PT8R1002 Datasheet, PDF(5/26 Page) List of Unclassifed Manufacturers – CMOS Zero-IF Radio Transceiver IC for Bluetooth

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Preliminary Data Sheet

PT8R1002 CMOS Zero-IF

Radio Transceiver IC for Bluetooth

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The AGC and filter are optimally designed to meet both the

stringent requirements of gain setting and Adjacent Channel

Selectivity (ACS) in Bluetooth. In ISM frequency band appli-

cations, excellent adjacent channel selectivity is required,

because there can be too many blockers operating simulta-

neously. Thus, both channel filter and AGC circuits must have

high linearity and low noise performance. The first channel

filter and first AGC used have IIP3 greater than 30dBm. The

remaining channel filters and AGCâ s are optimized to obtain

high ACS.

RF transmitter

The transmitter is composed of a dual DAC for the I/Q signal

paths, channel filter, Baseband-to-RF up- conversion Mixer,

and power amplifier with 2 dBm output power. The phase locked

loop frequency synthesizer is shared with RF receiver to mini-

mize the hardware components. The transmitter features a di-

rect up-conversion scheme to minimize the frequency drift

during a transmit timeslot and also results in a well-controlled

modulation index. The baseband channel filter offers excel-

lent out-of-band suppression and equalized signals to mini-

mize the interference with the on-chip receiver. With the nomi-

nal transmit power of 0 dBm, the transmitter can be used in

class 2 and class 3 radios, and can be simply implemented in

class 1 with an external RF power amplifier.

PLL

The radio synthesizer is fully integrated and thus does not

require any external elements. It is designed with PTIâ s propri-

etary frequency synthesizer technologies, which minimize

phase noise and coupling to the RF amplifiers. An on-chip

reference oscillator is provided and requires an external crys-

tal or a reference clock. The external crystal (reference clock)

frequency should be 13MHz or 16MHz with 20 ppm accuracy.

PT8R1002 supports the BlueRFâ¢ RXMODE2 Bluetooth inter-

face with both unidirectional and JTAG serial interface or bidi-

rectional and DBUS serial interface which are all compatible

with the PTI PT8R1202 Bluetooth Baseband controller. In this

mode, external Bluetooth baseband delivers the SYNCWORD

detection indication to PT8R1002 when it detects a Bluetooth

SYNCWORD in received data.

I/O Description

RF interface

The radio interface establishes the connection of antenna-to-

LNA in receiving mode and antenna-to-power amplifier in

transmitting mode. The actual configuration of RF front-end

can be seen Figure 1. An antenna filter is located between the

antenna and SPDT (Single Pole Double Throw) switch. The

antenna filter blocks unwanted signals in receive mode and

suppresses harmonics in the transmit mode. The filter can be

either a discrete component or fully integrated in ceramic sub-

strate. The SPDT switch isolates the transmit path and the re-

ceive path and thus impedance can be matched for entire sig-

nal path. A matching circuit is placed between LNA_IN pin

and SPDT switch to match the 50 ohm source to the complex

input impedance of the LNA. Another external matching cir-

cuit is required at PA_OUT to transfer maximum power to the

antenna.

BlueRF RXMODE2 baseband interface

PT8R1002 supports the BlueRFâ¢ RXMODE2 Bluetooth ra-

dio interface with unidirectional and JTAG serial program-

ming interfaces or bidirectional and DBUS serial program-

ming interface, which are compatible with the PTI PT12002

Bluetooth baseband controller. In RXMODE2, the

SYNCWORD correlator is located in baseband controller, and

it detects signal feeds into PT8R1002.

Baseband modem

Unidirectional interface

The baseband GFSK modem is implemented in a compact dedi-

cated logic that provides excellent performance in the pres-

ence of noise, interferers, and frequency offset/drift, while con-

suming very small power. The baseband modem interface is

designed to transfer Bluetooth data between PT8R1002 and a

baseband controller. The GFSK demodulator performs fre-

quency demodulation. The inherent frequency offset compen-

sation block can guarantee stable operation in the present of

large frequency deviation, which is activated with

SYNCDETECT asserted. The GFSK modulator provides a pre-

cise modulation index control and a Gaussian spectral shap-

ing.

The interface connections for unidirectional mode are shown

in Figure 4.

PT0124(12/04)

Ver:2

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