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B.A. Bloechel

Bio: B.A. Bloechel is an academic researcher from Intel. The author has contributed to research in topics: Voltage regulator & Low-dropout regulator. The author has an hindex of 4, co-authored 4 publications receiving 707 citations.

Papers
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Journal ArticleDOI
Peter Hazucha1, Tanay Karnik1, B.A. Bloechel1, C. Parsons1, D. Finan1, Shekhar Borkar1 
TL;DR: In this article, the authors demonstrate a fully integrated linear regulator for multisupply voltage microprocessors implemented in a 90 nm CMOS technology, which enables a 90 mV/sub P-P/output droop with only a small on-chip decoupling capacitor of 0.6 nF.
Abstract: We demonstrate a fully integrated linear regulator for multisupply voltage microprocessors implemented in a 90 nm CMOS technology. Ultra-fast single-stage load regulation achieves a 0.54-ns response time at 94% current efficiency. For a 1.2-V input voltage and 0.9-V output voltage the regulator enables a 90 mV/sub P-P/ output droop for a 100-mA load step with only a small on-chip decoupling capacitor of 0.6 nF. By using a PMOS pull-up transistor in the output stage we achieved a small regulator area of 0.008 mm/sup 2/ and a minimum dropout voltage of 0.2 V for 100 mA of output current. The area for the 0.6-nF MOS capacitor is 0.090 mm/sup 2/.

509 citations

Proceedings ArticleDOI
Ali Keshavarzi1, S. Ma1, Siva G. Narendra1, B.A. Bloechel1, Kaizad Mistry1, Tahir Ghani1, S. Borkar1, Vivek De1 
06 Aug 2001
TL;DR: It is shown that RBB becomes less effective for leakage reduction at shorter channel lengths and lower V/sub t/ at both high and room temperatures, especially when target intrinsic leakage currents are high.
Abstract: Examines the effectiveness of opportunistic use of reverse body bias (RBB) to reduce leakage power during active operation, burn-in, and standby in 0.18 /spl mu/m single-V/sub t/ and 0.13 /spl mu/m dual-V/sub t/ logic process technologies. Investigates its dependencies on channel length, target V/sub t/, temperature and technology generation. Shows that RBB becomes less effective for leakage reduction at shorter channel lengths and lower V/sub t/ at both high and room temperatures, especially when target intrinsic leakage currents are high. RBB effectiveness also diminishes with technology scaling primarily because of worsening short-channel effects (SCE), particularly when target V/sub t/ values are low. A model is given that relates different transistor leakage components to full-chip leakage current, and is validated through test-chip measurements across a range of RBB values.

181 citations

Journal ArticleDOI
TL;DR: A 32 b integer execution core implements 12 instructions and circuit and body bias techniques together increase the core clock frequency to 5 GHz, in a 130 nm six-metal dual-V/sub T/ CMOS process.
Abstract: A 32-bit integer execution core containing a Han-Carlson arithmetic-logic unit (ALU), an 8-entry /spl times/ 2 ALU instruction scheduler loop and a 32-entry /spl times/ 32-bit register file is described. In a 130 nm six-metal, dual-V/sub T/ CMOS technology, the 2.3 mm/sup 2/ prototype contains 160 K transistors. Measurements demonstrate capability for 5-GHz single-cycle integer execution at 25/spl deg/C. The single-ended, leakage-tolerant dynamic scheme used in the ALU and scheduler enables up to 9-wide ORs with 23% critical path speed improvement and 40% active leakage power reduction when compared to a conventional Kogge-Stone implementation. On-chip body-bias circuits provide additional performance improvement or leakage tolerance. Stack node preconditioning improves ALU performance by 10%. At 5 GHz, ALU power is 95 mW at 0.95 V and the register file consumes 172 mW at 1.37 V. The ALU performance is scalable to 6.5 GHz at 1.1 V and to 10 GHz at 1.7 V, 25/spl deg/C.

32 citations

Proceedings Article
01 Jan 2005
TL;DR: In this paper, the authors demonstrate a fully integrated linear regulator for multisupply voltage microprocessors implemented in a 90 nm CMOS technology, which enables a 90 mVp-p output droop for a 100mA load step with only a small on-chip decoupling capacitor of 0.6 nF.
Abstract: We demonstrate a fully integrated linear regulator for multisupply voltage microprocessors implemented in a 90 nm CMOS technology. Ultra-fast single-stage load regulation achieves a 0.54-ns response time at 94% current efficiency. For a 1.2-V input voltage and 0.9-V output voltage the regulator enables a 90 mVp-p output droop for a 100-mA load step with only a small on-chip decoupling capacitor of 0.6 nF. By using a PMOS pull-up transistor in the output stage we achieved a small regulator area of 0.008 mm 2 and a minimum dropout voltage of 0.2 V for 100 mA of output current. The area for the 0.6-nF MOS capacitor is 0.090 mm 2 .

