All Questions
Tagged with logic-level cmos
16
questions
0
votes
2
answers
336
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Fast unidirectional level switch from 5 V to 3.3 V
I came up with this circuit. Is it good or bad to use diodes? In my opinion, this is better than a divider or a FET, at least faster, as you can see from the waveforms. Will such a circuit create ...
- 3
1
vote
1
answer
2k
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What are the output logic levels of this STM32?
I am struggling getting my head around the input and output logic levels, mostly the output levels of this STM32 (STM32F446xC/E).
This table shows the output logic levels as dependent on if it is a ...
- 161
0
votes
1
answer
261
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5V to 3.3V Converter
I have a problem in connecting Raspberry PI to an MCP3202. I am using MCP3202 at 5V and knowing that raspberry pi works on 3.3v. I have found a solution to convert from 3.3V to 5V using 74HCT244.
And ...
0
votes
2
answers
124
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Are D flipflop inputs and clock thresholds the same for a given logic family?
I'm using an SOIC20 74ACT574 octal flipflop in a design.
Vcc is 5 V, and GND is 0 V. The datasheets give V_IH (logic high input, guaranteed minimum) as 2.0 V and V_IL (logic low input, guaranteed ...
- 1,104
1
vote
4
answers
758
views
Shifting a 2.7V digital signal to Arduino logical levels?
I'm pretty much a beginner in electronics and I'm currently working on a personal project, where I have a device, that is putting out a digital signal (square wave) that goes from 0V - 2.7V and I need ...
- 109
2
votes
1
answer
147
views
Can a Z84C00 CPU directly drive 74HCxxx series logic?
I'm getting confused by the datasheet for the Z84C00 CPU, while trying to work out if I can use it to drive 74HCxxx chips, or if I need TTL-compatible logic (i.e. either 74HCTxxx or 74LSxxx). It's ...
- 2,046
0
votes
1
answer
432
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How can I have an ECL logic input for a CMOS logic gate
I'm working on a triggering system that uses a comparator to check if the signal is below a threshold value. I found a great comparator for the job, except its output is ECL logic. I wanted to use the ...
- 23
9
votes
2
answers
8k
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Fast bidirectional 3.3 to 5V level shifter
For a hobby project of mine, I'm thinking about connecting some old 5V SRAM chips like this one to a 3.3V - capable FPGA. The target frequency is 50MHz. After some simulator experiments I found out ...
- 25.9k
0
votes
1
answer
864
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How can I raise a CMOS 1.8V output to 5V LVTTL input with a MOSFET?
simulate this circuit – Schematic created using CircuitLab
I'm trying to drive a 5V LVTTL UART input on a ATMega32u4 with a 1.8V CMOS ouput on a Telit UL865. I'm using the NTE2987 enhancement ...
- 181
1
vote
2
answers
161
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Why is Vtyp less than Vmin on a CMOS chip
Regarding the chip 74HC08
On the table describing Static Characteristics (Section 9). Why is the typical VIH lower than the minimum value.
And vice versa for VIL
- 182
0
votes
3
answers
161
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CMOS Logic system
When I was practicing logic circuit design using PMOS and NMOS, it's said that we have to use all PMOS for Pull Up Network (PUN) and NMOS for Pull Down Network (PDN). But, we know that for input ...
- 1,176
2
votes
1
answer
2k
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Combining CMOS and TTL logic
I have a bunch of 74LS383 (TTL octal transparent latch with three-state outputs) and MM74C83N (CMOS 4-bit binary full adder) that I would like to connect together. I need to connect the output of the ...
user17592
1
vote
3
answers
5k
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Circuit to switch about 5W of 12V using CMOS logic inputs using N-channel MOSFET?
I want to switch some 12V landscape light LEDs, totaling about 5 watts, using MOSFETs, with the control signal provided by a digital output line from an Arduino microcontroller running at 5V.
I ...
- 1,418
11
votes
4
answers
4k
views
Should I use CMOS vs. TTL?
Now, I know that this question has been asked so many times that it seems like I'm trolling, but I must point out that I couldn't find the right answer to this question anywhere.
So yeah, CMOS and ...
- 1,947
3
votes
1
answer
242
views
making sense of HCT ACT cmos "addional supply current"
I'm trying to make a low-current level shifter from low voltage (~2V) CMOS up to 5V CMOS.
I had the idea to use TTL-compatible CMOS gates in the HCT or ACT families.
But this line in the 74HCT04 ...
- 20k