# IEC differentiator element (d/dt)

Canonical URL: https://eloragrid.ai/symbols/iec-differentiator
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: d/dt
Drawing use: Schematic
Reference families: IEC, Manufacturer

## Symbol convention

Convention: IEC
Form: Rectangular analogue element with d/dt function
IEC-style rectangular analogue element presentation; the IEC graphical symbols programme is cited for context only. Independent educational drawing; not certified IEC geometry or an IEC database identifier. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.
Related representation: [Op-amp differentiator](https://eloragrid.ai/symbols/op-amp-differentiator)

Analogue element marked d/dt whose output is proportional to the rate of change of its input.

## In plain English

### What does IEC differentiator element (d/dt) mean?

The differentiator element carries the d/dt function. Its output is proportional to how fast the input changes, so a ramp input gives a constant output and a step input gives a spike. In circuit form it is usually an op-amp with an input capacitor and feedback resistor, often with extra components to limit high-frequency gain.

### A simple example

Rate-of-change functions appear in derivative control terms, df/dt style supervision and edge detection on analogue signals. The drawing should state the time constant and any filtering, because pure differentiation amplifies noise.

### What the drawings help you do

The element does not show the noise-limiting network. Reviewers should check that the implementing circuit or software includes one.

### This particular reference

Analogue element marked d/dt whose output is proportional to the rate of change of its input. The integrator accumulates the input; the differentiator responds to its rate of change.

### Terms

- Signal: Electrical information passed between devices, rather than necessarily the main power supply.
- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)
- [Differentiator circuit reference, SBOA276](https://www.ti.com/lit/pdf/sboa276)


## What it represents

The differentiator element carries the d/dt function. Its output is proportional to how fast the input changes, so a ramp input gives a constant output and a step input gives a spike. In circuit form it is usually an op-amp with an input capacitor and feedback resistor, often with extra components to limit high-frequency gain.
Rate-of-change functions appear in derivative control terms, df/dt style supervision and edge detection on analogue signals. The drawing should state the time constant and any filtering, because pure differentiation amplifies noise.
The element does not show the noise-limiting network. Reviewers should check that the implementing circuit or software includes one.

## How to read it

- Noise sensitivity makes filtering essential.
- Check the time constant and limiting components.

## Information to show or reference

- State the time constant.
- Show or reference high-frequency limiting.
- Reference the implementing circuit or function block.

## Important distinction

The integrator accumulates the input; the differentiator responds to its rate of change.

## Facts

- Function: Rate of change of input
- Practical caution: Amplifies high-frequency noise
- Artwork scope: Original educational illustration; consult the applicable standard and the selected device documentation for the exact graphic

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC graphical symbols programme covering analogue elements; no geometry reproduced.
- [Differentiator circuit reference, SBOA276](https://www.ti.com/lit/pdf/sboa276) — Texas Instruments. Manufacturer differentiator circuit documentation.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.