Analog Circuits and Mixed Circuits Design
The OpenEEG project is about making plans and software for do-it-yourself EEG devices available for free (as in GPL). It is aimed toward amateurs who would like to experiment with EEG. OpenEEG hardware – Amplifiers I found the amplifier designs extremely good as a learning material. – ananth Design documentation Amplifier schematic [55kb] (aka analogue board; contains two amplifiers) and digital board schematic [48kb] as images.
This is yet another Application Note of Exar found in- “Applications Data Book” June 1981. The Seven Scanned Pages as attachments can be viewed and studied at … Application Note – AN-03 – Active Filter Design with IC Op-Amps “This application note is intended to familiarize the filter designer with the fundamentals of active filter design, using monolithic IC op amps. It presents a table of transfer functions and network equations for high-pass, low-pass, band-pass and band-reject filters. Several design examples are given to illustrate the respective merits and limitations of various filter configurations. Particular emphasis is given to applications [Read More ....]
An analog electrical engineer from Cleveland, OH. Writes Reviews on Semiconductors and Articles on Enginnering in his Tech Blog. Chris Gammell – Analog Design Notes Consult Chris Gammell for your Product Design. Analog circuit design, including signal conditioning, amplification, control loops, input protection and power circuitry. Digital hardware design for your embedded project. Interface – @Chris_Gammell
“ADI microcontroller and integrated amplifier technologies support ultra low power, small size, and AAMI-EC13 performance level requirements for portable ECG designs.” AD8235: 40µA Micropower Instrumentation Amplifier in WLCSP Package The AD8235 is the industry’s smallest, lowest power instrumentation amplifier. It has rail to rail inputs and outputs and can operate on voltages as low as 1.8V. 128 Channel, 24-bit Current-to-Digital ADC for High Slice Count CT Scanners The ADAS1128 lowers CT system cost and enables enhanced imaging using the industry’s highest level of channel integration and speed. From – Analog Devices Healthcare
Mixed Circuits Analog with Digital Here are some circuits that have both Analog and Digital Signals in them. At one time i wanted to make reed relays, it was a good spot to be in, as it was used in Telecommunications. Even Small Office EPABX systems would have quite a Few of them. It was Simple, get some reeds from OKI and wrap them up in some copper coil and Pot them in a plastic can with epoxy. Before i could get even some trials out, the market was flooded with Good Quality Reed Relays from many. So the Lesson, [Read More ....]
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 [Read More ....]
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 [Read More ....]
4-20mA Conditioning – XTR101 TI BB These are Burr Brown Devices from TI. The BB Chips are excellent devices and High Precision, but a bit more expensive. These can be used when customer demands a Higher Quality and Precision. These are good for High Reliability Industrial Instrumentation. – delabs From TI Data Sheets – The XTR101 is a microcircuit, 4-20mA, two-wire transmitter containing a high accuracy instrumentation amplifier (IA), a voltage-controlled output current source, and dual-matched precision current reference. The XTR106 is a low cost, monolithic 4-20mA, two-wire current transmitter designed for bridge sensors. It provides complete bridge excitation (2.5V [Read More ....]
Building discrete semiconductor and passive designs, using Opamps and Mixed Design Circuits are the first step in electronics. Most consumer Electronics have a high analog circuit content. Even in Embedded Systems the interface design that matters for real time systems is an analog circuit. Here are some more analog points in my old notes. The Contact resistance of connectors, thermocouple effects in connectors and solder joints and thermal gradients over the PCB can cause errors when you measure in high resolution. High impedance points of circuit like 500 kilo ohm and above can pick up AC noise and DC leakage [Read More ....]
Proper documentation of product after design include Engineering Documentation, Production and Purchasing Inputs, Service Manuals, [Read More ....]
Smart Contactors. Timer, Thermostat. Over Current or Voltage. Trip or Limit. Three Phase Trip. High [Read More ....]
This is a Gadget Tutorial for this Article LED Running lights CD4017. This Demo shows [Read More ....]
This is the Photo of a RTD 3-W Mains Powered Temperature 4-20mA Transmitter. The Circuits [Read More ....]
The Security Guard duty monitor below, shown in eight circuits at Digital Circuits – 1 [Read More ....]
Product design and development is for the Innovative Engineer. Here Antronics have on display, some [Read More ....]
Embedded Systems Academy – Training Consulting “Expertise covers several microcontroller architectures and their development tool [Read More ....]