The Next State-of-the-Art in Circuit Simulation

Transcription

1 The Next State-of-the-Art in Circuit Simulation Samuel Mertens, Mary Tolikas Ansoft Corporation

2 Requirements for the next state-of-the-art circuit simulator Consistency across analysis domains Model compatibility High capacity High speed Accuracy Robust convergence NEXXIM

3 Nexxim supports all required analyses Netlist or Schematic NEXXIM Simulation Engine Postprocessing DC Transient Harmonic Balance Single tone / Multi-tone AC AC / Time varying AC Noise DC / Time-varying Sweeps Variables ALL model parameters

4 Nexxim provides result consistency across domains All analyses, whether time-domain or frequencydomain, use the same models and simulate from the same netlist. * Gilbert cell mixer.subckt GilCellMix R R C uF C uF L nH C uF BJT BJTM5 area=1 BJT BJTM3 area=1 BJT BJTM3 area=1 BJT BJTM3 area=1.model BJTM1 NPN Bf= e2.ends GilCellMix X1 3 4 Vif 7 GilCellMix V_SRC R RVif Vif 0 50 R V_LO 5 0 sin( e9 0 0) V_RF1 2 break sin( e9 0 0) V_RF2 break 0 sin( e9 0 0).tran 0.01e-9 30e-9 0 3e-9.plot tran v(vif) *HB:HB2 MaxOrder=4 Freq[1]=2000 MHz Order[1]=15.end Frequency Domain Time Domain

5 Nexxim supports a variety of models Passives Resistors, Inductors, Capacitors Independent/Dependent Sources S-parameter elements (N-ports) Transmission Lines (W elements) Diodes JUNCAP Geometric Non-Geometric Fowler-Nordheim BJTs Gummel-Poon & extensions VBIC Philips MEXTRAM 503 / 504 HiCUM HBT MOSFETs Schichman Hodges BSIM3 BSIM4 Philips MOS 9 / MOS 11 SOI EPFL EKV HiSIM JFETs/MESFETs SPICE Curtice Statz Triquint IBIS models

6 Nexxim integrates with advanced EM and system tools HFSS 3D EM analysis DESIGNER Integrated Environment: Schematic Capture Layout / Planar EM System analysis NEXXIM Circuit Simulation

7 Nexxim achieves high capacity and speed 5 x 12 x BJT Mixer 25 transistors up to: 1023 harmonics 610,304 data pts. MOS Mixer up to: 1536 transistors 856,256 data pts.

8 Nexxim offers high accuracy at high speed Nexxim 7 x Competitor NCSU sqrt example 1188 BSIM3 transistors Transient analysis

9 Nexxim offers high capacity and speed Front-end for Bluetooth radio 2486 MOSFETs 13 BJTs 3-tone Harmonic Balance 24 minutes using Ansoft simulator

10 Nexxim offers robust convergence Frequency Divider Harmonic Balance Analysis Large number of harmonics required to capture square-wave output Nexxim converges in less than 1 min Competitor does not converge

11 Nexxim integrates with system level design vdd_psl_dff1_1 gnd_psl_dff1_1 V vdd_psl_dff1_1 vdd_andcml_1 vdd_preamp_1 W_ANDcml=8u A Ab U19 CML_AND B Bb b U1 presclr_dff R W_dff1=2u Rb D Db clk b clkb dff1_o1 R Rb D Db clk clkb ps_swalo2 U18 presclr_dff W_dff1=2u b V W_ANDcml=8u A Ab U2 CML_AND B Bb b R Rb D Db clk clkb U20 presclr_dff W_dff1=2u ps_swalo1 b + - V1281 DC=0 + - real_2p5v V1284 DC=0 + - V1288 DC=2.5 V1285 DC=0 PLL System Design For 1.8GHz GSM V V _ANDcml gnd_psl_dff1_1 gnd_andcml_1 gnd_preamp_1 clkb clk + - V1293 DC=0 + - V1294 DC=0 + - V1295 DC=0 V1277 DC=1 VO=1 VA=0.5 FRE=f_clk THETA=0 V1280 DC=1 VO=1 VA=0.5 FRE=f_clk THETA= V modsel_o out outb U17 Pre_Amplifier in inb out outb U29 Pre_Amplifier in inb 0 vdd_psl_dff1_1 to_asyn W_preamp_n=8u W_preamp_p=10u W_preamp_src=30u W_preamp_n=8u W_preamp_p=10u W_preamp_src=30u vdd_andcml_1 10k U25 CML_AND U26 CML_AND U27 CML_AND U28 CML_AND A W_ANDcml=8u A W_ANDcml=8u A W_ANDcml=8u A W_ANDcml=8u Ab Ab Ab Ab vdd_andcml_1 gnd_andcml_1 B Bb b B Bb b B Bb b _ANDcml B Bb b vdd_andcml_1 M183 nch L=0.5u W=8u M=1 0 gnd_andcml_1 U21 presclr_dff R W_dff1=2u Rb D Db clk b clkb asyn_o1 U22 presclr_dff R W_dff1=2u Rb D Db clk b clkb asyn_o2 U23 presclr_dff R W_dff1=2u Rb D Db clk b clkb asyn_o3 U24 presclr_dff R W_dff1=2u Rb D Db clk b clkb div64_65 div64_65b B=High, P=65 V B=Low, P=64 V _ANDcml M184 nch L=0.5u W=30u M=1 10k V V V 0 Starting Time + Bias Transient ~10.5ns

12 Nexxim offers high capacity without loss of accuracy SRAM cell 47,399 MOSFETs 62,000 devices Competitor does not provide the capacity Approximate Spice simulator does not provide the accuracy 422 seconds in Nexxim

13 Nexxim encapsulates technology advances in software engineering State-of-the-art software engineering C++ code from the ground up Templated C++ code for all analyses Automatic model compilation User-defined models just as fast as library models

14 Nexxim encapsulates technology advances in numerics Advanced Ansoft-proprietary numerics New variable timestep integration formula for Transient Analysis New preconditioners for Harmonic Balance New sparse matrix package that is faster than industry standard

15 Nexxim offers faster preconditioned Krylov methods for HB 10x These methods are industry standard for HB but are limited!

16 Nexxim advantages Higher capacity and speed for Harmonic Balance - Single tone - Particularly for multi-tone Robust convergence Unique transient analysis features - Improved error control - Novel integration techniques Consistency of results across domains - All analyses, whether time- or frequency-domain, use the same models and simulate from the same netlist Integration to EM tools