddle
Skyworks offers lead (Pb)-free, RoHS (Restriction of
Hazardous Substances) compliant packaging.
Description
The SKY74067-21 transmitter is a highly integrated device for
dual-band Code Division Multiple Access (CDMA) femtocell base
station applications. The SKY74067-21 supports femtocells in the
cellular CDMA and Personal Communications System (PCS)
bands.
The device requires a minimum number of external components
to complete a CDMA2000 radio subsystem. Included on-chip are
the baseband filter, direct upconversion In-Phase and Quadrature
(I/Q) mixers, variable gain power amplifier (PA) drivers, a fully
integrated Voltage Controlled Oscillator (VCO) with Local Oscillator
(LO) generation blocks, and a dual-mode fractional-N/integer-N
Phase Locked Loop (PLL).
External components needed for operation include bias resistors,
bypass capacitors, and passives to comprise the PLL loop filter.
The signal enters the chip as an analog baseband In-Phase and
Quadrature (I/Q) signal. It is filtered by the baseband filter and
upconverted to the desired RF transmit frequency. The signal is
amplified by one of two upconverters, depending on whether the
chip is operating in cellular or PCS mode. The resulting signal is
fed through the appropriate PA driver stage to provide variable
output power and to drive the external PA. The signal is then
filtered by an external Surface Acoustic Wave (SAW) filter and
sent to the PA to obtain the final rated power.
The 32-pin RF Land Grid Array (RFLGA) device package and
pinout are shown in Figure 1. Figure 2 shows a functional block
diagram for the SKY74067-21.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
200803A • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • April 13, 2009
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