ANXPLORER Datasheet, PDF (2/4 Pages) List of Unclassifed Manufacturers – EDA TOOL FOR SCHEMATIC LEVEL OPTIMIZATION OF ANALOG & RF CIRCUITS

AnXplorer: EDA Tool for Schematic Level Optimization of Analog & RF Circuits
variate, muti-objective optimization algorithm for arbitrary cost
functions having multiple local optima. It can be used by circuit
designers to quickly explore different circuit schematics to iden-
tify the right choice. It also helps in finding a robust design solu-
tion against variations in the manufacturing process, tempera-
ture, and supply voltage. It takes as input an unsized SPICE net-
list along with design specifications and constraints. It calls a
SPICE simulator in a loop to evaluate the circuit at different test
points. Finally, it produces an optimized and centered netlist.
Inputs
• ^{SPICE netlist of circuit to be optimized, and/or a set of design}
equations the user wants to optimize.
• ^{Set of design objectives which the circuit should meet and a}
set of constraints which must be honored. Any quantity which
can be simulated and measured can be a design objective.
• ^{Set of design variables which the tool can tune, along with}
their allowed range of values. Typically, these design variables
represent transistor dimensions, bias voltages, etc.
• ^{Set of “corners”, including manufacturing process corners (e.g.}
fast, typical, slow), different temperatures and different supply
voltages. AnXplorer optimizes the circuit to ensure that design
objectives are met across these corners.
Outputs
Figure 1: Inputs and outputs of AnXplorer
• ^{An optimized and centered circuit netlist, which meets or}
exceeds the design objectives across all the user specified cor-
ners.
• ^{An exploration database, which is a persistent storage for all}
design points explored by the tool. This database can be que-
ried and used for effective trade-off analysis between conflict-
ing design objectives.
Pictorially, the inputs and outputs are shown in figure 1. Figure 2
explains how AnXplorer automates the existing design flow.
Figure 2: Analog design flow with AnXplorer
Currently, AnXplorer works seamlessly with several industry
standard SPICE simulators.
DIFFERENTIATING FEATURES
Design equation based optimization: In addition to simulation
based design optimization, AnXplorer also supports design equa-
tion based optimization, or a combination of both. Unlike
gradient-search based tools, AnXplorer supports arbitrary func-
tions with multiple local and global optima.
Hierarchical design objectives: Unlike a weight based prioritiza-
tion of multiple objectives, commonly used in other optimization
tools, AnXplorer employs a hierarchical arrangement for design
objectives. The user specifies the relative order of importance of
each objective, instead of a weight. This is specified in the form of
a directed graph. The tool tries to achieve the objective with
higher priority before optimizing the other objectives.
Trade-off analysis with exploration database: AnXplorer records
all design points explored during the optimization process and
these are stored in a persistent database. This database can be
queried. This creates an effective tool for “what-if” analysis (how
much can one objective be achieved, if another is constrained
below a certain value?). It also enables trade-off analysis for con-
flicting objectives (e.g. circuit area and noise, speed and power) if
all objectives cannot be realistically met.
Implicit objectives: In addition to explicit objectives specified by
the user, AnXplorer imposes certain implicit objectives on the
operating condition of devices. Transistors which are supposed to
be in saturation are pushed deep into saturation. This ensures an
inherently robust design.
VALUE ADDITION
Productivity improvement: AnXplorer improves engineering
efficiency by at least 5X. This is achieved by automating the
manual and routine job of sizing circuit elements to meet design
objectives. This leads to faster time-to-market. The productivity
improvement enabled by AnXplorer has other benefits as well. It
helps engineers to quickly judge the suitability of any given
schematic for a particular purpose, and thus helps in evaluating
multiple options before selecting a topology. It also helps less
experienced engineers to take up challenging design tasks.
Yield improvement: AnXplorer helps achieve a robust design
point for any circuit, so that it meets its design objectives in the
face of variation in the manufacturing process, temperature, and
supply voltage. This is a major challenge in the current manual
design flow, and is responsible for most silicon re-spins. AnX-
plorer, by rigorously exploring the design space for robust solu-
tions, improves yield and increases the chances of first-time sili-
con success, thereby saving millions.
Porting across process nodes: As manufacturing processes
change every day, it becomes necessary to port designs from one
process node to another. This involves re-sizing the circuit ele-
ments so that the circuit meets its objectives in the new process.
AnXplorer can automate this task. This is especially helpful for
analog IP companies who often have to re-target the same design
for different customer foundries.
EXAMPLES OF SIMULATION BASED OPTIMIZATION
Two-stage OpAmp
Source: Krasnicki, M. J., Phelps, R., Hellums, J. R., McClang, M.,
Rutenbar, R. A., Carley, L. R., “ASF: A practical simulation-based