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PRELIMINARY
CYW43353
11. W LAN Radio Subsystem
The CYW43353 includes an integrated dual-band WLAN RF transceiver that has been optimized for use in 2.4 GHz and 5 GHz
Wireless LAN systems. It has been designed to provide low-power, low-cost, and robust communications for applications operating
in the globally available 2.4 GHz unlicensed ISM or 5 GHz U-NII bands. The transmit and receive sections include all on-chip filter-
ing, mixing, and gain control functions.
Ten RF control signals are available to drive external RF switches and support optional external power amplifiers and low-noise
amplifiers for each band. See the reference board schematics for further details.
A block diagram of the radio subsystem is shown in
Figure
28. Note that integrated on-chip baluns (not shown) convert the fully dif-
ferential transmit and receive paths to single-ended signal pins.
11.1 Receiver Path
The CYW43353 has a wide dynamic range, direct conversion receiver that employs high order on-chip channel filtering to ensure
reliable operation in the noisy 2.4 GHz ISM band or the entire 5 GHz U-NII band. An on-chip low-noise amplifier (LNA) in the 2.4
GHz path is shared between the Bluetooth and WLAN receivers, while the 5 GHz receive path has a dedicated on-chip LNA. Control
signals are available that can support the use of optional LNAs for each band, which can increase the receive sensitivity by several
dB.
11.2 Transmit Path
Baseband data is modulated and upconverted to the 2.4 GHz ISM or 5-GHz U-NII bands, respectively. Linear on-chip power amplifi-
ers are included, which are capable of delivering high output powers while meeting IEEE 802.11ac and IEEE 802.11a/b/g/n specifi-
cations without the need for external PAs. When using the internal PAs, closed-loop output power control is completely integrated.
As an option, external PAs can be used for even higher output power, in which case the closed-loop output power control is provided
by means of a-band and g-band TSSI inputs from external power detectors.
11.3 Calibration
The CYW43353 features dynamic and automatic on-chip calibration to continually compensate for temperature and process varia-
tions across components. These calibration routines are performed periodically in the course of normal radio operation. Examples of
some of the automatic calibration algorithms are baseband filter calibration for optimum transmit and receive performance, and
LOFT calibration for carrier leakage reduction. In addition, I/Q Calibration, R Calibration, and VCO Calibration are performed on-
chip. No per-board calibration is required in manufacturing test, which helps to minimize the test time and cost in large volume pro-
duction.
Document Number: 002-14949 Rev. *G
Page 54 of 113
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