Altium vs. OrCAD — Your Complete PCB Design & Layout Comparison Guide

 

Introduction

In the world of Printed Circuit Board (PCB) design, choosing the right software tool is crucial for efficiency, accuracy, and overall project success. Two of the most prominent players in this field are Altium Designer and OrCAD. Both offer comprehensive solutions for electronic design automation (EDA), but they differ in various aspects, from user interface to advanced features and pricing models.

This article aims to provide a detailed comparison between Altium Designer and OrCAD, helping engineers, designers, and organizations make an informed decision when selecting a PCB design tool. We'll explore various aspects of both software packages, including their strengths, weaknesses, and unique features, to give you a comprehensive understanding of how they stack up against each other.

Overview of Altium Designer

Altium Designer is a comprehensive PCB design software suite developed by Altium Limited. Known for its unified design environment, Altium Designer offers a range of features from schematic capture to PCB layout, 3D visualization, and FPGA development.

Key Features of Altium Designer

1. Unified design environment
2. Advanced PCB layout and routing capabilities
3. 3D PCB visualization and MCAD integration
4. Robust library management system
5. High-speed design tools
6. FPGA development support
7. Team collaboration features

Overview of OrCAD

OrCAD, now part of Cadence Design Systems, is a suite of EDA tools that includes OrCAD Capture for schematic design and OrCAD PCB Designer for board layout. It's known for its powerful simulation capabilities and integration with other Cadence tools.

Key Features of OrCAD

1. Comprehensive schematic capture (OrCAD Capture)
2. Advanced PCB layout and routing (OrCAD PCB Designer)
3. Powerful simulation tools (PSpice)
4. Integration with Cadence Allegro for advanced designs
5. Constraint-driven design flow
6. Signal integrity analysis
7. Component Information System (CIS)

User Interface and Ease of Use

The user interface and overall usability of a PCB design tool significantly impact productivity and user satisfaction. Let's compare Altium Designer and OrCAD in this aspect.

Altium Designer

• Unified Environment: All tools are integrated into a single application.
• Modern Interface: Sleek, customizable interface with ribbon-style menus.
• Intuitive Workflow: Designed for a smooth transition between different design stages.
• Customizable Hotkeys: Extensive keyboard shortcut support for faster operation.

OrCAD

• Modular Structure: Separate applications for schematic capture (Capture) and PCB layout (PCB Editor).
• Traditional Interface: Classic Windows-style interface, familiar to long-time users.
• Customizable Toolbars: Users can modify toolbars and menus to suit their preferences.
• Command-Line Interface: Offers a powerful command-line interface for advanced users.

Comparison Table: User Interface and Ease of Use

Aspect
Altium Designer
OrCAD
Interface Style
Modern, ribbon-based
Traditional, menu-based
Learning Curve
Moderate
Steep for new users
Customization
Highly customizable
Customizable, but less intuitive
Integration
Fully integrated suite
Modular with separate applications
Workflow
Streamlined
Can be fragmented between modules

Schematic Capture

Schematic capture is the first step in PCB design, where the circuit is logically defined. Both Altium Designer and OrCAD offer robust schematic capture tools, but with different approaches and features.

Altium Designer Schematic Capture

• Unified Environment: Seamless integration with PCB layout.
• Multi-Channel Design: Supports complex multi-channel designs.
• Real-Time Error Checking: Immediate feedback on design errors.
• Advanced Annotation: Automatic and cross-sheet annotation features.
• Hierarchical Design: Supports top-down and bottom-up design methodologies.

OrCAD Capture

• Powerful Editing Tools: Comprehensive set of editing and manipulation tools.
• Hierarchical Blocks: Supports hierarchical design with reusable blocks.
• TCL Scripting: Extensive scripting capabilities for automation.
• Component Information System (CIS): Integrated component management.
• Integration with PSpice: Direct link to simulation tools.

Comparison Table: Schematic Capture Features

Feature
Altium Designer
OrCAD Capture
User Interface
Modern, intuitive
Traditional, feature-rich
Multi-Channel Design
Advanced support
Supported
Real-Time Error Checking
Comprehensive
Basic
Scripting Capabilities
SchDoc API, Delphi scripting
TCL scripting
Component Management
Integrated library system
Component Information System (CIS)
Simulation Integration
Basic
Advanced (with PSpice)

PCB Layout and Routing

PCB layout and routing are critical aspects of the design process, where the logical schematic is transformed into a physical board design. Both Altium Designer and OrCAD offer powerful tools for this purpose, but with different strengths and approaches.

