Automated parameter conversion from HICUM/L2 to HICUM/L0

Transcription

1 Automated parameter conversion from HICUM/L2 to HICUM/L Automated parameter conversion from HICUM/L2 to HICUM/L A. Pawlak 1, M. Schröter 1,2, A. Mukherjee 1, S. Lehmann 1 1 Chair for Electron Devices and Integr. Circuits, Univ. of Technol. Dresden, Germany 2 ECE Dept., University of California San Diego, La Jolla, CA, USA [email protected], [email protected] HICUM Workshop, Bordeaux, June 211 AP, MS 1

2 Automated parameter conversion from HICUM/L2 to HICUM/L Outline Outline Introduction Basic procedure MATLAB interface Application to experimental data HICUM/L limitations Summary AP, MS 2

3 Automated parameter conversion from HICUM/L2 to HICUM/L Introduction Introduction Simplified model HICUM/L allows significant reduction of simulation time in large circuits Simulation time [%] DC built-in model Simulation time [%] AC L2 v2.3 L v1.2 L v1.3 L v1.2 L2 v2.3 L v1.2 L v1.3 L v1.2 (VerilogA compiled code was used for these three models Parameter extraction is different since model formulation differs Extraction for HICUM/L2 provides complete set of geometry scalable parameters => Direct parameter conversion from L2 to L obviates need for separate extraction AP, MS 3

4 Automated parameter conversion from HICUM/L2 to HICUM/L Basic procedure Basic procedure Most parameters can be directly converted, e.g.: c 1 I S = Almost every parameter is temperature dependent. In many cases, the same equation for the temperature dependence is used for L2 and L Q p EASY OPTION: copy parameters directly from L2 but the equation for I S (T is the same as for c 1 (T: L2 -> L -> c 1 ( T I S ( T = c 1 I S T ζ v CT exp gb T T V T T Issue: Q p ( T const I S ( T c 1 ( T Q p ( T AP, MS 4

5 Automated parameter conversion from HICUM/L2 to HICUM/L Basic procedure (cont d Basic procedure Method for optimization used here => fit first derivative at nominal temperature In this case, v gb is adopted from L2 to L, therefore, ζ CT is adjusted. Also, simplified derivatives can be used Derivatives of all L2 parameters at nominal temperature dc dt c T 1 = ( ζ CT T T and dq p dt Q p z Ei ( V DEi + m g V T + v gbeeff = V T DEi T Derivative of the L parameter at nominal temperature di S dt I S ζ CT, L = T T In both cases, the derivative of the v gb related term in I S ( T and c 1 (T can be omitted. AP, MS 5

6 Automated parameter conversion from HICUM/L2 to HICUM/L Basic procedure (cont d Basic procedure Setting both sides equal results in I S ζ CT, L Since T I S = = c 1 ζ CT Q p z Ei ( V DEi + m g V T + v gbeeff Q T p c ( V DEi T T Q p 2 c Q p the equation simplifies to ζ CT, L = ζ CT Q p z Ei ( V DEi + m g V T + v gbeeff V DEi A strong reduction of the error over a large temperature range is achieved by using this method. Method is used for each L temperature related parameter (where required. ε r [%] ζ CT from L2 ζ CT adjusted Temp [K] AP, MS 6

7 Automated parameter conversion from HICUM/L2 to HICUM/L Conversion program Conversion program A MATLAB program was created implementing the conversion of all L parameters Modules for reading simulator specific netlists. Parameters are stored in a structure array. paral = convertl2tol(paral2, settings; Modules to save the converted parameters into library files of different formats. Settings allow the definition of the target version of L, the target temperature for optimization of some fine-tuning parameters for the parameter conversion. AP, MS 7

8 Automated parameter conversion from HICUM/L2 to HICUM/L Conversion program Conversion program (taking model versions into account HICUM/L2 version 2.2x and 2.3x as well as HICUM/L version 1.2 and 1.3 are supported Target version of HICUM/L can be selected. HICUM/L2 version follows directly from the given parameters Conversion of transfer current related parameters: HICUM/L2 v2.2x direct conversion HICUM/L v1.2 direct conversion special adjustment of reverse Early effect for selected temperature, but no fit over temperature possible HICUM/L2 v2.3x direct conversion HICUM/L v1.3 Future extensions will only include latest model versions (to keep programming effort manageable AP, MS 8

