Questions tagged [level-shifting]

Level shifting is the process of converting between different logic levels. E.g. from 0-3.3 V logic to 0-5 V logic

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2answers
724 views

Flipping a signal

I've an input of two input lines, one being connected to ground and one carrying the signal (measured to ground). The output should be three lines with one being ground and the others measured in ...
3
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2answers
3k views

1.8V to 5V, still not comfortable with transistors

I have a H-bridge IC L293DNE that needs 5V input signals to operate, however my available outputs are only 1.8V from a Gumstix Overo GPIO pin. I have a power supply that supplies me with +5V 1A. I've ...
7
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3answers
17k views

Level Shifting 1.8V to 5V with N-channel FET

I am using BeagleBoard-xM GPIO outputs to drive some DC motors with the help of L293D IC. The problem is that there is a difference between voltage levels. The GPIO outputs only supply 1.8V while ...
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1answer
2k views

Square Wave Voltage Level Shifting (Take 2)

After my question before, I tried to design a circuit with zener diodes and transistors for this issue. It seems to work in simulation. Am I overdoing it? Are there any other simpler ways to do this, ...
2
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2answers
765 views

Square Wave Voltage Level Shifting

I have a square wave signal of 300 KHz which is 0.2 V to 1 V. It is the output of FP5138 Non-Sync PWM Controller IC. I want to drive a PMOS with this square wave but with the levels shifted to (Vin-12)...
12
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1answer
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 ...
24
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1answer
22k views

Is my MOSFET-based bidirectional level shifter insane?

In a moment of cheapness, I decided not to order a 5v to 3.3v level shifter from Sparkfun, but instead to put it together myself. The original schematic used a BSS138 MOSFET, but since I enjoy ...
6
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3answers
11k views

Bidirectional level swiching 5V <-> 3.3V

I am looking to interface a 3.3V device with a 5V one. This will require the shifting of the logic levels between the two devices. Doing this in one direction is a trivial matter, but I need to do ...
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3answers
2k views

Level shift + amplify

Let's say I have a signal where 1v is digital 0, and 4v is digital 1. I am a little lost how can I use PNP+NPN transistor to have +11..12(for 1) or -11..12V(for 0) output, provided that I have +12/-...
9
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6answers
14k views

Increasing Voltage

I have a binary signal, 0V to 1.4V, which I can't change directly. What circuitry, (on a PCB) can I use to increase 1.4V to at least 2.5V. Do I need a transistor? I guess I'm looking for a switch ...
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3answers
881 views

Arduino Serial TX to iPhone RX voltage drop?

Articles I read about this tell me to hook up a 1KOhm resistor between the Arduino's TX and the iPhone's RX. I understand this is because Arduino's signal is 5V and I want 3.3V going to the iPhone. ...
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2answers
1k views

Logic Level Converter, Arduino and Cellphone

I am trying to interface a 6150 Nokia cellphone with an Arduino Duemilanove board, as some have already done through the FBUS protocol (see here for example). The FBUS protocol uses 2.8V logic, so I ...
8
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2answers
8k views

How do I get an Arduino (5 V) and MPR121 (3.3 V) to talk?

I have the Sparkfun MPR121 I2C Capacitive touch sensor breakout board I have read that it uses 3.3 V, I know that I can't just connect up the 3.3 V power supply output from the Arduino as the ...
2
votes
1answer
940 views

Shift 0-5V logic to ±2.5V logic

What's the simplest way at low speeds (sub 100 Hz) to shift 0-5V to ±2.5V? I was thinking of using a comparator or op-amp, but there must be a simpler / cheaper way. I wanted to avoid a dedicated chip,...
3
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3answers
11k views

How do I shift voltage levels?

I want to use an RF12B to communicate over radio with an Arduino, but the transceiver is rated at 3.3 V. I hear I need to use a voltage level shifter, but what do these look like and where can I ...
5
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2answers
679 views

How do I interface with OBD-II?

I've been tasked with interfacing with the on-board diagnostics of a vehicle. Some systems use 7V signalling, some use 5V signalling, some signal up to the battery voltage (which can be as high as ...
2
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3answers
1k views

I²C level shifter pulls low side up

I am using the well-known I²C level shifter from that appnote from Philips. The 3V side is supplied by an LP2950-3.0 regulator and is loaded only moderate (a few quite lazy 74's). The problem I'm ...
4
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3answers
4k views

Voltage level shifter

I need to make a voltage level shifter. It needs to translate a TTL logic level into a 12 V logic level. I have applied the 5 V at the base and 12 V Vcc and took the output from the ...