SKY74067-21 Datasheet, PDF (3/10 Pages) Skyworks Solutions Inc. – Dual-Band CDMA2000 Transmitter for Cellular CDMA and PCS Femtocell Applications

DATA SHEET • SKY74067-21 CDMA2000 TRANSMITTER
Technical Description
Baseband Filter
In voltage mode operation, the baseband section of the
SKY74067-21 contains a simple RC filter to reject receive band
noise from incoming I and Q signals.
VCO, LO Chain, and PLL
The VCO has an internal tank circuit automatically tuned to the
desired frequency. The VCO is connected to an on-chip PLL and
LO generation blocks. The output of the LO generation blocks
drives the LO port of the I/Q RF upconverter.
A dual-mode fractional-N/integer-N PLL is used to lock the VCO to
the desired frequency in cellular mode. A bi-directional buffer is
available to measure the VCO output or to enable use of an
external LO for testing purposes.
I/Q RF Upconverter
The I/Q RF upconverter converts the incoming I/Q signal to the
desired RF output signal. The upconverter passes the output
signal directly to the variable gain PA drivers. The LO for the
upconverter is provided by the VCO and LO generation blocks.
The upconverter block consists of two separate mixers, one for
cellular mode operation and the other for PCS mode. The output
of the PCS mixer is routed to the PCS PA driver and the cellular
mixer output is routed to the cellular PA driver.
Variable Gain PA Drivers
The SKY74067-21 includes two PA drivers. These drivers control
the power level of the signal provided by the PCS and cellular
upconverters. The gain of both drivers is variable, yielding over
75 dB of dynamic range.
The PCS driver output is single-ended, while the cellular driver is
differential. Both are open collector outputs that require external
matching.
Serial Bus Interface
A three-wire serial bus with read/write capability provides mode
and bias control, and control of the PLL. The serial interface
consists of three signals: a bus clock (CLK), a bus enable
(LATCH_ENABLE), and the serial, bi-directional data line (DATA).
Package and Handling Information
Since the device package is sensitive to moisture absorption, it is
baked and vacuum packed before shipping. Instructions on the
shipping container label regarding exposure to moisture after the
container seal is broken must be followed. Otherwise, problems
related to moisture absorption may occur when the part is
subjected to high temperature during solder assembly.
The SKY74067-21 is rated to Moisture Sensitivity Level 3 (MSL3)
at 260 °C. It can be used for lead or lead-free soldering. For
additional information, refer to the Skyworks Application Note,
PCB Design & SMT Assembly/Rework Guidelines for RFLGA
Packages, document number 103147.
Care must be taken when attaching this product, whether it is
done manually or in a production solder reflow environment.
Production quantities of this product are shipped in a standard
tape and reel format. For packaging details, refer to the Skyworks
Application Note Tape and Reel, document number 101568.
Electrical and Mechanical Specifications
Signal pin assignments and functional pin descriptions are
described in Table 1. The absolute maximum ratings of the
SKY74067-21 are provided in Table 2. The recommended
operating conditions are specified in Table 3 and electrical
specifications are provided in Table 4.
An application schematic diagram for the SKY74067-21 is shown
in Figure 3. The package dimensions for the 32-pin RFLGA are
shown in Figure 4, and the tape and reel dimensions are provided
in Figure 5.
Electrostatic Discharge (ESD) Sensitivity
The SKY74067-21 is a static-sensitive electronic device. Do not
operate or store near strong electrostatic fields. Take proper ESD
precautions.
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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