BC41B143A-ANN-E4 ETC, BC41B143A-ANN-E4 Datasheet - Page 39

• Manufacturer Part Number: BC41B143A-ANN-E4
• Description: Bluecore 4-rom CSP EDR Single Chip Bluetooth v2.0 + EDR System
• Manufacturer: ETC

8
8.1
The receiver features a near-zero Intermediate Frequency (IF) architecture that allows the channel filters to be
integrated on to the die. Sufficient out-of-band blocking specification at the Low Noise Amplifier (LNA) input
allows the radio to be used in close proximity to Global System for Mobile Communications (GSM) and Wideband
Code Division Multiple Access (W-CDMA) cellular phone transmitters without being desensitised. The use of a
digital Frequency Shift Keying (FSK) discriminator means that no discriminator tank is needed and its excellent
performance in the presence of noise allows BlueCore4-ROM CSP to exceed the Bluetooth requirements for
co-channel and adjacent channel rejection.
For EDR, an Analogue to Digital Converter (ADC) is used to digitise the IF received signal.
8.1.1
The LNA can be configured to operate in single-ended or differential mode. Single-ended mode is used for
Class 1 Bluetooth operation. Differential mode is used for Class 2 operation.
8.1.2
The Analogue to Digital Converter (ADC) is used to implement fast Automatic Gain Control (AGC). The ADC
samples the Received Signal Strength Indicator (RSSI) voltage on a slot-by-slot basis. The front-end LNA gain is
changed according to the measured RSSI value, keeping the first mixer input signal within a limited range. This
improves the dynamic range of the receiver, improving performance in interference limited environments.
8.2
8.2.1
The transmitter features a direct IQ modulator to minimise the frequency drift during a transmit timeslot, which
results in a controlled modulation index. Digital baseband transmit circuitry provides the required spectral
shaping.
8.2.2
The internal Power Amplifier (PA) has a maximum output power of +6dBm allowing BlueCore4-ROM CSP to be
used in Class 2 and Class 3 radios without an external RF PA. Support for transmit power control allows a simple
implementation for Class 1 with an external RF PA.
8.2.3
An 8-bit voltage Auxiliary DAC is provided for power control of an external PA for Class 1 operation or for any
other customer specific application.
8.3
The radio synthesiser is fully integrated onto the die with no requirement for an external Voltage Controlled
Oscillator (VCO) screening can, varactor tuning diodes, LC resonators or loop filter. The synthesiser is
guaranteed to lock in sufficient time across the guaranteed temperature range to meet the Bluetooth Specification
v2.0 + EDR.
8.4
BlueCore4-ROM CSP contains one linear 1.8V regulator which may be used to power the 1.8V supplies of the
device.
BC41B143A-ds-002Pd
Description of Functional Blocks
RF Receiver
Low Noise Amplifier
Analogue to Digital Converter
RF Transmitter
IQ Modulator
Power Amplifier
Auxiliary DAC
RF Synthesiser
Power Control and Regulation
This material is subject to CSR’s non-disclosure agreement
© Cambridge Silicon Radio Limited 2005
Production Information
Description of Functional Blocks
Page 39 of 89