Dual Digital Pot 100K 雙路數位電位器 / 數位可變電阻

描述

Dual Digital Pot 100K 雙路數位電位器 / 數位可變電阻

數位電位器Digital Potentiometer（簡稱Digital Pot）是一種可以通過Arduino等微控制器程式設計控制，動態地改變阻值的CMOS模數混合積體電路。與傳統機械式電位器相比，數位電位器具有使用靈活（程式設計控制）、體積小（晶片）、可靠性高（沒有機械部件）等顯著優點，可在多種應用場景代替傳統機械電位器。數位電位器常用於音訊播放設備的程式控制音量調節中，如智慧音箱、手機、音樂播放機中的音量調節。

此外，如果配合運算放大器，數位電位器還可以用於動態改變電路的主要參數，如：LED直流調光（輸出電流）、線性穩壓電源（輸出電壓）、振盪器（頻率和振幅）、低通濾波器（頻寬）和差分放大器（增益）等應用場景中。

Dual Digital Pot 100K 雙路數位電位器 模組使用MCP42100 100K雙路數位電位器，寬供電電壓（DC 2.7V-5.5V），相容目前絕大部分微控制器的3.3V或5V供電，帶有兩路可獨立工作的數位電位器POT0和POT1，256級電阻抽頭。該模組體積小（20.0mm*18.0mm），預留SO引腳（串列資料輸出），可將多個模組層級聯使用。配合I/O擴展板與所附送的5P多對一公對公杜邦線，可方便地與Arduino進行快速連接。

本模塊所採用的MCP42100集成了兩路數字電位器POT0和POT1分別對應兩組引腳A0、B0、W0和A1、B1、W1。與機械電位器類似，A、B兩端可看作一電阻的兩端，標稱電阻Rab=100K，W端作為中間抽頭，可以在A、B兩端當中256個均勻分佈的位置上變化，實現阻值的變化。Dual Digital Pot 100K 雙路數位電位器 上電時，兩路數字電位器的W端均在中間位置。

產品使用示意圖

從示波器可觀察到兩組相位相反的三角波信號。若將該信號放大觀察，可發現該三角波由很多階梯組成，每級階梯對應一個抽頭電阻W的位置，其寬度正好對應每次改變電位器的延時1ms,三角波上升半週期和下降半週期分別由256級階梯組成，因此整個三角波的周期為256*2=512ms。由此可見，兩路數字電位器可快速切換抽頭位置，穩定時間達到微秒級別。

 

特性

• 低功耗，體積小
• 雙路數字電位器
• 支持3.3V或5V電平

 

應用場景

• 音頻播放設備的音量/音調調節
• LCD直流亮度調節，對比度調節
• 可編程線性穩壓電源、濾波器或差分放大器

 

Dual Digital Pot 100K 雙路數位電位器 技術規格

• 工作電壓：2.7～5.5V DC
• 靜態工作電流：< 1 μA
• 端到端電阻：100 KΩ
• 分辨率：8位，256個電阻抽頭
• 電位器數量：2個
• 接口類型：SPI
• 工作溫度：-40℃～85℃
• 模塊尺寸：20.0mm*18.0mm

配送清單

• 雙路數字電位器（100K） x1
• 5Pin多對一公對公杜邦線 x1

DOCUMENTS

產品維基
更多文檔

Dual Digital Potentiometer (100K)

Digital potentiometer is also called “Digital Pot” in short. It is a kind of mixed signal IC, which is able to dynamically change the internal resistors through MCU like Arduino. It can be applied to applications such as LED DC dimming, linear stable voltage source, oscillator, low pass filter or differential amplifier.

This breakout employs MCP42100 internally manufactured with two individual 100K digital pot. It features as small dimension and low power consumption. With our tutorial and sample code provided, you can quickly apply this module to your project. Compared to the traditional mechanical potentiometer, the digital pot features as flexible (program control), small size (ICs) and high reliability (without mechanical parts). It can replace the tradition one in many applications. Digital pot is usually used to change the sound volume in audio devices, such as smart loudspeaker, cell phone, and music player.

Digital Potentiometer (100K)

In addition, with a proper design op-amp circuit, the digital pot can also be applied to change some key parameters of the circuit dynamically, such as LED DC dimming (output current), linear stable voltage source (output voltage), oscillator (frequency and amplitude), low pass filter (bandwidth) and differential amplifier (gain).This breakout employs MCP42100 internally manufactured with two individual 100K digital pot POT0 and POT1. Each pot has 256 taps with a resistor of 100KΩ. It supports wide voltage supply (DC 2.7V – 5.5V) compatible with MCU of 3.3V and 5V. The breakout features as small size (20.0mm*18.0mm) and reserves the SO pin for multiple breakouts being configured in daisy-chain connection. If you have a I/O shield in hand, this breakout can be easily connected to it with the attached 5 pin male to male cable.

Two triangular waves out of phase can be observed from the oscilloscope. If we zoom in a section of the wave, the triangular wave is actually made up of many steps. Each steps correspond to one wiper position. The width of the step is about 1ms, because the program delay for 1ms between every wiper changes. The upstairs half cycle and the downstairs half cycle consist of 256 steps each, therefore the period of the triangular wave is 256*2=512ms. The digital pot can quickly change the wiper position and the settling time can up to micro seconds (18μs, typical).