Questions tagged [nand]
Use this tag when referring to any circuit that uses NAND gate / NAND logic, or for asking questions relating to NAND gates.
111
questions
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1answer
51 views
Wear leveling and supply of voltage
Does anyone know if a NAND flash device (e.g. microSD) has to be continuously supplied with energy for its wear leveling algorithms work as designed? Or, if it doesn't matter if the device is (safely) ...
0
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0answers
49 views
File system to use with NAND Flash and 32 bit microcontroller
I am searching for a file system, suitable for NAND flash memory chips.
Currently I use a Micron 256MB SPI NAND flash memory where I write and read raw sensors data but without a file system and ...
0
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1answer
43 views
Can't read an entire page at once (NAND flash)
I am working for quite a while now with a GD5F1GQ4UCYIG from GigaDevice. The goal is to dump the content of the flash.
To do so I use a BusPirate. The NAND flash itself is still attached to the board,...
1
vote
1answer
76 views
TTL Logic Gate Resistor Values
I've been teaching myself the basics of circuits for the last few months and have been enjoying going into chip schematics. I'm trying to understand why the resistor values are as they are. For ...
0
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1answer
42 views
Converting gates in XOR circuit to NAND gates
I have this XOR circuit:
I tried to write it using only NAND gates and this was the furthest I got:
According to my book, it should look like this:
I did this:
$$(x.y')+(x' . y) = ( (x. y')+(x' . y)...
1
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0answers
95 views
Is there a need for a third transistor in a NAND gate?
I was attempting to create my "own" NAND-gate S/R latch using NPN transistors (I know there are ICs available for that)
From my own knowledge of how transistors work, I came up with this circuit for ...
0
votes
1answer
39 views
User controlled storage devices existence
Today's memory devices have a lot of logic embedded before data is actually written onto the NAND pages.
An example could be wear levelling algorithm , FTL functionalities etc.
The typical life of a ...
0
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1answer
59 views
Why is there no race around condition in NOR SR latch when S=R=0(initially)?
When the IC gets connected to the Vcc+, both the NOR gates get the input 0 and 0 (low) which yields the output 1. Now since both the outputs are again connected as one of the input to each of the NOR ...
0
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1answer
61 views
Output on Pass-transistor NAND gate lower than expected
I have an assignment to design an IC NAND gate, consisting og 2 NMOS-transistors and a designed inverter as seen in figure 1 and 2.
But when measuring the output at Vout, we only get about 60% of the ...
0
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1answer
72 views
1 TTL IC -> inverter + 2-input NAND + 3-input NAND
I came across this question in my homework:
Implement the following gates using only one TTL IC: one inverter, one 2-input NAND and one 3-input NAND.
The type of IC they're talking about has 14 ...
0
votes
2answers
213 views
Can anyone help me to understand what these capacitors do in this design?
I have a circuit design makes a button latch on-off and drive a mosfet. When I energize the circuit Vout that drives thr mosfet is initially low.
After pressing the button, the button state changes ...
0
votes
1answer
72 views
Using NAND gates to construct OR/AND gates
I have this Boolean equation
B'*C'*D' + A*C*D + C*D*E'
and I was just wondering how to use nand gates to express this equation.
With the schematic the inputs are
NAND1 it is B'*C'*D'
NAND ...
0
votes
2answers
167 views
use minimum number of NAND gates to realize this boolean expression [closed]
How should I proceed to find the minimum number of 2 input NAND gates to realize this boolean expression. I am allowed to use both complemented and non-complemented inputs.
$$F = X.Y + Y.Z + \...
1
vote
1answer
63 views
CD4011BE (DUAL INPUT NAND GATE) not working
I am using my CD4011BE NAND Gate IC. I connected a 9V battery in the 14th pin. And grounded the 7th pin. Then I provided input in the first 2 pins. I took a 330 ohm resistor from the third pin and ...
0
votes
2answers
197 views
Is there an intuitive reason for why NAND gate is a universal gate?
Now I know the maths and logic to figure out that every boolean function can be expressed using only AND and NOT gates, which in turn can be expressed using only NAND gate and hence every boolean ...
0
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1answer
122 views
Problem with NAND gate in proteus
I was doing a simple logic circuit in proteus when i realised that something was going wrong.
It looks like the NAND gate provides high voltage to its inputs from nowhere. No errors provided, but if ...
