BCM4330 Preliminary Data Sheet
Bluetooth Radio
Receiver
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 BCM4330 to be used in most applications
with no 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.
Digital Demodulator and Bit Synchronizer
The digital demodulator and bit synchronizer take the low-IF received signal and perform an optimal frequency
tracking and bit synchronization algorithm.
Receiver Signal Strength Indicator
The radio portion of the BCM4330 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.
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 BCM4330 uses an internal RF and IF loop filter.
Calibration
The BCM4330 radio transceiver features an automated calibration scheme that is fully self contained in the
radio. No user interaction is required during normal operation or during manufacturing to provide the optimal
performance. Calibration optimizes the performance of all the major blocks within the radio to optimal
conditions, including gain and phase characteristics of filters, matching between key components, and key gain
blocks. This takes into account process variation and temperature variation. Calibration occurs transparently
during normal operation during the settling time of the hops and calibrates for temperature variations as the
device cools and heats during normal operation in its environment.
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BROADCOM
BCM4330 Preliminary Data Sheet
April 28, 2011 • 4330-DS304-RI
Page 41
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