A 3.2-mA 6-Bit Pipelined A/D Coverter for a Bluetooth RF Transceiver


IEICE TRANSACTIONS on Electronics   Vol.E85-C    No.8    pp.1538-1545
Publication Date: 2002/08/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on High-Performance Analog Integrated Circuits)
A/D converter,  CMOS,  low power,  pipeline,  Bluetooth,  

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A low-power-consumption 6-bit pipelined analog-to-digital converter for use in a BluetoothTM RF transceiver has been developed. The RF transceiver chip was fabricated using a 0.35-µm BiCMOS process, and the A/D converter is based on CMOS technology for digital logic. To reduce the power consumption of the converter, we used a look-ahead pipeline architecture to reduce the required settling time of an amplifier in the critical path of the converter. We show that through this reduction, amplifier power consumption of 600 µA can be reduced to 250 µA to achieve a 13-MHz conversion rate. We have also developed a low-power two-capacitor switched-capacitor common-mode feedback circuit which enables an offset cancellation of an amplifier during the reset phase. Offset cancellation is used in each stage of the S/H amplifier to reduce the overall offset of the converter. It achieves an effective number of bits of 5.7 at a conversion rate of 13 Msps and 5.0 at 26 Msps. The residual offset of the converter is only 4 mV. It has a low total current consumption of 3.2 mA at 13 Msps and a supply voltage of 2.8 V.