Overview
IEC TS 62404:2007 - Logic digital integrated circuits (IMIC v1.3) defines a standardized I/O interface model for integrated circuits to support accurate electrical analysis at chip, package and module levels. The Technical Specification standardizes the electrical modeling of input/output signals, power supply and ground terminals so that simulators and EDA tools can analyze signal integrity, power/ground bounce and board-level electrical behavior without exposing vendor proprietary process parameters.
Key points:
- Model language: extended SPICE-style circuit descriptions.
- Hierarchy: separate, interoperable IC, package and module model files.
- Device representation: non-linear devices expressed in 1D/2D/3D table formats and equivalent circuits.
- Relation to IBIS: complements and extends IBIS (IEC 62014‑1) by covering power/ground currents, internal circuitry and package/module effects.
Key topics and requirements
- Model structure and delivery: Defines data structures and file elements for IC model files, package model files and module model files to allow independent generation and exchange.
- Circuit description rules: Extended SPICE syntax and unified description rules to model simple and complex buffers, power/ground interconnects and package parasitics.
- Device equivalents and characteristics: Includes diagrams and tables for diodes, MOS (NMOS/PMOS) and bipolar equivalents, plus grid-based characteristic data for non-linear behavior.
- Levels of modeling: Introduces modeling levels so that users can exchange only the level of detail required for a given analysis (e.g., fast system-level versus detailed transistor-level).
- Simulation compatibility: Focus on producing netlists and models suitable for circuit-level simulation of printed circuit boards and I/O buffers.
- Interoperability with IBIS: Provides means to derive IBIS data from IMIC models and to overcome IBIS limitations for power/ground and multi-stage buffer effects.
Applications
- Signal integrity analysis (rise/fall waveforms, crosstalk)
- Power integrity and power/ground bounce simulation
- Board- and module-level circuit simulation including package parasitics
- EMI/EMC pre-compliance modeling where richer internal-device or package detail is needed
- Generation of vendor-supplied models for EDA tools while protecting proprietary process details
Who uses this standard
- Semiconductor manufacturers and device vendors preparing I/O models
- EDA and simulator tool developers implementing modeling support
- PCB, module and system designers performing SI/PI/EMI analysis
- Signal integrity and power integrity engineers requiring accurate I/O and package behavior
Related standards
- IEC 62014-1 (IBIS) - Input/Output Buffer Information Specification: referenced normative standard; IMIC is designed to complement and extend IBIS capabilities.
Keywords: IEC TS 62404:2007, IMIC version 1.3, I/O interface model, integrated circuit modeling, extended SPICE, package model, module model, signal integrity, power/ground bounce, IBIS, electrical modeling.