0
votes
1answer
144 views
momentary switch latching circuit
I'm very new at all this and hope you will have patients with me, I'm trying to use this circuit diagram to turn a momentary switch into a latching switch, I though it would be straightforward but ...
0
votes
1answer
117 views
Which input of NAND is preferred and why? [duplicate]
Let A and B be two inputs of the NAND gate. Say input A arrives at the NAND gate later than input B. To optimize delay of the two series NMOS inputs A and B which one would you place near to the ...
0
votes
2answers
78 views
Negative pluse generator does not reach 0V
I'm using an Arduino board to generate a 125KHz square wave signal to feed into this curcuit:
simulate this circuit – Schematic created using CircuitLab
So this is what I'm receiving from my ...
0
votes
1answer
83 views
Identifying this logic gate
Could somebody please explain the two logic gates with only the one input, A and B, respectively??
It is a NAND gate, with a box just before it.
What is this box?
Why only one input?
4
votes
2answers
1k views
More Fun with the CD4093 IC as Schmitt Trigger Oscillator. Any practical difference between circuit version with “Enable” pin and Without?
I built two Schmitt trigger oscillator circuits using the CD4093BE IC from Texas Instruments. The CD4093 is a quad NAND gate with Schmitt trigger inputs.
You can find the datasheet here: http://www....
1
vote
0answers
98 views
Which pins are required when reading and writing NAND flash?
I plan on reading and probably writing NAND flash on some embedded devices or USB flash drives.
I did not come across many examples for in circuit reading though I'd give that a try at first if ...
2
votes
1answer
57 views
Simplifying logic circuit [closed]
I've been trying to simplify a combinational circuit and wanted to know whether there was any simpler way of solving such questions. Do we have to find all the outputs and such or we can use a simpler ...
0
votes
0answers
52 views
Implementing with only NOR gates [duplicate]
I have an equation
y = ab + cb'
How would I implement this with only NOR Gates?
Thanks
0
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1answer
266 views
Minimum number of NAND gates to implement f(x,y,z,w)=x(y+zw)+yz'
As the title states, given a function f(x,y,z,w)=x(y+zw)+yz', what are the minimum number of NAND gates you need to implement f?
My first attempt at a solution was to draw a kmap to see if there was ...
0
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0answers
66 views
Acquire a “TIC” signal from a power meter
I'm trying to acquire the tic signal of a french power meter.
From the datasheet available here of the TIC signal we can find out that the signal is (page 7/38): 6 Vrms +/- 10% at 50 kHz
It comes ...
1
vote
2answers
209 views
Can I lower flash power consumption by pre-flashing all values to high?
I am designing an embedded system that will use either embedded flash memory or an SD card.
The system must survive without much power and the estimated 30mA draw of an SD card sounds too high for me.
...
0
votes
1answer
45 views
NAND Simplified with xy + !x z
I've been trying to work on a few problems, though I'm not sure how to rewrite this a few circuits using only NAND/NOR -->
an example is shown below;
How am I able to rewrite only using NAND + NOR ...
-2
votes
3answers
76 views
Determination of read/write lifespans of NAND drives
I check around and there are various numbers for different manufacturers solid state drives as read and write life terms. At the very fundamental level input/output speeds of these devices are pretty ...
1
vote
1answer
134 views
How can i make f(a,b,c) = \$A \cdot B \cdot \overline C + A \cdot \overline B\cdot C\$ using only XORs and NANDs?
i have this problem where i need to make the Logical Function represented by :
f(A,B,C)= \$A \cdot B \cdot \overline C + A \cdot \overline B\cdot C\ \$ using only XORs and NANDs
The function was as ...
0
votes
1answer
80 views
How to know the size (W/L) for a circuit to source or sink a minimum of 4 times as much current as a minimum sized conventional inverter?
Consider the tri-state NAND below (i.e. if EN is high, output is NAND of A&B; if EN low, output is
floating. Assume EN and ~EN always track). Show work.
a) Label each transistor with a size which ...
0
votes
3answers
53 views
Low voltage form a NAND logic gate then the state is high
I've been trying to learn how to use logic gates. I wanted to use logic gate to bump digital signal from 3.3V MCU to a 5V. I took a T74LS38D1 and mocked the solution using two switches connected to 3....
0
votes
1answer
41 views
Implementing a simple logic equation
I need to do a lab that seemed like it was simple, but for some reason i cant get the right output for this function. its G(0)= T1T3'+T5T7'. These are data inputs.. I can only use NAND and NOR gates. ...
