Post on 06-Jan-2018
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Course: High-Speed and Course: High-Speed and Low-Power VLSI (97.575)Low-Power VLSI (97.575)
Professor: Professor: Maitham Maitham ShamsShams
PresentationPresentation: : True True Single-Phase Adiabatic Single-Phase Adiabatic
CircuitryCircuitryBy By
Ehssan HosseinzadehEhssan HosseinzadehSpecial StudentSpecial Student
OutlineOutline
IntroductionAdiabatic – Switching CircuitsTrue Single-Phase adiabatic CircuitResultsConclusionReferences
IntroductionIntroduction
Importance of Reducing Power DissipationTechniques
=>Parallelism => Pipeline=> Transformation=> Reduce the Chip wide Supply
voltage=> Energy Recovery
Conventional Energetic
Swinging voltage on capacitor:- Zero => V-V => ZeroEngergy dissipation per transition E= ½ CV2
Adiabatic - Switching Circuits
Recovery Energy
Adiabatic - Switching Circuits
Ediss= P. T = I2 . R .T
= (RC/T) CV2
True Single-Phase adiabatic Circuit
Different Approaches: Signal voltage swing > Vt of CMOS
=> Adiabatic AmplificationDynamic logic families=> 2N2P, 2N-2N2P,
=> True Signle-Phase Energy-Recovery Logic (TSEL) => Source–Coupled Adiabatic Logic (SCAL)
True Single-Phase Energy-Recovery Logic (TSEL)
Cascades are composed of alternating PMOS and NMOS gatesTSEL GATES
True Single-Phase adiabatic Circuit
PMOS DP:Vpc: H-LVpc VRP - |vtp|
EP:•Vin: H , Vpc:L•Vpc < VRP - |vtp|•Ddp > |Vtp| •Vpc VRP - |vtp|
NMOSEN:•Vpc > VRN + |vtn|
CN:•Vpc VRN + |vtn|
TSEL CascadesTSEL Cascades
TSEL Cascades are built by stringing together alternating PMOS and NMOS gates
SCAL GatesSCAL Gates
Single Phase power Clock Operation
Tunable Current Source at each Gate
Vpc
Vbp
Vbn
DP:Vpc: H-LAdiabatlically tillVpc > |Vtp|EP:Vpc: L-HVbp increaseVdd - |Vbp| > |Vtp|Vpc < Vxp - |Vtp|Dpp > |Vtp|Vpc > Vxp - |Vtp|
SCAL CascadesSCAL Cascades
ResultsResults
8-bit Carry-Lookahead adder (CLAs)Developed in Static CMOS, PAL, 2N2P, TSEL, SCAL (0.5um)
Freq: 10 –200 MHzSCAL CLA => 1.5 – 2.5 times more
efficient than PAL, 2N2PSCAL CLA => 2 – 5 times less dissipative
than purely combinational or pipelined CMOS
ConclusionConclusion
True Single-phase adiabatic logic family:TSEL, SCALSource-coupled variant of TSEL => Increase energy efficiency by using tunable current source Avoid the problems:
Multiple Power-clock schemes- Increased energy dissipation- Layout Complexity in clock distribution,- Clock Skew- Multiple power–clock generator
ReferencesReferences
True Single Phase Adiabatic Circuitry, Suhwan Kim and Mario PapaefthymiouEnergy Recovery For Low Power CMOS, WC Athas and N. TzartanisLow Power Digital Systems Based on Adiabatic-Switching Principles, William C. Athas