Talk:Charge pump

Charge pumps in PLLs
The article only mentions DC/DC conversion as an application for a CP. A different kind of CP is an important part of for example a PLL.

I came to this page looking for discussion of CP's for DC/DC conversion, so I would rather see it expounded on than merged with something else.


 * Your message does not have a signature or a date so it's unclear how old your comment is. Also, it's unclear what you want to see since a section that mentions charge pumps in PLLs is part of the article. I'm not sure what you mean to say with "expounded" and "merged with something else"


 * ICE77 (talk) 15:44, 19 August 2015 (UTC)

Neon signs
I'm fairly sure neon signs don't use charge pumps, but rather switch-mode power supplies. I have removed the statement as unreferenced. If anyone has a reference to such please link it. Evand 23:54, 28 May 2007 (UTC)


 * Are not charge pumps a form of switch-mode power supply? I would think articles on switch-mode power supplies and DC-DC power conversion should link here. But I am not an expert in this field. --Treekids (talk) 19:40, 11 December 2007 (UTC)


 * Yes, charge pumps are one kind of switch-mode power supply. However, a neon sign uses a neon sign transformer (which is technically not a switch-mode power supply) or a boost converter, a different kind of switch-mode power supply. I suppose it's possible to make a neon sign run from something like a charge pump, but at the high voltages necessary, most people would call it a voltage multiplier rather than a charge pump. --68.0.124.33 (talk) 02:45, 13 April 2009 (UTC)

Need a picture
We need a sample circuit here, and perhaps some scope traces. At the moment this article is very abstract and hard for a newbie to comprehend. We need something that builds a picture in the mind. --Treekids (talk) 19:40, 11 December 2007 (UTC)

Safety Charge Pumps
I have removed this but made a mistake in my edit summary. I said that the cited reference does not support the text - this is untrue, I mistakenly looked at the wrong ref because of the unconventional way this article is laid out (I will fix that in a moment). It turns out the edit is an exact copy of the ref and should therefore be deleted for a different reason - copyright violation. Besides that, I stand by the rest of what I said in the edit summary, the description is of a watchdog circuit, not a charge pump as meant in this article. The page referenced is not an acceptable ref since it is a blog and cannot be considered reliable. I have doubts whether this is really a widely used CNC term, but I don't know as it is not my field of engineering. However, if it is, it should be written about elsewhere (in the watchdog article or even its own article) and at most a hatnote would be needed here to disambiguate.  Sp in ni ng  Spark  18:25, 4 June 2009 (UTC)


 * As a bit of a belated followup to this, the safety/watchdoggy sense of the term is actually what brought me to this page (in hopes of discovering exactly what, if anything, was being charged or pumped). Accurate or not, this does seem to be the prevalent usage in CNCland. Here's a bit from the Gecko G540 manual (a popular stepper motor controller - and the reason I ended up here today - that integrates one labeled that way on its front panel):

''CHARGE PUMP: The G540 is equipped with a charge pump (watchdog timer) that disables the drive without a 10 kHz signal on pin 16 of the DB25 port. You can enable this by reversing what was done in STEP 3 and making sure that your parallel port is set to EPP mode. To do this, go into BIOS and set your parallel port to either “EPP” or “Send/Receive”; most parallel cards are set to ECP or “Send Only” by default.''


 * ...and the LinuxCNC software package implements what looks like a virtual charge pump, as discussed (at some length) in their wiki:

''In the most basic terms, in the LinuxCNC context, a charge pump is an HAL component that toggles a logic state at the rate of the thread that invokes it ( http://www.linuxcnc.org/docview/html/man/man9/charge_pump.9.html ). There is one input, charge-pump.enable which allows the output to toggle when no signal is connected (defaults to TRUE) or the input is TRUE. There is one output, charge-pump.out, which is either toggling TRUE/FALSE or is FALSE when the input is FALSE.  [...] Typically, the charge pump is used as a check for LinuxCNC being up and running, also known as a watchdog.''


 * I'm not sure how these got conflated in the first place, or whether a pointer to Watchdog timer would be entirely appropriate either - as the CNC sense seems to function more as a safety interlock than an actual timer... but I figured I should at least help to confuse the issue by dropping a note here.
 * You're welcome? :p
 * --71.234.116.22 (talk) 03:32, 21 February 2020 (UTC)

A bit of trivia that gave me a chuckle on the schematics
For the MOSFET charge pump schematic, it's in electronic reality the same as the first diagram. Connect gate to drain for a MOSFET or a base to collector in a bipolar transistor, you turn it into a diode. Just a bit of trivia, in a way, but hopefully educational to those unfamiliar with electronics. Years ago, we called these voltage multipliers. In television sets of CRT type, they were referred to as triplers (due to the tripling of voltage, due to the lower number of diode utilized due to technological constraints of the time). Further notable was the increase of voltage results in lower current being available, but the same (ignoring losses) power in wattage being available.Wzrd1 (talk) 10:07, 10 December 2014 (UTC)

Comments and questions
1. The article says "A charge pump is a kind of DC to DC converter ". Then it says "Another way to explain the operation of a charge pump is to consider it as the combination of a DC to AC converter (the switches) followed by a voltage multiplier."

The descriptions are inconsistent. The first sentence implies a DC voltage level shift. The second introduces the notion of DC-to-AC conversion followed by a voltage multiplier. Assuming that DC-to-DC conversion in the first statement refers to DC current or voltage conversion, the last part of the statement seems to refer to a DC-to-DC shift which in the end is what the first sentence says. The two sentences are contradictory and need to be revised.

2. "A charge pump providing a negative voltage spike has been used in NES-compatible games not licensed by Nintendo in order to stun the Nintendo Entertainment System lockout chip."

What does "stunning" the NES means? Is it some kind of jargon? This needs clarification.

3. This entry states "Charge pumps can double voltages, triple voltages, halve voltages, invert voltages, fractionally multiply or scale voltages". If that is the case then it's clear the input is DC voltage and the output is DC voltage. Basically it is like saying that charge pumps are similar to voltage multipliers. Yet, voltage multiplies have AC input and DC output. Charge pumps have DC input and DC output. Is that the main/subtle difference?

ICE77 (talk) 16:18, 19 August 2015 (UTC)


 * I agree with the criticisms above, I think this article has too limited a definition; it is not necessarily a DC-to-DC converter.  "Charge pump" refers to just the voltage multiplier and does not include the oscillator.   For example, the term "charge pump" is also used in smart card and RFID design for a diode capacitor multiplier that generates the higher DC voltage needed to power the chip from the low RF (AC) voltage from the antenna:, . Looking at all electrical usage of the term, , , , , , it is clear that the term "charge pump" refers to a diode-capacitor ladder network that uses an AC or pulsed current to generate a higher (or possibly lower) DC voltage by charging capacitors in series while discharging them in parallel, thus "pumping" charge in one direction, of which the Greinacher/Cockcroft–Walton circuit was the earliest example: ,  -- Chetvorno TALK 03:37, 20 August 2015 (UTC)


 * The issue is not with this article, but perhaps the ridiculously ambiguous words themselves 'charge pump', and the way it has broadened to something that nobody can really place a finger on in terms of what it is supposed to be. But at least the article provides some kind of start and also provides information about where these words pop up in various electronic and physics work, and also indicates that the definition has gray areas. KorgBoy (talk) 20:40, 21 March 2019 (UTC)