Altium Designer PCB Layout and Routing

• Interactive Routing: Advanced interactive routing with real-time DRC.
• ActiveRoute: AI-assisted auto-routing technology.
• Differential Pair Routing: Sophisticated tools for high-speed differential pairs.
• Layer Stack Manager: Comprehensive layer stack definition and management.
• Rigid-Flex Support: Advanced rigid-flex and multi-board design capabilities.
• Length Tuning: Interactive and automated length tuning tools.

OrCAD PCB Designer

• Constraint-Driven Layout: Powerful constraint management system.
• SKILL Scripting: Extensive customization through SKILL programming language.
• Gloss and Cleanup: Automated trace clean-up and optimization tools.
• Allegro Integration: Seamless upgrade path to Cadence Allegro for complex designs.
• High-Speed Routing: Advanced tools for high-speed design challenges.
• Sketch Router: Interactive routing assistant for efficient trace placement.

Comparison Table: PCB Layout and Routing Features

Feature
Altium Designer
OrCAD PCB Designer
User Interface
Modern, unified
Traditional, powerful
Auto-Routing
ActiveRoute technology
Allegro AiDT (Auto-interactive Delay Tuning)
Interactive Routing
Advanced with real-time DRC
Powerful with constraint checking
High-Speed Design Tools
Comprehensive
Extensive, especially with Allegro integration
Flex and Rigid-Flex Design
Native support
Supported with add-ons
Script-Based Automation
Delphi scripting
SKILL scripting

Library Management

Effective library management is crucial for maintaining consistency and efficiency in PCB design. Both Altium Designer and OrCAD offer library management systems, but with different approaches and strengths.

Altium Designer Library Management

• Unified Library System: Integrated management of schematic symbols, PCB footprints, and 3D models.
• Vault Technology: Secure, version-controlled component management.
• Component Links: Direct links to supplier data for real-time pricing and availability.
• Templates and Wizards: Tools for quick creation of new library components.
• Library Health Check: Automated checks for library integrity and completeness.

OrCAD Library Management

• Component Information System (CIS): Integrated database for component management.
• OrCAD Library Builder: Tool for creating and managing library components.
• Integration with Supply Chain: Links to component distributors for up-to-date information.
• Part Type Creation: Tools for creating generic part types for reuse.
• Library Sharing: Capabilities for sharing libraries across teams and projects.

Comparison Table: Library Management Features

Feature
Altium Designer
OrCAD
Library Structure
Unified (symbols, footprints, 3D models)
Separate libraries for symbols and footprints
Version Control
Built-in with Vault technology
Through external version control systems
Supply Chain Integration
Direct supplier links
Through CIS and partner integrations
Component Creation Tools
Advanced with templates and wizards
Comprehensive with Library Builder
Database Integration
Supported with Altium 365
Native with CIS

Simulation Capabilities

Circuit simulation is an essential part of the design process, allowing engineers to verify circuit behavior before prototyping. Altium Designer and OrCAD have different approaches to simulation capabilities.

Altium Designer Simulation

• Mixed-Signal Simulation: Basic SPICE-based simulation engine.
• Signal Integrity Analysis: Tools for signal integrity and crosstalk analysis.
• Power Distribution Network Analysis: Capabilities for PDN analysis and optimization.
• Integration with Third-Party Tools: Support for integration with more advanced simulation tools.

OrCAD Simulation (PSpice)

• Advanced SPICE Simulation: Powerful analog and mixed-signal simulation engine.
• Extensive Model Library: Large library of vendor-supplied and generic component models.
• Advanced Analysis: AC, DC, transient, noise, sensitivity, and Monte Carlo analyses.
• Behavioral Modeling: Support for creating behavioral models of complex components.
• Integration with PCB Layout: Direct link between simulation and PCB design.

Comparison Table: Simulation Capabilities

Feature
Altium Designer
OrCAD (PSpice)
Simulation Engine
Basic SPICE
Advanced PSpice
Signal Integrity Analysis
Integrated
Advanced with SI add-on
Power Integrity Analysis
Basic PDN analysis
Comprehensive with PI add-on
Model Library
Limited
Extensive
Behavioral Modeling
Limited
Advanced
Integration with Layout
Tight integration
Seamless with OrCAD PCB Designer

3D Visualization and Integration

3D visualization has become increasingly important in PCB design, allowing designers to verify mechanical fit and aesthetics. Both Altium Designer and OrCAD offer 3D capabilities, but with different levels of integration and features.

