New SAR ADC family enables high-speed, high-resolution analogue-to-digital conversion in harsh environments

This is a submission from Microchip about 12 new Successive Approximation Register (SAR) Analogue-to-Digital Converters (ADCs) together with a companion differential amplifier designed specifically for the new portfolio of SAR ADCs.

I wrote previously that it is hard to pass the EXIT / AUSGANG gates at the embedded world trade show in Nuremberg and not have a few demo or dev kits in your sponsored rucksack. That’s why the show is a must-attend for serious electronicists of all ages. I consider myself one but this year I was unable to attend the show and what do you think, I still I received a kit — it simply arrived in the mail a few days later. It is the Otii Arc Demo kit from IoT developers Qoitech in Sweden hence the polar bear on the box. On the Arc box proper I saw “Sony Belgium” printed.

A new dual 14-bit A/D converter (ADC) designed to support communications applications capable of direct sampling wide bandwidth analog signals of up to 5 GHz has a ?3 dB bandwidth of 9 GHz. The ADC cores feature a multistage, differential pipelined architecture with integrated output error correction logic. The device’s inputs support a variety of user-selectable input ranges while an integrated voltage reference simplifies the use of the part.

A while back we made a little break-out-board with a ADS1115 A/D converter (140169-1). It has four inputs that can be used in a single-ended mode or two inputs can be used in a differential mode. A project still in development is a power meter for mains powered appliances.

A while back we made a little break-out-board with a ADS1115 A/D converter (140169-1). It has four inputs that can be used in a single-ended mode or two inputs can be used in a differential mode. A project still in development is a power meter for mains powered appliances.

The assembled module is available in our shop.

The assembled module is available in our shop.

Until not so long ago, only 8-bit analogue-to-digital converters (ADC) offered an I²C™ interface. Unfortunately, a resolution of 256 samples is inadequate for a number of measurements. The 12-bit ADC described in this short article has a resolution×16 or even ×64 as high. This makes it a lot more convenient to read, say, the usual temperature sensors, such as the LM335, which output 10 mV °C–1. With a 12-bit ADC and an internal reference voltage of 4.096 V, the resolution is 1 mV, which means that the sensor reading can be read in 0.1 °C. With an 8-bit converter, the resolution would be only 1.6 °C.

Together with a small program running under DOS, the circuit discussed in this article acts as an ADCbased voltmeter that allows you to calculate the capacity of a rechargeable battery. The PC also lends a helping hand by displaying graphs showing the instantaneous battery capacity and terminal voltage.

The Type MAX187 +5 V, low-power, 12-bit ADC (analogue-to-digital converter) chip from Maxim enables a PC to be provided with an analogue input via which analogue voltages may be measured with a high degree of accuracy. The interface designed for this is connected to the parallel printer port, so it can be used with all PCs, including laptops. Demonstration software (for Windows) available through our Readers Services makes getting acquainted with the interface a straightforward matter.