PRELIMINARY
CYW20710
2. Integrated Radio Transceiver
The CYW20710 has an integrated radio transceiver that has been optimized for use in 2.4 GHz Bluetooth wireless systems. It has
been designed to provide low-power, low-cost, robust communications for applications operating in the globally available 2.4 GHz
unlicensed ISM band. The CYW20710 is fully compliant with the Bluetooth Radio Specification and enhanced data rate specification
and meets or exceeds the requirements to provide the highest communication link quality of service.
2.1 Transmitter Path
The CYW20710 features a fully integrated zero IF transmitter. The baseband transmitted data is digitally modulated in the modem
block and up-converted to the 2.4 GHz ISM band in the transmitter path. The transmitter path consists of signal filtering, I/Q up-
conversion, a high-output power amplifier (PA), and RF filtering.
The CYW20710 also incorporates modulation schemes to support enhanced data rates.
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P/4-DQPSK for 2 Mbps
8-DPSK for 3 Mbps
2.1.1 Digital Modulator
The digital modulator performs the data modulation and filtering required for the GFSK, /4DQPSK, and 8-DPSK signals. The fully
digital modulator minimizes any frequency drift or anomalies in the modulation characteristics of the transmitted signal and is much
more stable than direct VCO modulation schemes.
2.1.2 Power Amplifier
The CYW20710 has an integrated PA that can be configured for Class 2 operation, transmitting up to +4 dBm. The PA can also be
configured for Class 1 operation, transmitting up +10 dBm at the chip in gFSK mode, when a minimum supply voltage of 2.5V is applied
to VDDTF.
Because of the linear nature of the PA, combined with integrated filtering, minimal external filtering is required to meet Bluetooth and
regulatory harmonic and spurious requirements.
Using a highly linearized, temperature compensated design, the PA can transmit +10 dBm for basic rate and +8 dBm for enhanced
data rates (2 to 3 Mbps). A flexible supply voltage range allows the PA to operate from 1.2V to 3.3V. A minimum supply voltage of
2.5V is required at VDDTF to achieve +10 dBm of transmit power.
2.2 Receiver Path
The receiver path uses a low IF scheme to downconvert the received signal for demodulation in the digital demodulator and bit
synchronizer. The receiver path provides a high degree of linearity, an extended dynamic range, and high order on-chip channel
filtering to ensure reliable operation in the noisy 2.4 GHz ISM band. The front-end topology, with built-in out-of-band attenuation,
enables the device to be used in most applications without off-chip filtering. For integrated handset operation where the Bluetooth
function is integrated close to the cellular transmitter, minimal external filtering is required to eliminate the desensitization of the
receiver by the cellular transmit signal.
2.2.1 Digital Demodulator and Bit Synchronizer
The digital demodulator and bit synchronizer uses the low IF received signal to perform an optimal frequency tracking and bit synchro-
nization algorithm.
2.2.2 Receiver Signal Strength Indicator
The CYW20710 radio provides a Receiver Signal Strength Indicator (RSSI) signal to the baseband so that the controller can take part
in a Bluetooth power-controlled link by providing a metric of its own receiver signal strength to determine whether the transmitter
should increase or decrease its output power.
2.3 Local Oscillator Generation
Local Oscillator (LO) generation provides fast frequency hopping (1600 hops/second) across the 79 maximum available channels.
The LO generation subblock employs an architecture for high immunity to LO pulling during PA operation. The device uses fully-
integrated PLL loop filters.
Document No. 002-14804 Rev. *H
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CYPRESS [ CYPRESS ]
