Cadence® system design and verification solutions, integrated under our System Development Suite, provide the simulation, acceleration, emulation, and management capabilities.
System Development Suite Related Products A-Z
Cadence® digital design and signoff solutions provide a fast path to design closure and better predictability, helping you meet your power, performance, and area (PPA) targets.
Full-Flow Digital Solution Related Products A-Z
Cadence® custom, analog, and RF design solutions can help you save time by automating many routine tasks, from block-level and mixed-signal simulation to routing and library characterization.
Overview Related Products A-Z
Driving efficiency and accuracy in advanced packaging, system planning, and multi-fabric interoperability, Cadence® package implementation products deliver the automation and accuracy.
Cadence® PCB design solutions enable shorter, more predictable design cycles with greater integration of component design and system-level simulation for a constraint-driven flow.
An open IP platform for you to customize your app-driven SoC design.
Comprehensive solutions and methodologies.
Helping you meet your broader business goals.
A global customer support infrastructure with around-the-clock help.
24/7 Support - Cadence Online Support
Locate the latest software updates, service request, technical documentation, solutions and more in your personalized environment.
Cadence offers various software services for download. This page describes our offerings, including the Allegro FREE Physical Viewer.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
This course combines our Allegro PCB Editor Basic Techniques, followed by Allegro PCB Editor Intermediate Techniques.
Virtuoso Analog Design Environment Verifier 16.7
Learn learn to perform requirements-driven analog verification using the Virtuoso ADE Verifier tool.
Exchange ideas, news, technical information, and best practices.
The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information.
It's not all about the technlogy. Here we exchange ideas on the Cadence Academic Network and other subjects of general interest.
Cadence is a leading provider of system design tools, software, IP, and services.
Hello all, I am posting my first question here trying to appeal to RF experts. I have designed a power amp to deliver around 20W into a 1 Ohm load at 200KHz sine. The amplitude is more or less constant, the frequency is constant, the load varies a bit. The supply rails are +/-12V. My design uses 2 or 3 pairs of output transistors (2 pairs did not work well, tried 3 pairs still no go).
The amplifier works perfectly until we reach a point where the load gets too heavy (too small) in conjunction with a high amplitude signal. At that moment, we get immedaite thermal runaway so fast that the heat hardly makes it out of the transistor cases and cross-conduction - chicken and egg - I am not sure what causes what.
The problem is immediately fixable by not letting the load drop so low, or by simpoly adding another volt to the supply rails. I attach 3 scope snapshots taken at the emitter resistors.
The first picture shows normal operation, load is around 2-2.5 Ohms. You can see the transistors opening and closing properly without overlaps.
Second picture shows what happens when the load gets too low, a few seconds in the transistors have already remained open for far longer in the cycle than they should resulting in thermal runaway and current limit kicking in.
Third picture shows the problem corrected by increasing the rails by 1.5V.
If anyone has experience with RF power amps please help.
This looks as if it is more of a discrete RF design question, whereas this forum is primarily for RF IC Design. In general most of the questions here are more EDA-related rather than design related - so maybe you would be better asking this at somewhere like The Designer's Guide?