© CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Alp OGUZ 1,2, Dominique MORCHE 1, Catherine DEHOLLAIN 2, Erkan Nevzat ISA 1,2 1 CEA-Leti, MINATEC Campus, Grenoble, France 2 École Polytechnique Fédérale de Lausanne, Switzerland

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2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 3 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Problem Definition Wireless receivers Usually utilized in mobile applications Operate on batteries or energy scavenging structures Power dissipation is imposed by the requirements Higher requirements Higher power dissipation Over-specified receiver dissipates excessive power POWER IS STRICTLY LIMITED

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 4 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers A conventional receiver has a fixed configuration High specifications due to worst case conditions Dynamic range requirement alters during operation A function of signal and blocker conditions Receiver becomes over-specified Over-specified Receiver

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 5 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Over-specified Receiver – cont.d SOLUTION: Adaptive Power Reconfigurability High Freq. Processing Frequency Translation Low Freq. Processing Antenna Digital Processing Sensing & Reconfiguring Processed Signal Analog Blocks Digital Blocks

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 6 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Trade-off between LPF and ADC High order filter Low resolution ADC Low order filter High resolution ADC Should be optimized for minimum total power Results will indicate the dominant power consumer Requires high-level LPF and ADC power models Baseband Block Optimization SNDR Filter OrderSNDR

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 7 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Baseband Block Optimization – cont.d POWER MODELS Normalized real data points from the literature Up-to-date reconfigurable Active Gm-RC filter [Ozgun2006] Up-to-date SAR ADCs are used [Nuzzo2009, Harpe2010, C.Liu2010, W.Liu2010] Regions between the data points are extrapolated Constant capacitance scaling assumed while normalizing BW (implies P ~ BW)

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 8 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Baseband Block Optimization – cont.d Optimization is done for ZigBee receivers Filter power dominates Total power changes between 24 μW and mW Filter order changes between 0 and 3 Filter DR changes between dB and dB

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 9 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Average power dissipation depends on operating schedule Statistical data is hard to obtain An illustrative scenario is derived Blocker source at the center Signal power is constant Assumed P ~ Performance Evaluation The time weight of n th worst operating condition 1 R2R2 ω n = ω 1. (1.112) n-1

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 10 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Time weights calculated using the formula With adaptive power reconfigurability, P av = µW Without adaptive power reconfigurability, P av = mW Performance Evaluation – cont.d Power reduction by a factor of 36 (15.6 dB)

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 11 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Conclusions Investigated the effect of using adaptive power reconfigurability concept in wireless receivers Optimized the baseband block of a ZigBee receiver for minimum total power Filter should be reconfigurable, ADC not necessarily Illustrative scenario shows up to 36 times improvement is possible in average power dissipation

© CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers Innovation for industry Thanks for your attention…

2007 © CEA Tous droits réservés. Toute reproduction totale ou partielle sur quelque support que ce soit ou utilisation du contenu de ce document est interdite sans lautorisation écrite préalable du CEA All rights reserved. Any reproduction in whole or in part on any medium or use of the information contained herein is prohibited without the prior written consent of CEA 13 Adaptive Power Reconfigurability for Preventing Excessive Power Dissipation in Wireless Receivers References [Ozgun2006] M. T. Ozgun, Y. P. Tsividis, and G. Burra, Dynamic power optimization of active filters with application to zero IF receivers, IEEE J. Solid State Circuits, vol. 41, no. 6, pp , Jun [Nuzzo2009] P. Nuzzo et al., A 6 bit 50 MS/s threshold configuring SAR ADC in 90 nm digital CMOS, Symposium on VLSI Circuits, 2009, pp [Harpe2010] P. Harpe, C. Zhou, X. Wang, G. Dolmans, and H. de Groot, A 30fJ/conversion step 8b 0 to 10MS/s asynchronous SAR ADC in 90nm CMOS, Int. Solid State Circuits Conf. Digest of Technical Papers, Feb. 2010, pp [C.Liu2010] C. C. Liu et al., A 10b 100MS/s 1.13mW SAR ADC with binary scaled error compensation, Int. Solid State Circuits Conf. Digest of Technical Papers, Feb. 2010, pp [W.Liu2010] W. Liu, P. Huang, Y. Chiu, A 12b 22.5/45MS/s 3.0mW 0.059mm² CMOS SAR ADC achieving over 90dB SFDR, Int. Solid State Circuits Conf. Digest of Technical Papers, Feb. 2010, pp