Skip to main content

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.

Filter by
Sorted by
Tagged with
0 votes
1 answer
57 views

Stability of a constant current sink( opamp+nmos)

I am using opamp and a mosfet as constant current source. My current is from 0mA to 25mA. Opamp-TLV9002 (GBW-1Mhz at 5v , phase margin - 78deg at 5.5v and gain as 1 ) Mosfet- nmos- Bss123lt1g ( input ...
funtastic rdj's user avatar
0 votes
1 answer
101 views

PSPICE non sinking voltage source

In an ideal world, most power supplies have a current sourcing feature but not a sinking feature. In this circuit, you can see that the 15V supply is sinking current. How can I prevent this in Pspice?
Electronx's user avatar
  • 756
2 votes
3 answers
268 views

Can someone explain this current sink circuit for me?

I am trying to get my head around this (current sink) circuit. I have seen this circuit with two NPN transistors and connected base - but to swap around one of them seems a little strange to me. Does ...
huababua's user avatar
  • 115
0 votes
3 answers
915 views

"Source", "sink" or both?

Having solved the mystery of "pulling" and "pushing" devices, it would be interesting to do the same with "sourcing" and "sinking" devices. Background A ...
Circuit fantasist's user avatar
3 votes
1 answer
259 views

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 ...
md-raz's user avatar
  • 50
0 votes
1 answer
211 views

How much soil does it take to make a viable earth ground?

My device lives in the soil, in a flower pot, or other garden container. It is about 16" long, has a 40-50mm diameter and runs on 5VDC. My question, how much soil does it take to develop a viable ...
Tim Cerka's user avatar
  • 109
1 vote
2 answers
102 views

What is the reason for observing a wiper voltage greater than the A and B PIN of a digital potentiometer?

I am working on a project to implement a variable resistance for high voltage circuit using a MOSFET current sink. The complete circuit is available here. I am sharing the first page of the circuit ...
SKGadi's user avatar
  • 862
4 votes
3 answers
2k views

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 ...
kintaro's user avatar
  • 347
-1 votes
1 answer
163 views

How does the attack / release element of this audio compressor function?

This is an audio compressor circuit based on (and designed by the makers of) the THAT 4301. U2B converts the AC input to RMS, which is then inverted by U2D. When there is no signal input to the ...
Josh Taylor's user avatar
1 vote
2 answers
162 views

I made this current sink to discharge a 9 V battery. Is this okay?

I would like to create charts. Voltage as a function of time. I want to do this to test models of different battery manufacturers. I want to see which battery contains the most Ah. I have done some ...
Daniel's user avatar
  • 333
0 votes
1 answer
1k views

Calculating capacitor discharge time with constant current sink

To calculate capacitor discharge time the formula is: But because the current being sink from the capacitor is constant from highest voltage to zero volt, I think the capacitor should discharge ...
ElectronSurf's user avatar
  • 2,396
0 votes
1 answer
278 views

LED driver resistors

I'm designing a circuit using an LED driver that is intended for RGB LEDs and uses a resistor to set the current for the constant current supply. On the LED datasheet, each color is tested at ...
usman510's user avatar
1 vote
0 answers
143 views

ESP32 bootstrap pins power consumption

The other day, I tried that connect to GPIO15 and GPIO5 GND with 26.7 kohm pull down resistor despite having a internal pull-up beacuse of IO obligation. I had no problems during a booting. Please ...
FAFİ's user avatar
  • 51
1 vote
2 answers
291 views

Supply voltage for opamp in a current sink circuit

I want to use an opamp in a current sink configuration in order to control the emitter-base current of a PNP transistor via a digital-analog pin from a microcontroller. The circuit is as shown below. ...
Martin Hepp's user avatar
6 votes
3 answers
3k views

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 ...
MrBit's user avatar
  • 2,053
2 votes
1 answer
100 views

Unwanted spike in the current sink circuit

I designed (with help of several online/offline resources) the following current sink circuit with features: Should be capable of sinking a maximum of 200 mA (AC, RMS). Follows the input sine wave <...
SKGadi's user avatar
  • 862
6 votes
3 answers
3k views

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 ...
Marc Draco's user avatar
2 votes
2 answers
423 views

Problems with over/undershoot in voltage-controlled MOSFET current sink

I'm in the process of designing an electronic load for testing batteries. The goal is to control the load current in the range of 0 - 10 A with a 0 - 1.2 V signal from a DAC. For easy calculations and ...
MMaz's user avatar
  • 23
1 vote
3 answers
1k views

