Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [current-sink]

An electronic component that sinks current (current flows into it). Ideally, a current sink has infinite output impedance and sinks current independently of the voltage across it. Real implementations have high but not infinite output impedance and limited voltage ranges. See also the current-source tag.

An electronic component that sinks current (current flows into it). Ideally, a current sink has infinite output impedance and sinks current independently of the voltage across it. Real implementations have high but not infinite output impedance and limited voltage ranges. See also .

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Understanding 74LVC245 datasheet and current source/sink

I'm using a SN74LVC245A (datasheet) to shift 5V TTL down to 3.3V so I can read the signals with a Raspberry Pi. However I am getting really weird results (a 60Hz input signal is picked up by the Pi at anything between 110Hz and 320Hz) and I'm really…
Malvineous
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Current source with MOSFET

In the circuits below, what does the 100R resistor do? In my understanding the 1K along with the 200 pF create an integrator topology to provide some stability but how about the 100R that feeds the gate of the MOSFET? What does it do? Wouldn't that…
MrBit
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Sinking and Sourcing Current to and from a PIC24F Output Pin

Sinking and sourcing current refers to current going into and out of the MCU (respectively), right? If you configure a GPIO pin as an output, why would current ever go into the pin (since it's configured as an OUTPUT)? I suppose it depends what the…
The_Ders
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microamp constant current sink

I'm trying to put together a constant current sink circuit for discharging small Lithium-Ion coin cells. I need to be able to sink from about 200 uA to 12 mA. My first thought was to use some voltage regulators like the LM317 or the LP2951.…
jkrbasu
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How do I build the current regulator circuit referred to on the LM337 datasheet?

What I would like to accomplish: I am trying to add current regulators into a home built dual rail linear regulated power supply. I previously asked this question about transformer fusing and received useful responses from the EE Community. The…
Dave Guenther
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How to build a voltage-controlled current sink / voltage-controlled resistor

I am trying to control a current through several current-mirror device (specifically the IREF pin on the TLC5940) using a single potentiometer. I've tried using a modified Howland current souce as in the following schematic: simulate this circuit…
angelatlarge
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Why do PNP transistors source current and NPN transistors sink it?

I'm unable to find a definitive answer to this (trust me, I've looked, unless it's right under my snout) so please do point out the correct answer if I have. I'll feel foolish but at least then I'll know! This isn't about mirrors, etc. but more…
Marc Draco
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LiPo charging circuit to supply 1mA peak current, to charge a custom 1mAh LiPo cell

I am searching for a schematic or design that would help me charge a very small 1mAh 3.7V LiPo battery. I've done a pretty thorough search and the closest off-the-shelf IC I can find provides 10mA minimum current. My LiPo is only rated for 0.5C-1C…
exitfailure
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Power supply add-on to sink current

I have 10A lab PSUs at work of which most don't support sinking current (they shut down on overvoltage). The sinking time I need is typically very short: a few A for less than 1 second, the time it takes to dissipate energy stored in inductive parts…
Dmitry Grigoryev
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Increase 74LS TTL gate's output current to drive multiple high-power LEDs

If have several 1 watt LEDs that I want to drive off of a TTL gate's ouput. What can I do to increase a 74LS TTL logic chip's output fan-out (current) to be able to produce a true 5 V output that is capable of driving as much as 500 mA (or more if…
Michael Goldshteyn
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Are all voltage reference ICs able to sink as well as source current?

I'm looking at the REF30xx series of precision voltage references from TI. The datasheet lists a maximum output current of 25mA. Every specification and figure on the datasheet (e.g. load regulation on pages 3 and 5) shows only positive output…
Ben Voigt
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Low-side gate driver consistently shorts VDD to GND upon circuit power-up

I am using the UCC27423DGN dual low-side MOSFET driver as a current sink in order to drive some piezo elements. In general the gate drivers I am using are inverted, so on a high pulse on the Pulse_A/B lines, the outputs Pulse_A/B_Out should drop…
md-raz
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Using MOSFET as a voltage controlled current source

I am trying to make an electronic component that will do the following: Vc is the control voltage, it can change the current thru the device. I need Vx independent of the the current, that means current is fixed whatever the Vx is. How should I do…
kintaro
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FET based "zener amplifiers"

About the following circuit: *source: https://youtu.be/niZizzHBanA?t=1779 It is described as a negative power supply, where R1, R2, Q1 and Q2 form a current sink and Q3 "amplifies" the zener voltage, keeping a stable voltage between its drain (GND)…
tfm
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~40 uA current sink... what current mirror topology to use?

I need to sink a constant 20-60 microamps from the inverting input terminal of an op-amp in order to shift the output voltage upwards a bit. This is a pretty low-speed circuit, with little spectral power above 2 MHz. The feedback resistor I'm using…
Zane Kaminski
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