2
votes
0answers
78 views
MOSFET burn down due to droping logic level voltage [duplicate]
I made 2 PCB, one is a logic driver with NAND Schmitt trigger (74HC132D & CD40106B) to drive FORWARD and BACKWARD of H-bridge channel, the other board is the H-bridge Power MOSFET, which used 4 P ...
0
votes
1answer
298 views
H-bridge MOSFET NAND gate driver suffered from logic voltage drop
I've tried to reproduce the NAND Schmitt triggers circuit to drive my H-bridge MOSFET as per following source:
http://axotron.se/index_en.php?page=34&chapter=0
All my design files are at this ...
0
votes
2answers
2k views
How to extract data from an NAND chip with an NAND reader from iphone 6? [closed]
I am not an electrical engineer and I cannot take phones apart.
I had an iphone 6 that suffered no water damage, no smashed screens, no dust... but suddenly it got an NAND memory issue. The phone ...
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votes
1answer
179 views
TTL NAND logic circuit
how can find the maximum fan-out of the TTL-NAND gate using LTSpice ? i tried to solve problem by hand, but the problem how to find fan-out using ltspice
0
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2answers
119 views
CMOS NAND Image
I was looking at this image which shows a CMOS NAND standard cell.
However, how can I see this depicts a NAND?
A CMOS NAND has parallel PMOS and serial NMOS transistors but somehow I can't see this ...
0
votes
2answers
176 views
Momentary Switch NAND Latching IC Burning and (Possibly) Faulty Logic
Problem:
My issue is that the momentary switch with NAND latching logic that I have designed is not functioning consistently. It does work as intended at first, but then fails to work after repeated ...
1
vote
1answer
878 views
Latching Press-on / hold-off toggle switch circuit. Works on breadboard not on PCB
I followed a schematic and mocked up a Latching toggle switch with NAND gates. (see picture below for what I followed)
(Source)
I have mocked it up onto a breadboard. Using the exact same values of ...
0
votes
1answer
56 views
How can i simulate this circuit to match with the truth table?
How can I simulate this NAND logic circuit to match the truth table?]2
0
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0answers
61 views
Writing unused areas of a page on a NAND flash
I'm working on a project based on the ESP32 that uses a NAND chip from the GD5F1 family (link to the datasheet). Sorry for the long question, but it's a bit convoluted, and it's driving me nuts for ...
1
vote
2answers
294 views
nand gate astable vibrator do not work at 400kHz
I want to build a 400kHz square wave oscillator with NAND GATE using the CD4011BE circuit.
Unfortunately, it does not work as expected when I use R2 and C values according this schematic:
...
0
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1answer
56 views
Alternative for adder out of NAND-gates
Recently I was experimenting with the NAND-gate representation of an adder circuit and tried to implemenent it without crossing wires. So I got this:
The carry is negated, but when chaining two of ...
8
votes
5answers
3k views
Is the NAND logic gate perfectly symmetrical?
In other words: if we swap A and B, will Q behave exactly the same in DC and transient analysis?
0
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1answer
1k views
Current and Voltage in CMOS Logic Gate
So, in the NAND gate below, I understand how it works with the p-type and n-type transistors. However, my question is what happens with the current when the output is connected to Vdd? If the voltage ...
0
votes
2answers
202 views
NAND flash retention using USB charger?
NAND-based digital flash data storage devices such as SD,SSD,USBstick,eMMC,UFS,etc. do have transistors, where the small amount of electrical charge does slowly leak over time, resulting into data ...
0
votes
1answer
104 views
NAND technology - ecc error
Nand technology has some issues, which I find it a bit difficult to understand.
It is said in nand devices that manufacture guaranty that a page will have no more than X (4/8/16,etc according to nand ...
1
vote
1answer
76 views
Transforming logical circuit in NANDs and ORs [closed]
I can't transform this circuit in an exclusively NOR and another NAND circuit.
Everytime I tryed to simulate both circuits, neither of them gave me the correct result.
F=(notB)+AC
English is not my ...
0
votes
1answer
115 views
Circuit design using only NANDs and Inverters
So I'm having trouble with some circuit design for class.
We're given a truth table with 4 inputs and 2 outputs. I have karnaugh maps for the inputs and simplified my boolean expression. We have to ...