Op-amp as a current sink

With no application in my mind, I am playing around the circuits and came up with some doubts. I asked a question in Current sinking in a DC-DC module to which I received the answer. However, I got ...
SKGadi's user avatar
  • 862
0 votes
4 answers
877 views

Current sinking in a DC-DC module

If I connect two DC-DC Modules (example module in the figure below) in parallel, can I increase its current capacity? Also, I have another doubt out of curiosity. If I connect a module in the ...
SKGadi's user avatar
  • 862
2 votes
1 answer
102 views

How to wire two open-drain logic outputs to a three pin bi-color LED

I am very new to working with electronics; my main experience is in programming. I am working on a project and intend to use this MCP73833/4 Li-Ion Charger. It has two "Charge Status Output" ...
Dan's user avatar
  • 123
0 votes
3 answers
364 views

Finding maximum sink and source currents from datasheet

How can I find the maximum sinking and sourcing currents of different pins in a microcontroller (namely 8051) from its datasheet? Edit: I have downloaded and looked at the datasheet, I just can't read ...
Amir Soleimani's user avatar
0 votes
2 answers
206 views

LED driver does not give constant current with a load

I'm working with an AL5810Q, which is a linear LED driver where the current can be set with only one external resistor following $$I_{LED}=\frac{750}{R_{SET}}.$$ With that, since I need a current of ...
Smart_Celery's user avatar
0 votes
1 answer
89 views

Regarding boost converter and current sink IC operation

I have a doubt regarding the use of a boost converter and a current sink. This doubt arises based on the following -very simplified- circuit. Following the attached circuit, the boost will take the ...
Smart_Celery's user avatar
1 vote
0 answers
83 views

USB VBus Current Shaping

I'm trying to solve a design issue regarding a USB device under development. The unit is quite similar to the TS-80P in that it implements Power Delivery and the main function is heating. We require ...
Dzarda's user avatar
  • 3,060
0 votes
1 answer
163 views

Explanation of filter for op amp controlled MOSFET current sink [closed]

I have designed this circuit and someone suggested R and C to enhance the functionality of the circuit. The circuit is basically a current controlled device. Depending on the voltage set by the ...
Ryan Pace's user avatar
0 votes
2 answers
262 views

What components are inside a port expander, how does it work? (Are they tiny MOSFETs?)

Do port expanders use MOSFETS internally to switch the pins high/low? My project is using a Raspberry Pi and a MCP 23017 port expander to sink some current (to GND through the port expander) from a ...
BetweenBeltSizes95's user avatar
2 votes
3 answers
163 views

What can I do to get a stable bias on this current sink?

I am still working on trying to get a stable 60 Hz ramp generator with a down-slope, and I am trying to do it from first principles and as simple as possible to understand fully what I'm doing. I got ...
Gunther Schadow's user avatar
4 votes
5 answers
393 views

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 ...
exitfailure's user avatar
4 votes
3 answers
1k views

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 ...
Dmitry Grigoryev's user avatar
0 votes
3 answers
110 views

Built difference amplifier "tail" vs. SPICE models

I am working on a difference amplifier example lab 5L.1 from Art Of Electronics Hands on Lab Course (I am not a student). I simulated three types of "tail" circuits using SPICE. Then I built ...
vgeng's user avatar
  • 49
3 votes
1 answer
387 views

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,...
tfm's user avatar
  • 439
1 vote
1 answer
193 views

How to sink more current than specified?

I am using the TLC5940 (datasheet) in an upcoming project to control the cathode side of an LED matrix, but each of my LEDs needs ...
Jared Cohen's user avatar
0 votes
3 answers
3k views

Constant current sink circuit for battery load simulating, microamp current draw

I need to create a constant current sink circuit such that I can simulate current draws from a battery, and analyze the battery behavior. I'll be testing a battery that is 3.1V with 12mAh capacity. I ...
exitfailure's user avatar
0 votes
0 answers
62 views

Is it possible to share a speaker line as ground?