9 Automated parameter conversion from HICUM/L2 to HICUM/L Input file: netlist.ckt (ADS define tran_hicum2_23 (C B E S... M_hicum:qin C B E S model M_hicum HICUM2_23 C1= (L < 1.1? ( E- 33*(.735*L+.191*(L * (L : ( E- 33*(L *(L \... Support for ADS TRADICA Spectre (to be done ELDO (to be done... Output file: netlist_l.ckt (ADS define test_tran (C B E S... HIC_MOD:tran C B E S model HIC_MOD HICUM_1_2 is=8.8232e-19 \... Conversion program (Example Matlab program para_l2 = read_in_ads( netlist.ckt, L,1.4 para_l2 = C1: e settings = struct('lver','1.2'; para_l = convertl2tol(para_l2,settings para_l = is: e write_ads(para_l, nextlist_l.ckt, test_tran ; Conversion program Allows to set parameters for scalable libraries. Default values are taken directly from the model card. Specified parameters overwrite the default values. Read in from netlist Convert Write to netlist AP, MS 9

10 Automated parameter conversion from HICUM/L2 to HICUM/L Application to experimental data Application to experimental data Application to a 3 GHz SiGe-HBT technology from ST (L2 v2.3 -> L v1.3. I C, I B [ma] Temp (-4 C, 27 C, 125 C, for all following plots Measurement HICUM/L2 HICUM/L V w [V] BE sh w/o sh 6 Errors always L results with respect to L2, 4 not to measurements. 2 ε r [%] f T [GHz] Measurement HICUM/L2 HICUM/L Temp V [V] BE ε r [%] 3 L accuracy limit I [ma] C V [V] BE AP, MS 1

11 Automated parameter conversion from HICUM/L2 to HICUM/L R B [Ω] Application to experimental data Application to experimental data (internal values T HICUM/L2 HICUML/ V [V] BE C je [ff] Simplified models for base resistance and BE depletion capacitance in L compared to L HICUM/L2 (C jei +C jep HICUML/ T V [V] BE ε r [%] 15 1 ε r [%] V BE [V] V BE [V] AP, MS 11

12 Automated parameter conversion from HICUM/L2 to HICUM/L Application to experimental data Application to experimental data (small signal parameters Im (Y 11 [ms] Measurement HICUM/L2 HICUM/L T V [V] BE Re (Y 21 [ms] Small signal parameters are given at VBC= V and freq=1 GHz T 4 Measurement HICUM/L2 HICUM/L V [V] BE ε r [%] 3 2 ε r [%] V [V] BE V [V] BE AP, MS 12

13 Automated parameter conversion from HICUM/L2 to HICUM/L HICUM/L results and limitations HICUM/L results and limitations Very good results for DC and AC characteristics over a large temperature range. Errors in collector current (L with respect to L2 do not exceed 8%, errors for peak f T are all below 4% below the high-current region Larger deviations in the high current region outside of validity of L, same holds for the roll-off of f T. Simplified model used in L causes larger deviation in high current base resistance modulation. Simplified model for distributed input effects leads to deviations, especially for the base resistance may lead to deviations in high-speed large-signal behavior. Large deviations for small signal parameters in high current region. Both, Re(Y 21 and Im(Y 11 strongly depend on I C, which exponentially depends on V BE and especially in the high current region is strongly simplified compared to L2. AP, MS 13

14 Automated parameter conversion from HICUM/L2 to HICUM/L Summary Summary A procedure for automated direct parameter conversion from HICUM/L2 to HICUM/L was implemented saves significant effort for L parameter extraction Parameters are optimized with respect to temperature equations allows usage in temperature critical circuits (e.g. bandgap reference Excellent agreement for DC and AC characteristics is obtained within the validity limitations of HICUM/L Method and results submitted as paper to SCD 211 AP, MS 14