IoTClass / Inside the measurement
Conceptual · not to scale

Inside a Photodiode

Peel from the case to the element. Follow the readout through this conceptual model.

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The full text version below describes every layer. All measurement explanations are available without 3D.
Case: optical window and two leadsA photodiode produces current in response to incoming light. [Overview: Photons In, Current Out · Photodiode current]

Drag to rotate; pinch to zoom. With the view focused: arrow keys rotate, + / − zoom, 1–3 choose a layer, Home resets rotation and zoom. Step advances to the next layer; Reset returns to the case and default view. Layer buttons select a view directly. The page does not move on its own.

Layer 1 of 3 / Outside

Case: optical window and two leads

A photodiode produces current in response to incoming light. [Overview: Photons In, Current Out · Photodiode current]

Teaching view: The brown package has a top window and two silver leads. Light reaches the detector through the window, and the leads provide its electrical connections.

The measurement to rememberLight falling on a photodiode produces current. A transimpedance amplifier converts that small current into a usable voltage. [Overview: Photons In, Current Out · Photodiode current] [Transimpedance and ToF Readout]

Full text version · every layer

1 · Case: optical window and two leads

A photodiode produces current in response to incoming light. [Overview: Photons In, Current Out · Photodiode current]

Teaching view: The brown package has a top window and two silver leads. Light reaches the detector through the window, and the leads provide its electrical connections.

2 · Interface: current-to-voltage readout

A transimpedance amplifier converts photodiode current into a usable voltage. [Transimpedance and ToF Readout]

Teaching view: The detector chip sits on a metal support connected to the leads, beside a gold connection pad. An external amplifier connects to the detector and turns its current into voltage.

3 · Element: light-sensitive surface

Incoming photons free charge carriers, producing current proportional to the light landing on the photodiode. [Overview: Photons In, Current Out · Photodiode current]

Teaching view: The purple surface represents the light-sensitive part of the photodiode above a blue layer, beside a gold connection pad. Incoming light frees charge carriers in the photodiode and produces current.

Explode separates the conceptual layers; X-ray makes the case translucent. External package dimensions follow the model specification; internal teaching geometry is conceptual, not to scale, and is not manufacturer CAD or a wiring diagram.