LG RBFS C921A Users manual

Description of Functional Blocks

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RBFS

C921A BT Ass’’

C921A BT Ass

Rev A,

y Module

Feb

2009

RBFS-C921A-AN-01-A

LG Innotek

Hanyang Univ. 1271, Sa-dong, Sangrok-gu ,

Ansan-si, Gyeonggi-do 426-791, Korea

Tel:82-31-436-7653 Fax:82-31-436-7991 www.lginnotek.com

COMMERCIAL IN CONFIDENCE

All specification are preliminary and LG Innotek reserves the r i ght to change these without notice.

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1. RF Receiver Block

1.1 RF Receiver

The receiver features a near-zero Intermediate Frequency (IF) architecture that allows the channel filters to be integrated onto 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 WLCSP to exceed the Bluetooth requirements for cochannel and adjacent channel rejection. For EDR, an ADC is used to digitise the IF received signal.

1.1.1 Low Noise Amplifier

The LNA can be configured to operate in single-ended or differential mode. Singleended mode is used for Class 1 Bluetooth operation; differential mode is used for Class 2 operation.

C921A

1.1.2 Analogue to Digital Converter

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.

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2. RF Transmitter Block

2.1 IQ Modulator

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.

2.2 Power Amplifier

The internal Power Amplifier (PA) has a maximum output power of +6dBm. This allows Bluetooth Main Chipset 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. But Our Module support Class2 type

2.3 Auxiliary DAC

C921A

An 8-bit voltage Auxiliary DAC is provided for power control of an external PA for Class 1 operation or any other customer specific application.

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