UAD215A106 3BHE026284R0106 | ABB Adapter board

Description

A/D converter
Analog-to-digital Converter, referred to as A/D converter or ADC (Analog to Digital Converter), belongs to the forward channel device, the function is to convert analog signals into digital signals, which is convenient for later digital devices to process.

Analog-to-digital converter: The role of A/D conversion is to convert the analog signal with continuous time and amplitude into a digital signal with discrete time and amplitude. A/D conversion generally goes through four processes: sampling, retention, quantization and coding. In practical circuits, sampling and holding, quantization and coding are often synchronized.

Step 1 Classify

Several commonly used types include: integral type, successive approximation type, parallel comparison type/series parallel type, ∑-Δ modulation type, capacitor array successive comparison type, and voltage-frequency transformation type.

1) Integral type (such as TLC7135)
The integrated A/D works by converting the input voltage into time (pulse width signal) or frequency (pulse frequency), which is then obtained by the timer/counter with a digital value. The advantage is that high resolution can be obtained with a simple circuit, but the disadvantage is that the conversion rate is extremely low because the conversion accuracy depends on the integration time. Most of the early monolithic A/D converters used the integral type, and now the sequential comparison type has gradually become the mainstream.

Dual-integrated A/D converter: Converts the input voltage into a time signal or a frequency signal, and obtains the value through timers and counters. Because the converter integrates the input analog signal and the reference voltage signal twice, it is called A double-integrated A/D converter. Its advantage is that it can obtain high resolution with a simple circuit, but its disadvantage is that the conversion accuracy depends on the integration time, and the conversion rate is very low. The TLC7135 is A dual-integral A/D converter.

2) Successive comparison type (such as TLC0831)
Sequential comparison type A/D: consists of A comparator and D/A converter through sequential comparison logic, starting from MSB, sequentially compares the input voltage of each bit with the output of the built-in D/A converter, and outputs the digital value after n comparisons. The circuit size is medium. The advantages are high speed, low power consumption, cheap at low resolution (<12 bit), but high price at high precision (>12 bit). TLC0831 is A sequential comparison type A/D converter.

3) Parallel comparison/string parallel comparison (such as TLC5510)
Parallel comparison type A/D converter, using multiple comparators, only for one comparison and conversion, also known as FLash(fast) type. Due to the extremely high conversion rate, n-bit conversion is required

A comparator, so the circuit scale will be very large, the price is high, only suitable for video A/D converter and other particularly high speed fields.
Series parallel comparison type A/D: The structure is between the parallel type and the successive comparison type, the most typical is composed of two n/ 2-bit parallel AD converter, and then AD /A converter, with two comparisons to convert, so it is called Half flash(half fast) type.

There are also three - or multi-step implementations of A/D called Multistep/Subrangling A/D, and Pipelined A/D for conversion timing purposes. Modern angling A/D also incorporates features such as the ability to digitally correct the results of multiple conversions. This kind of A/D speed is higher than the successive comparison type, and the circuit scale is smaller than the parallel type.

4) ∑-Δ(Sigma/delta) modulation type (e.g. AD7705)
∑-Δ type A/D is composed of integrator, comparator, 1-bit D/A converter and digital filter. In principle, the input voltage is converted into a time (pulse width) signal, and the digital value is obtained after processing with a digital filter. The digital part of the circuit is basically easy to monolithic, and therefore easy to achieve high resolution. Mainly used for audio and measurement.

5) Capacitor array successive comparison type
Capacitor array sequential comparison type A/D: The capacitor matrix mode is used in the built-in D/A converter, which can also be called charge redistribution type. The value of most resistors in A general resistance array D/A converter must be consistent, and it is not easy to generate high-precision resistors on a single chip. If capacitance arrays are used instead of resistance arrays, high precision monolithic A/D converters can be made at low cost. Most recent successive comparison A/D converters are capacitor arrays.

6) Voltage frequency conversion type (such as AD650)
Voltage-Frequency Converter (voltage-frequency Converter) is an indirect conversion method to achieve analog-to-digital conversion. The principle is to first convert the input analog signal into a frequency, and then convert the frequency int

The company focuses on DCS, PLC, robot, large servo four systems

The main products are various modules/cards, controllers, touch screens, servo drivers Company advantage: Supply imported original products, professional production of spare parts One year warranty, fast delivery time, complete supply !！！ ① 24 hours email response (12 hours); ② For shipment outside Asia, please contact the seller.

ABB Related Products

【 Disclaimer 】 We sell new products and discontinued products, independent channels to buy such special products. Guizhou Yuanmiao Automation Equipment Co., Ltd. is not an authorized distributor, dealer or representative of the products featured on this website. All product names/product images, trademarks, brands and microlabels used on this Website are the property of their respective owners. Descriptions, depictions or sales of products with such names/images, trademarks, brands and logos are for identification purposes only and do not imply any association or authorization with any rights holder. This article is from the official website of Guizhou Yuanmiao Automation Equipment Co., LTD. Please attach this link:http://www.ymdcs.com/ABB/