All Questions
9
questions
1
vote
2
answers
1k
views
Driving a 12-to-24 V P-channel MOSFET with TTL
I'd like to control up to 16 motorized valves with an ESP32. I'm using 74HCT595 shift registers (5 V outputs, 3.3 V input logic) to drive 12 V relays via NPN transistors. But the relays are pretty ...
- 50
2
votes
1
answer
666
views
BJT transistor max switching frequency vs FET in high frequency computer architecture
Why arent BJTs used with RISC architectures to produce very high speed relatively sparse CPUs? My understanding is that BJTs don't have the forward bias gate capacitance requirements of FETs which is ...
- 43
1
vote
1
answer
3k
views
Interfacing 24VDC output with 5V TTL input
I have a project which requires me to interface a 24VDC output module (PLC) with a rather outdated 5V TTL input module.
From the schematics of the old module I can draw the conclusion that it uses +...
- 13
1
vote
1
answer
289
views
What is the purpose of the Load transistor in a TTL Logic NOT gate?
My professor presented the NOT gate in the Transistor-Transistor logic as the following:
Where V is always 5Volts. The two symbols are MOSFETs N-type transistors. The first transistor (which is ...
- 133
1
vote
2
answers
412
views
How do I find resistor values for an LSTTL to ECL interface?
LSTTL is a 74LS10 three input NAND gate
ECL levels are -0.75 volts and -1.55 volts
Supply voltages are +5 volts and -5.2 volts
I am really not sure how to proceed with this. I've tried setting the ...
- 13
1
vote
5
answers
361
views
How to "shift" a logic LOW of 2,5 V to GND?
I'm trying to control a 24 V LED strip with a device that has its own control mechanism and PWM output. (The output PWM frequency is 1 kHz.) The device itself requires 5 V, and since it does not draw ...
- 71
2
votes
3
answers
4k
views
Switching 60V with 3.3V microcontroller at 50kHz - 1MHz
I'm playing around with some switching mode power supply things. For this reason, I'd like to switch the input voltage with a microcontroller, from the PWM output or other output pins.
The specifics:
...
- 444
1
vote
1
answer
2k
views
Optimal method for multiple MOSFETs for LED driving with a shared power rail
I have three LEDs (RGB), with the following forward voltages and current:
red 2.25 V @ 0.35 A
green 3.3 V @ 0.35 A
blue 3.1V @ 0.35 A
I plan on using three (3) RFP30N06LE MOSFETs in parallel @ 0.35 ...
- 11
13
votes
1
answer
4k
views
How is this circuit for level converting (5V<>3.3V) working?
Does anybody know, how is this circuit exactly working? It is level converter between 5V and 3.3V logic and it is bi-directional.
I have some theory, but I am not sure with it (I never worked with ...
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