Given the following circuit, how can I use terminal 3 to detect when the button has been pushed? Everything right of the 3 pin terminal is a manufactured device- the Aiphone LE-D. (Also note it's ...
Michael Ambrose's user avatar
1 vote
1 answer
528 views

Led Matrix multiplexing: sinking/sourcing current + LED brightness

I am trying to make an 8x8 LED matrix (actually a bigger one, but for now it would be easier to discuss this more simplified version) and I have gotten too confused about a few things concerning the ...
tsambou's user avatar
  • 13
0 votes
1 answer
94 views

GPIO Button setup with switching power supply

I have a small board with 8 GPIO's, I previously had 4 buttons connected thus used 4 as inputs and 4 as outputs. I use a 10k pull-down resistor for each button. I don't have a resister pre input to ...
chip's user avatar
  • 143
1 vote
0 answers
66 views

Why hasn't the industry standardized sink/source according to sensor/plc component type?

I know quite enough to understand how sink/source works when connecting sensors and PLCs, as well as how it works concerning the electronics components and circuit diagrams. What I don't understand is ...
Phill Donn's user avatar
1 vote
1 answer
199 views

Understanding current sourcing and sinking in TL2426 rail splitter

I have a 40dB active bandpass filter being powered off a single rail power supply with the TL2426 providing a virtual ground so I can get a dual power supply configuration. Currently, I'm having ...
MaskedAfrican's user avatar
1 vote
2 answers
1k views

I2C max pull-up resistors and current sink

I design a system with several devices connected to 400kHz I2C interface with wires. For now, I get shark fins instead of square waves, so I decrease pull up resistors value. The MCU, which drives ...
Roman Simonyan's user avatar
0 votes
1 answer
115 views

Switchable Multiple Channel Current Sink

I want to create a multiple Channel Current Sink which is switchable. I already have 2 designs, but i am not realy happy with both of them. Maybe some of you guys have a Idea how to improve one or a ...
Valentin Huppertz's user avatar
0 votes
0 answers
119 views

How to drive NFET with current sink (LP5569)?

I have a circuit where LP55231 is driving NFET and the load is a LED. It's working fine. Now I need to switch LP55231 to LP5569. The difference is that LP55231 PWM output is current source and LP5569 ...
tipo1000's user avatar
1 vote
1 answer
705 views

Stability Current Sink

I’m currently trying to create a programmable current sink. And I’m still trying to build up my circuit and searching for new parts. As I was searching for a OPA, I encountered much information about ...
Valentin Huppertz's user avatar
-1 votes
1 answer
2k views

STM32F Current sinking to I/O pin with 5V Vcc

I'm working with Nucleo-F411RE, which has a STM32F411RET6 uC. In the datasheet, the document says Vin for FT or TC pins will have maximum of Vdd + 4.0. Generally the uC uses Vdd = 3.3V then I ...
Chanho Jeon's user avatar
0 votes
2 answers
107 views

Why are the pins of an UDN2981 related?

This question is related to this question: udn2981-maximum-output-current-too-less. In the UDN2981 datasheet, the picture below shows the maximum current (page 14, bottom left picture). Since if I ...
Michel Keijzers's user avatar
0 votes
3 answers
390 views

MAX485 Receive Output pin current sufficient for optocoupler LED?

I want to recreate a project found at this link where an optocoupler's LED is a driven by the receiver output of a MAX485. Now, my question is, the LED series resistor (R5) value is 470ohms, if my ...
J. Doe's user avatar
  • 3
1 vote
2 answers
329 views

current sink/source in ADS114S06B analog/digital converter

Here is the datasheet. It seems from the graphs on page 17 that the I/O pins will sink or source as much as 7.5 mA: However on page 9 the table indicates an expected sourcing of 1 mA (I say expected ...
kellogs's user avatar
  • 1,061
0 votes
2 answers
78 views

Current drawn by a motor driver

Only interested in the binary logic part, not the motor side. The datasheet specifies a few absolute max ratings: Table 4. Absolute maximum rating IIN Input current (INA and INB pins) +/...
kellogs's user avatar
  • 1,061
2 votes
1 answer
7k views

Current source with op amp and transistor

I'm building current source with OP AMP LM358 and MOSFET transistor IRF5305. Here's schematic diagram of the circuit: I have two questions about it: 1) Maximal gate-source voltage of IRF5305 is +/-...
proffessor's user avatar
1 vote
1 answer
475 views

Testing regulated power supply: 100 mA current sink

Disclaimer: I'm trying to learn about circuits on my own. I'm reading as much as possible to avoid any basic mistakes, but if there's any, please point it out and I'll investigate further in that ...
clearscreen's user avatar