CYWUSB6941 datasheet(3/14 Pages) CYPRESS

3 / 14 page

PRELIMINARY

CYWUSB6941

Document #: 38-16004 Rev. *A

Page 3 of 14

3.0

Functional Overview

The Cypress CYWUSB6941 WirelessUSB EX transceiver is designed to work with the Cypress CYWUSB6942 WirelessUSB EX

baseband controller to provide a complete WirelessUSB EX solution. The CYWUSB6941 contains a 2.4-GHz radio transceiver,

a GFSK modem, and a radio control interface that communicates with the CYWUSB6942 WirelessUSB EX baseband. The

CYWUSB6941 also facilitates the development of a complete WirelessUSB EX system with a minimum number of additional

components, typically requiring only eight external components (including crystal) for ease of implementation and manufacturing

(refer to Figure 3-1). Specific features include:

• 2.4-GHz frequency-hopping spread spectrum (FHSS) transceiver

• GFSK modulator/demodulator

• No external transmit/receive switch required

• Minimizes the need for external components

• Closed-loop phase-locked loop (PLL)

• VCO is integrated in the CYWUSB6941

• No external loop circuitry required

• Radio control interface.

3.1

2.4-GHz Radio Transceiver and GFSK Modem

The receiver is a low-IF architecture with fully integrated IF filters to achieve high performance in the presence of interference.

The FM demodulator and fast data slicer are fully integrated.

The hop frequency synthesizer provides the frequency-hopping local oscillator for the transmitter and receiver. The only external

components required are reference crystal, and several capacitors. The RF VCO is fully integrated, requiring no external tank

circuits.

The transmitter uses a DSP-based vector modulator to convert the transmit data to an accurate GFSK-modulated carrier. There

are a variety of DC power control features for transmitter, synthesizer, and receiver functions to optimize the average current drain.

3.2

Clocking

The CYWUSB6941 requires an external 13-MHz crystal with the following characteristics:

• Crystal temperature stability:

± 15 ppm max

• Crystal load capacitance: 10 – 15 pF.

The crystal has to be placed across the X13IN and X13 pins. No extra capacitors are needed.

CYWUSB6941 Datasheet(PDF) 3 Page - Cypress Semiconductor