This element is OBSOLETE and is replaced by the Mextram 504 BJT Model (MXTR504) element. Mextram 504 is Philips' most recent vertical bipolar transistor model. Compared to Mextram 503, this model has improved descriptions of transistor characteristics and easier parameter extraction. The improved transistor characteristics are achieved by changing some of the model's formulations. The resulting equations are much smoother, such that first-order and higher derivatives are better. The complete set of equations and derivation are found in references [1] and [2], respectively. Parameter extraction is improved by decreasing parameter interdependence, without losing the physical basis of the model. As a result, the number of parameters has increased from 62 to 71.
MXTR504N is a full implementation of Philips' Mextram 504 model. It includes self-heating, which adds complexity to the model and increases the computation time. Due to the model's improved smoothness, tests show that MXTR504, with self-heating disabled, converges in general better than MXTR503.
Name | Description | Unit Type | Default |
---|---|---|---|
ID | Element ID | MX1 | |
*NPN | NPN (flag, information only) | 1 | |
*PNP | PNP (flag, information only) | 0 | |
*LEVEL | Release (Information only) | 504 | |
*EXMOD | Flag for extended modeling of reverse current gain | 1.0 | |
*EXPHI | Flag for distributed high frequency effects in transient simulations | 1 | |
*EXAVL | Flag for extended modeling of avalanche currents | 0.0 | |
*IS | Collector-to-emitter saturation current | Amperes | 5e-017A |
*BF | Forward current gain | 215 | |
*XIBI | Fraction of ideal base current from sidewall | 0.0 | |
*IBF | Saturation current of the non-ideal forward base current | Amperes | 2e-14A |
*VER | Reverse Early voltage | Voltage | 2.5V |
*VEF | Forward Early voltage | Voltage | 44V |
*MLF | Non-ideality factor of the non-ideal forward base current | 2 | |
*VLF | Cross-over voltage of the non-ideal forward base current | Voltage | 0.5V |
*IK | High-injection knee current | Amperes | 15.0e-3A |
*BRI | Ideal reverse current gain | 7 | |
*IBR | Saturation current of the non-ideal base current | Amperes | 1e-12 |
*VLR | Cross-over voltage of the non-ideal reverse base current | Voltage | 0.2 |
*XEXT | Parameter dependency of VBC1 | 0.63 | |
*WAVL | Epilayer thickness used in weak-avalanche model | 1.1 | |
*VAVL | Voltage determining curvature of avalanche current | Voltage | 3V |
*QBO | Base charge at zero bias | 1.2e12 | |
*ETA | Factor of the built-in field base) | 4.0 | |
*AVL | Weak avalanche parameter | 50.0 | |
*EFI | Electric field intercept | 0.7 | |
*IHC | Critical current for hot carriers | Amperes | 4 |
*AXI | Smoothness parameter for the onset of quasi-saturation | 0.3 | |
*RCC | Constant part of the collector resistance | Resistance | 25.0 ohm |
*RCV | Resistance of the unmodulated epilayer | Resistance | 150 |
*SCRCV | Space charge resistance of the epilayer | Resistance | 1250 |
*SFH | Current spreading factor epilayer | Resistance | 0.6 ohm |
*RBC | Constant part of the base resistance | Resistance | 23 |
*RBV | Variable part of the base resistance at zero bias | Resistance | 18 |
*RE | Emitter series resistance | Resistance | 2.0 ohm |
*TAUNE | Minimum delay time of neutral and emitter charge | Conductance | 0.3e-9s |
*MTAU | Non-ideality factor of the neutral and emitter charge | 1.18 | |
*TAUE | Minimum transit time of stored emitter charge | Time | 0.002ns |
*TAUB | Transit time of stored base charge | Time | 0.0042ns |
*TEPI | Transit time of stored epilayer charge | Time | 0.041ns |