24 citations


Cited by
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Proceedings ArticleDOI
Shekhar Borkar1, Tanay Karnik1, Siva G. Narendra1, James W. Tschanz1, Ali Keshavarzi1, Vivek De1 
02 Jun 2003
TL;DR: Process, voltage and temperature variations; and their impact on circuit and microarchitecture; and possible solutions to reduce the impact of parameter variations and to achieve higher frequency bins are presented.
Abstract: Parameter variation in scaled technologies beyond 90nm will pose a major challenge for design of future high performance microprocessors. In this paper, we discuss process, voltage and temperature variations; and their impact on circuit and microarchitecture. Possible solutions to reduce the impact of parameter variations and to achieve higher frequency bins are also presented.

1,503 citations

Proceedings ArticleDOI
24 Oct 2008
TL;DR: It is concluded that on-chip regulators can significantly improve DVFS effectiveness and lead to overall system energy savings in a CMP, but architects must carefully account for overheads and costs when designing next-generation DVFS systems and algorithms.
Abstract: Portable, embedded systems place ever-increasing demands on high-performance, low-power microprocessor design. Dynamic voltage and frequency scaling (DVFS) is a well-known technique to reduce energy in digital systems, but the effectiveness of DVFS is hampered by slow voltage transitions that occur on the order of tens of microseconds. In addition, the recent trend towards chip-multiprocessors (CMP) executing multi-threaded workloads with heterogeneous behavior motivates the need for per-core DVFS control mechanisms. Voltage regulators that are integrated onto the same chip as the microprocessor core provide the benefit of both nanosecond-scale voltage switching and per-core voltage control. We show that these characteristics provide significant energy-saving opportunities compared to traditional off-chip regulators. However, the implementation of on-chip regulators presents many challenges including regulator efficiency and output voltage transient characteristics, which are significantly impacted by the system-level application of the regulator. In this paper, we describe and model these costs, and perform a comprehensive analysis of a CMP system with on-chip integrated regulators. We conclude that on-chip regulators can significantly improve DVFS effectiveness and lead to overall system energy savings in a CMP, but architects must carefully account for overheads and costs when designing next-generation DVFS systems and algorithms.

758 citations

Journal ArticleDOI
07 Aug 2002
TL;DR: Bidirectional adaptive body bias (ABB) is used to compensate for die-to-die parameter variations by applying an optimum pMOS and nMOS body bias voltage to each die which maximizes the die frequency subject to a power constraint as mentioned in this paper.
Abstract: Bidirectional adaptive body bias (ABB) is used to compensate for die-to-die parameter variations by applying an optimum pMOS and nMOS body bias voltage to each die which maximizes the die frequency subject to a power constraint. Measurements on a 150 nm CMOS test chip which incorporates on-chip ABB, show that ABB reduces variation in die frequency by a factor of seven, while improving the die acceptance rate. An enhancement of this technique, that compensates for within-die parameter variations as well, increases the number of dies accepted in the highest frequency bin. ABB is therefore shown to provide bin split improvement in the presence of increasing process parameter variations.

740 citations

01 Jan 2002
TL;DR: Measurements on a 150 nm CMOS test chip show that on-chip bidirectional adaptive body biasing compensates effectively for die-to-die parameter variation to meet both frequency and leakage requirements.
Abstract: Measurements on a 150 nm CMOS test chip show that on-chip bidirectional adaptive body biasing compensates effectively for die-to-die parameter variation to meet both frequency and leakage requirements. An enhancement of this technique to correct for within-die variations triples the accepted die count in the highest frequency bin.

736 citations

Proceedings ArticleDOI
10 Nov 2002
TL;DR: In this paper, the authors show how the simultaneous use of adaptive body biasing (ABB) and dynamic voltage scaling (DVS) can be used to reduce power in high-performance processors.
Abstract: Dynamic voltage scaling (DVS) reduces the power consumption of processors when peak performance is unnecessary. However, the achievable power savings by DVS alone is becoming limited as leakage power increases. In this paper, we show how the simultaneous use of adaptive body biasing (ABB) and DVS can be used to reduce power in high-performance processors. Analytical models of the leakage current, dynamic power, and frequency as functions of supply voltage and body bias are derived and verified with SPICE simulation. We then show how to determine the correct trade-off between supply voltage and body bias for a given clock frequency and duration of operation. The usefulness of our approach is evaluated on real workloads obtained using real-time monitoring of processor utilization for four applications. The results demonstrate that application of simultaneous DVS and ABB results in an average energy reduction of 48% over DVS alone.

497 citations