Analog Designs have to handle Linear Signals, Like 2.03 V and 35.3812 mA. Waveforms of all shapes from Straight Line DC Levels to the Jittery and Multi-Frequency Audio Waveforms.
Digital Designs manage Digital Signals, Like 0 and 5V Logic levels. All families of digital Logic, have some Threshold Limits and Voltage windows to determine Data Voltage or Current levels over Noise; this (Analog) comparator like action evaluates a High or Low Logic state. There are only two states, one is Low and the Other is High. 0 and 1 Respectively. The Third State in the word like Tristate, is a floating high impedance for Bus sharing between devices.
I would like to understand Mixed Circuit Designs as any circuit made of Valves, Discretes or Chips; in which both Analog signals and Digital Signals are Used. That would make an Analog Mux a Mixed Circuit, so also a PLL and a VCO.
Mixed Interface and Signal Circuits
Mixed Signal IC or ASIC are chips that are mainly Digital on the Core but have peripheral I/O within the chip to interface with the real world outside, over Analog Signals. Sensors and Actuators use signals in the analog language. The CPU with its Math Power, speaks Digital Words, its behavior thus can be patterned by a Software Program.
RF Microwave and Communication Chips; Power Electronic PWM Integrated Circuits are Specialized Niche Mixed Sub-Domains.
Therefore any Student of Robotics, Multimedia and Instrumentation, must be good at these Mixed Designs and a master of C Programming.
Related Resources
Design Gopher Custom Search
Thursday, July 16, 2009
Mixed Electronic Designs
Mixed and Interface Circuits
Mixed and Interface Circuits :
Most of the sensor interface and instrument inputs are analog; even if it event based like a limit switch, analog circuit protection and signal conditioning is required before it reaches the level sensitive digital circuit blocks.
Starting with Schmitt triggers and to the VCO and A-D Converters, are grades of Mixed Circuits. I feel Comparators like LM339, Timers like the 555 and Phase Locked Loop PLL are fundamental mixed circuits as they have a analog voltage detection.
DSP and uC with built in A-D or D-A or even SOC are Public ASICs and Fall in the Embedded Systems Block. Public ASICs are not user specific, they can be branded, numbered and provided with Application notes for the use of the Design Departments of any firm. User Specific ASICs are custom built and have only an application with that manufacturer for a Specific Product type. This also protects the IP of Code and Device Design. Custom ASICs are limited to the Platform and Technologies for which they were designed. Then we have programmable and configurable chips other than uC for logic like PLD, CPLD, FPGA and SOC, there is even some talk of mixed or analog configurable chips.
It would be nice if they made a breadboard chip with 12 opamps, 24 comparators, Some PLD and a couple of uC. Then we certainly need software trimmable or tweakable Resistors and Trimpots. This is the Magnum Opus of EDA. A EDA Chip Printer may be coming soon ! (Affordable by small firms).
Read More - Mixed and Interface Circuits - delabs
Related Resources -
Wednesday, July 15, 2009
CMOS Mixed-Signal Circuit Design - R Jacob Baker
CMOS Mixed-Signal Circuit Design - R Jacob Baker
Published by Wiley-IEEE, ISBN 978-0-470-29026-2, 2nd Edition, 2009. The book's author is R. Jacob Baker. Buy at Amazon.com.
The CMOSedu Google Group is found here.
Wednesday, July 01, 2009
MCS48 Code for 80C39 Microcontroller
80C39 is a Cmos Version of 8048 the one that preceded 8031-8051. MCS48 is the set for that, MCS51 is the current set. Here is an example project for 80C39-8748-8749 microcontroller. This code was written by me, and it works. But the documentation is not complete or may have errors.
Process Controller code here 80C39 Code for MCS48 (editable spreadsheet online)
Example - using Google Docs & Spreadsheets you can write assembly code on a spreadsheet. In private collaboration with others anywhere in the world. And you can use the docs to make reports, manuals or catalogs for publishing in your blog for public view.
See a manual document i have on public view Sequential Timer Manual (editable document online).
The basics of control system design - George Ellis
Embedded Systems Design - Embedded.com
Reading the excellent articles above, i was reminded of an incident....
Proportional Controllers not only save energy, they can give a controlled finish or treatment to a job. An on-off controller or thermostat limit protection has to be used in series, this is to to stop a Runaway Process.
There was a real life instance when a Temperature cycling oven maker (environment chamber), faced large liabilities as an 8086 based profile controller and chart recorder just locked up and all the electronic equipment were roasted. Here even a bimetallic thermostat would have saved the day. Nowadays we have a watchdog timer to prevent such uP mishaps, but still use an analog controller in series as an over temperature trip. - Ananth
Monday, June 15, 2009
Test Measurement and Test jigs
Test Tools are needed for Troubleshooting and Repairing Electronic Gadgets, Equipment, Electrical Panels and Machines. Precision Instruments are required for calibration of field and machine control electronics. These are also required by the R&D engineer for design and development of new products and trying out new concepts.
In Production testing, Production Engineering, Quality Assurance QA-QC etc. You need to build Test Jigs, Configure Automated Testing depending on the size of project or budget allocated; yet it has to be made flexible, scalable and modular. These require instruments or blocks that can be adapted and reconfigured or even interface with a computing network for automated testing, reporting and analysis.
Special Electronics come with every tool or gadget these days, A Slide calipers has a LCD display, Digital Readouts on mechanical instruments can help measure even sub-microns easily. Analytical and Chemical Instrumentation is another specialized niche. Then we have medical instrumentation which is more demanding in quality and requires sensors that are small, very sensitive and safe.
Instrumentation goes into all these and beyond. The day we find water on mars, It is only because of a precision instrument at the helm of things.
Anantha Narayan
Digital and Logic Circuits Basics
Digital Logic :
Basic Digital Circuits
You can start learning digital circuits by learning the operation of logic gates, see an interactive gadget tutor Logic Gates.
Then you can test the basics with these tutor gadgets
Some Digital circuits i have explained Digital_Circuits - Mixed_Circuits.
Digital FAQ :
Dynamic Digital Tutors - 555 simulator
Usage of Schmitt trigger NAND Gates - I have a question about your Long Duration Timer circuit
Printer Sharing Without LAN - I am from Techno India college
Fuzzy Logic Links - please if you have some materials on Fuzzy logic control
Presettable Up-Down counter-timer - I am looking for a schematic for pre settable Up/Down counter
Seven Segment LED display - how is the circuit for driving a seven segment led
Timers and Counters :
Digital Timers, Counters and Clocks
Timers and Counters along with Analog Process Controllers formed the front end of Industrial Automation. Even today automation systems and control panels use analog timers and electromechanical counters. These are Indispensable. Analog + Digital combination controllers came next which were little bigger and offered better stability. They had thumbwheel switches as user interface in place of potentiometers.
uP based Systems with chips like 8085 came after that, they consumed more power and were big in size. The coming of Cmos uC like 80C31 made Process Instrumentation Small and SMD made even 48 X 48 DIN sizes possible. Now Analog and uC based designs are used in different applications. Digital Hybrids and uP instruments are not used as they were Transient-Technology Methods.