# Questions tagged [digital-logic]

Digital electronics treats discrete signals, unlike analog electronics that treat continuous signals. Digital logic is used to perform arithmetic operations with electric signals, and constitutes the base for building CPUs.

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### How to set a digital out to 24V Vcc

I want a curcuit with 3.3V and 24V supply. The micro will use the 3.3V supply, which needs to be able to set multiple industrial 24V digital outputs. My plan was a simple op amp, but as far as I know ...
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### Binary coded decimal ICs

Is there any IC that can be use to convert 9 bit binary code to seven segment display? EX: 100101100->300 I want to display 300 in seven segment display when 100101100 binary code applied to input.I ...
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1 vote
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### multi turn potentiometers to measure degrees

I want to display degrees in a seven segment display when rotate multi turn potentiometers.After rotating one round it should be reset to 0 degree.I can use A to D converter ICs.But how I give ...
• 87
9k views

### Creating a combination lock using logic gates?

I am trying to figure out how to create a combination lock using logic gates, so that a password must be input (let's say pressing numbered buttons) in the correct order. I understand logic gates ...
217 views

### System Generator: a block similar to a three state logic

does anyone what is the xilinx block for getting a three state logic?
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### How to convert an expression from SOP to POS and back in Boolean Algebra?

How to convert a Sum of Products (SOP) expression to Product of Sums (POS) form and vice versa in Boolean Algebra? e.g.: F = xy' + yz'
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### AGND/AVDD on a chip

I am considering using a chip, but the datasheet is confusing me as it has several distinct power pins. It has: PLL_VDD PLL_GND AVDD AGND DVDD DGND DVDD_IO DGND_IO This is the chip. How do I hook ...
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339 views

### Transmitting NTSC over digital link

I'm interested in capturing analog video in NTSC and transmitting it as efficiently as possible over a digital link, preferably while maintaining as much fidelity to the original signal as possible. ...
846 views

### Is there a free cross-platform tool for pure digital gate-level schematic design and simulation?

I'm searching a software tool for teaching purpose in order to teach students digital hardware (starting from logic gates level). Do you have something in mind that will allow making simple graphical ...
1k views

### What will happen if I send an analog signal through a digital regenerator?

What will happen if I send an analog signal through a digital regenerator?
10k views

### Logic circuit to handle incrementing by 1

You can use cascaded full adders to add any two binary numbers together. Is there a circuit for when I only want to add 1 (incrementing the value)? Is there a similar circuit for subtracting (i.e. ...
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14k views

### Book recommendations for digital circuit design? [closed]

not sure if "digital circuit design" is exactly what I'm aiming for, but someone can tell me and I'll edit it if another name matches better. Basically, circuit design interest me a lot. I like the ...
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### Why are things like RESET/MCLR active low on most ICs?

Convention? Easier to implement? Another reason? Is there a reason things like MCLR or RESET on microcontrollers are active-low, that is, you have to pull them down to reset the IC, and pull them ...
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### What precautions should I take when mixing analog audio and digital on the same board?

What precautions should I take when mixing analog audio and digital (uC control) on the same board? I don't want to hear the I2C bus in my speakers. I'm thinking about Separate power supplies ...
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926 views

### Is there a bidirectional level converter IC for multiple I/O channels?

I have two digital devices to connect, both use 20 data lines but one works at 3.3V and the other at 1.8V, and most of the lines are bidirectional. The operating frequency should be at least 5 MHz. I ...
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### CMOS (or CMOS compatible) shift register with latched open-drain outputs

I've been looking for a 3.3V compatible shift register (SIPO) with latched open-drain outputs. I've settled on a 74xx596 (not a '595!), but of all the 74xx CMOS series I've been looking at omit this ...
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985 views

### Using a digital potentiometer with a SMPS?

Is it possible to use a digital potentiometer with an SMPS, to adjust the voltage? I'm looking at one with a 2 MHz -3dB bandwidth. What does this mean for a 300 kHz switcher?
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52k views

### What is the difference between PLA and ROM?

I'm finding it hard to understand. What is the difference between PLA and ROM? Can somebody please provide a link or explanation?
3k views

### Most Simple Stoplight circuit

What would be the simplest way without using a microcontroller to make a stop light circuit. All it must do is go from Green -> Yellow -> Red.
8k views

### LED Quiz Buzzer Circuit With Logic Gates

I am very new to electronics. I am programmer and I've never done anything with electronics. However I started using simulators now. I want to make a simple quiz buzzer circuit With LED. e.g. I need ...
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62k views

### Make a momentary switch control a toggle

What are the simplest, cheapest, smallest ways to make a momentary switch produce a 2-state toggling output (latching momentary switch)? In other words, the output is continuously low, and when you ...
• 28k
361 views

### Bit/data stream unknown. How to figure out?

I have taken apart a digital weight scale and on the circuit are two pins labelled 'test'. When connecting this to the soundcard of my PC I can see it is a digital signal (high/lows), but I don't know ...
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518 views

### logical not circuit?

I don't have much experience with electronics, but I think what I want to do could be cobbled together from a Radioshack. I have a Dig 5006-IP automatic sprinkler controller. It controls 24V DC ...
716 views

### logic triggerable strobe light circuit

Does anyone have a circuit that will trigger a strobe light to flash in response to a TTL logic signal? Specifically, if I have a strobe circuit capable of flashing 1000 times per second, it seems ...
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### Beginner's logic analyzer?

Can anyone recommend a low cost or DIY buildable logic analyzer? Mostly, it would be for debugging serial protocols (SPI, I2C, RS232) at low voltages.