ADVANCE
CYW43570
11. WLAN Radio Subsystem
The CYW43570 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 filtering,
mixing, and gain control functions.
Sixteen RF control signals are available (eight per core) 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.
11.1 Receiver Path
The CYW43570 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. Control signals are available that can support the
use of optional LNAs for each band, which can increase the receive sensitivity by several decibels.
11.2 Transmitter Path
Baseband data is modulated and upconverted to the 2.4 GHz ISM or 5-GHz U-NII bands, respectively. Linear on-chip power amplifiers
are included, which are capable of delivering high output powers while meeting IEEE 802.11ac and IEEE 802.11a/b/g/n specifications
without the need for external PAs. When using the internal PAs, closed-loop output power control is completely integrated.
11.3 Calibration
The CYW43570 features dynamic and automatic on-chip calibration to continually compensate for temperature and process variations
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 production.
Document Number: 002-15054 Rev. *I
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