*TAUR | Transit time of reverse extrinsic stored base charge | Time | 0.52ns |
*CJE | Zero bias BE depletion capacitance | Faraday | 0.25e-12F |
*VDE | BE built-in voltage | Voltage | 0.9V |
*PE | BE grading coefficient | 0.33 | |
*XCJE | Reaction of BE capacitance to the sidewall | 0.5 | |
*CBE0 | Emitter-base overlap capacitance | 0 | |
*CJC | Zero bias BC depletion capacitance | Faraday | 0.13e-12F |
*VDC | BC built-in voltage | Voltage | 0.6V |
*PC | BC grading coefficient | 0.4 | |
*XP | Constant part of CJC | 0.2 | |
*MC | Collector current modulation coefficient | 0.5 | |
*XCJC | Fraction of BE capacitance under emitter | 0.1 | |
*CBC0 | Collector-base overlap capacitance | 0 | |
*TNOM | Reference (extraction) temperature | Celsius | 25^{o}C |
*TEMP | Ambient (baseplate) temperature | Celsius | 25^{o}C |
*VGE | Emitter Bandgap | Voltage | 1.01V |
*VGB | Base Bandgap | Voltage | 1.18V |
*VGC | Collector Bandgap | Voltage | 1.205V |
*VGJ | EB Bandgap | Voltage | 1.1V |
*VI | Ionization voltage base dope | Voltage | 0.4V |
*NA | Maximum base dope (per cm^3) | 3e17 | |
*ER | VLF and VLR temp coefficient | 0.002 | |
*DEG | Bandgap difference over the base | 0 | |
*XREC | Pr-factor of the recombination part of IB1 | 0 | |
*AQB0 | Temperature coefficient of the zero bias base charge | 0.3 | |
*AE | Temperature coefficient of the resistivity of the emitter | 0 | |
*AB | Base resistance temp coefficient | 1.35 | |
*AEPI | Epilayer temp coefficient | 2.15 | |
*AEX | Extrinsic base temp coefficient | 1.0 | |
*AC | Buried layer temp coefficient | 4.0 | |
*DVGBF | Band-gap voltage difference of forward current gain | Voltage | 0.05V |
*DVGBR | Band-gap voltage difference of reverse current gain | Voltage | 0.045V |
*DVGTE | Band-gap voltage difference of emitter stored charge | Voltage | 0.05V |
*KF | Base current 1/f noise | 2e-6 | |
*KFN | Nonideal base 1/f noise | 2e-6 | |
*AF | 1/f noise exponent | 1.0 | |
*ISS | base-substrate saturation current | Amperes | 6.0e-16A |
*IKS | Knee current of the substrate | Amperes | 0.005e-3A |
*CJS | Zero-voltage substrate capacitance | Faraday | 1.0e-12F |
*VDS | CS built-in voltage | Voltage | 0.5V |
*PS | CS grading coefficient | 0.33 | |
*RTH | Thermal resistance | 300 | |
*CTH | Thermal capacitance | 3e-9 | |
*VGS | Substrate Bandgap | Voltage | V |
*AS | =AC for closed buried layer; =AEPI for open buried layer. | 2.15 | |
*NFLAG | Noise flag; 1=ON, 0=OFF | ||
*MULT | Number of devices in parallel | 1 |
* indicates a secondary parameter
Parameter default values correspond to HSPICE default values and correspond to those listed as test parameters in Philips' documentation [1].
The range of many of the model parameters is restricted. In spite of extensive error-trapping in the Cadence® AWR® Microwave Office® software implementation, some parameter errors may not be trapped. See [1] for details on such restrictions.
This model is mapped into HSPICE as a NPN G-device with parameters LEVEL and VERS set to 6 and 504, respectively. The complete set of equations is too complex to be listed here. Consult the references for specific information. Ref. [1] defines the model in detail and ref. [2] contains the derivation of the model.
Like Mextram 503, Mextram 504 is an advanced model and should be used only where the need for accuracy justifies its complexity, and where parameter libraries are available. Care must be exercised when self-heating is enabled.
This element does not have an assigned layout cell. You can assign artwork cells to any element. See “Assigning Artwork Cells to Layout of Schematic Elements” for details.