Altium Designer 3D Capabilities

• Native 3D PCB Editing: Fully integrated 3D editing environment.
• STEP Model Support: Import and export of STEP models for components and boards.
• Clearance Checking: 3D clearance and collision detection.
• Folded Board View: Support for flex and rigid-flex board visualization.
• MCAD Collaboration: Direct integration with mechanical CAD tools.

OrCAD 3D Capabilities

• 3D Visualization: 3D viewing capabilities through the Allegro platform.
• STEP Import/Export: Support for STEP models in the PCB Editor.
• Basic Clearance Checking: 3D clearance verification tools.
• Integration with Mechanical Tools: Collaboration features with MCAD tools.

Comparison Table: 3D Visualization Features

Feature
Altium Designer
OrCAD
Native 3D Editing
Yes
Limited (through Allegro)
STEP Support
Comprehensive
Supported
Clearance Checking
Advanced 3D checking
Basic 3D verification
Flex/Rigid-Flex Visualization
Native support
Limited
MCAD Integration
Direct with major MCAD tools
Through Allegro and partners

Design Rule Checking and Verification

Design Rule Checking (DRC) is crucial for ensuring that PCB designs meet manufacturing and electrical requirements. Both Altium Designer and OrCAD offer robust DRC capabilities, but with different features and interfaces.

Altium Designer DRC

• Real-Time DRC: Continuous design rule checking during layout.
• Customizable Rules: Extensive set of configurable design rules.
• Electrical Rule Checking: Advanced ERC in both schematic and PCB.
• Visual Clearance Checking: Interactive clearance checking in 2D and 3D.
• Batch DRC: Comprehensive batch design rule checking.

OrCAD DRC

• Constraint Manager: Powerful tool for setting and managing design constraints.
• Physical and Spacing Checks: Comprehensive checks for physical and spacing rules.
• Electrical Rule Checking: Advanced ERC in Capture and PCB Editor.
• Design for Manufacturing (DFM) Checks: Built-in DFM rule checks.
• Custom Checks: Ability to create custom design rules using SKILL.

Comparison Table: Design Rule Checking Features

Feature
Altium Designer
OrCAD
Real-Time DRC
Comprehensive
Basic
Rule Customization
Extensive
Advanced with SKILL
Electrical Rule Checking
Integrated in schematic and PCB
Comprehensive in Capture and PCB Editor
3D Clearance Checking
Native support
Limited
DFM Checks
Included
Extensive

High-Speed Design Features

As digital circuits become faster and more complex, high-speed design features are increasingly important in PCB design tools. Both Altium Designer and OrCAD offer capabilities in this area, but with different strengths.

Altium Designer High-Speed Features

• Impedance Profiling: Tools for impedance calculation and trace profiling.
• Length Tuning: Interactive and automatic length tuning for high-speed signals.
• Differential Pair Routing: Advanced differential pair routing capabilities.
• Signal Integrity Analysis: Built-in signal integrity simulation tools.
• PDN Analysis: Power distribution network analysis features.

OrCAD High-Speed Features

• Constraint Manager: Powerful tool for managing high-speed design constraints.
• Allegro Integration: Access to advanced Allegro high-speed design tools.
• Signal Integrity Simulation: Comprehensive SI analysis with optional add-ons.
• Topology Planning: Advanced topology planning and management.
• Delay Tuning: Sophisticated delay tuning capabilities.

Comparison Table: High-Speed Design Features

Feature
Altium Designer
OrCAD
Impedance Control
Advanced
Comprehensive
Length Tuning
Interactive and automatic
Advanced with Allegro
Differential Pair Routing
Sophisticated
Powerful
Signal Integrity Analysis
Integrated
Advanced with add-ons
Constraint Management
Rule-based
Constraint Manager

Multi-Board and Hierarchical Design

Complex electronic systems often require multi-board designs and hierarchical structuring. Both Altium Designer and OrCAD provide solutions for these advanced design scenarios.

Altium Designer Multi-Board and Hierarchical Design

• Multi-Board Assembly: Native support for multi-board system design.
• Hierarchical Schematic Design: Advanced hierarchical design capabilities.
• Reusable Modules: Support for creating and managing reusable design blocks.
• System-Level Simulation: Ability to simulate multi-board systems.
• 3D Multi-Board Visualization: Integrated 3D viewing of multi-board assemblies.