Ansys RedHawk

Definition

Ansys RedHawk is chip-level power integrity and reliability signoff software used to analyze power delivery network (PDN) voltage drop, electromigration, and thermal effects in integrated circuit designs before manufacturing. It is used by semiconductor design teams to verify that a chip's power grid can reliably deliver current to every transistor without excessive voltage drop or wire degradation that could cause the chip to fail or underperform.

Overview

As chips have grown denser and operate at lower voltages with higher current density, ensuring that power actually reaches every part of a chip cleanly has become a distinct engineering discipline from functional design, and RedHawk was built to address that need. It analyzes the power delivery network, the mesh of metal wires that carries current from external power pins to billions of individual transistors, checking whether voltage drop (IR drop) along that path stays within limits that keep circuits switching correctly and within timing. Mechanically, RedHawk takes the physical layout of a chip along with its power grid structure, switching activity data, and process technology models, then simulates current flow through the resistive and inductive network to compute voltage drop at every point on the chip under realistic workload conditions. It also performs electromigration analysis, checking whether current density in individual wires exceeds limits that would cause metal atoms to migrate over time and eventually break the connection, and it can extend this analysis into thermal effects, since temperature and current density interact. Within the signoff tool landscape, RedHawk is a specialized point tool focused specifically on power and reliability, distinct from timing signoff tools like Synopsys PrimeTime or physical verification tools that check manufacturing design rules; it is often used alongside those tools rather than replacing them. Its closest competitors are Cadence Voltus, which performs similar power integrity analysis, and Siemens EDA's power signoff offerings, with the choice often driven by which vendor's broader implementation flow a design team already uses. In practice, design teams run RedHawk analysis at multiple stages of chip development, from early power grid planning through final signoff before tapeout, since discovering a power integrity problem after manufacturing is far more expensive to fix than catching it during design. It is particularly critical for high-performance chips such as processors and GPUs, where large current swings during switching activity can create transient voltage droops that cause timing failures even when the average power delivery looks adequate. Running full-chip power integrity simulation is computationally intensive, requiring detailed extraction of the power grid's resistance and capacitance and simulation across many workload vectors, so teams often need to prioritize which scenarios and chip regions get full analysis versus faster approximate checks. RedHawk is not a substitute for good power grid architecture decided early in the design; it identifies problems but the fix, more metal, different grid topology, or decoupling capacitors, still requires design changes elsewhere in the flow.

Key Features

• Static and dynamic IR drop analysis across the full chip power grid
• Electromigration checking for wires and vias against reliability limits
• Thermal-aware analysis linking temperature to current density effects
• Vectorless and vector-based power integrity simulation modes
• Integration with physical layout and extraction data from design flows
• Multi-corner, multi-mode analysis across process and voltage conditions
• Sign-off-quality accuracy correlated with silicon measurements
• Support for advanced packaging and 3D-IC power analysis

Use Cases

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Frequently Asked Questions

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