Tag Archives: analog

How-to use PWM to Generate Analog Voltage in Digital Circuits

PWM_period_0

Maurizio @ emcelettronica.com tipped us with his latest article on how to generate analog voltages using a microcontroller.

Many times, designers are faced with the need of generating analogue or analog voltage levels in purely digital circuits. Although the market provides today a very broad range of dedicated digital-to-analogue converters, putting such a device in the schematic has a negative impact on the overall cost of the system.

How-to use PWM to Generate Analog Voltage in Digital Circuits – [Link]

Generating Analog Voltage with Digital Circuit

Fig0012

Maurizio show us how to generate an analog voltage using a microcontroller and some resistors.

The purpose of this article is how to generate analog voltage with digital circuit. Although the market provides today a very broad range of dedicated digital-to-analogue converters, putting such a device in the schematic has a negative impact on the overall cost of the system. There are however, cheap methods of creating the required voltage levels, and even of generating pseudo-analogue signals, using purely digital means.

Generating Analog Voltage with Digital Circuit – [Link]

Analog Devices AD587KN 10V reference chip

10vref_ad587-1

SteelCity Electronics published an article about Analog Devices AD587KN 10V reference:

I recently got hold of an Analog Devices AD587KN high precision 10.000V reference chip.
This model of chip has an output value of 10.000V ± 5mV (that is, an output value of 9.995V to 10.005V) straight out of the factory. A voltage drift of 10ppm/°C at 25°C meaning that the output voltage will drift by 10μV for each 1°C the chip is exposed to. Additionally, the chip has a voltage trim input, so if you have access to a precision voltmeter, the chip’s output value can be adjusted even closer to 10.000V.
Alternatively, the chip’s output can be trimmed to a value of 10.24V. You may think that a value of 10.24V seems like a strangely familiar number. A value of 1024 is the decimal representation of 10bits, that is 2∧10 = 1024. Why would I want a voltage reference that outputs a value of 10.24V? Because it makes any ADC or DAC conversions much simpler.

Analog Devices AD587KN 10V reference chip  – [Link]

A data-acquisition system on a chip

AD5592R-600x212

by Martin Rowe @ edn.com:

Multifunction data-acquisition systems have been around for a long time as stand-alone instruments, plug-in cards, cabled computer peripherals, and embedded in systems. Such systems are often designed with separate ADCs, DACs, and digital I/O devices. Many microcontrollers include ADCs and DACs, but that locks you into using that device. The AD5592R from Analog Devices combines all of these I/O functions, letting you use one chip to design measurement-and-control functions into systems.

A data-acquisition system on a chip – [Link]

Does your op amp oscillate?

BH Figure 1cx600

 

by Barry Harvey @ edn.com:

We analog designers take great pains to make our amplifiers stable when we design them, but there are many situations that cause them to oscillate in the real world. Various types of loads can make them sing. Improperly designed feedback networks can cause instability. Insufficient supply bypassing can offend. Finally, inputs and outputs can oscillate by themselves as one-port systems. This article will address common causes of oscillation and their remedies.

Does your op amp oscillate? – [Link]

Fast analog isolation with linear optocouplers

AnalogIsof1

by Avago Technologies:

Analog isolation is still widely used in motor drives, power monitoring, etc whereby applications typically use inexpensive analog voltage control for speed, intensity or other adjustments.

The HCNR201/200 analog optocoupler is commonly added to isolate the analog signal in the front end module of an application circuitry. The optocoupler will be placed between the analog input and the A/D converter to provide isolation of the analog input from the mixed signal ADC and other digital circuitries. The HCNR201/200 is an excellent solution for many of the analog isolation problems.

Fast analog isolation with linear optocouplers – [Link]

Auto-ranging Analog Voltmeter for a variable power supply

w2aew @ youtube.com writes:

This video describes and demonstrates a fun little circuit that is designed to create a automatically switching, dual-range analog voltmeter which is intended to be built into a variable power supply. By using two ranges, it permits accurately setting a low voltage such as 3.3 or 5V, as well as accurately setting a higher voltage like 24V. Setting a low voltage using a high voltage meter is not very precise, hence the reason I put this together. The circuit is demonstrated, and the schematic is reviewed to describe the operation.

Of course, there are many ways this can be done – this is just one example. It uses one of my favorite little analog ICs, the LM10 op amp and reference. The LM10 (designed by the legendary Bob Widlar) is used as a voltage reference and comparator with hysteresis. A zener diode is used as a shunt regulator. There’s an indicator LED to show when the meter is in the high range, and a 2N7000 enhancement mode n-channel MOSFET is used to change the resistors associated with the analog meter.

Auto-ranging Analog Voltmeter for a variable power supply – [Link]