{"id":2242,"date":"2026-06-24T07:24:28","date_gmt":"2026-06-24T07:24:28","guid":{"rendered":"https:\/\/photo-detector.com\/?p=2242"},"modified":"2026-06-24T07:24:35","modified_gmt":"2026-06-24T07:24:35","slug":"chip-de-fotodiodo-pin-de-940-nm","status":"publish","type":"post","link":"https:\/\/photo-detector.com\/es\/940nm-pin-photodiode-chip\/","title":{"rendered":"Selecci\u00f3n del mejor chip de fotodiodo PIN de 940 nm"},"content":{"rendered":"\n

If you are an optical R&D engineer designing galvo-based industrial laser scanners, you know how annoying the receiver end can be. You spend weeks perfecting the laser source, the mirrors, the scanning angles, only to realize the receiver is slow or deaf to the signals. Often, the culprit is choosing the wrong 940nm PIN photodiode chip<\/strong>. At 940nm, silicon\u2019s light absorption starts to drop off quite a bit, making sensor selection a delicate balancing act.<\/p>\n\n\n\n

Selecting a high-quality 940nm PIN photodiode chip<\/strong> isn’t just about picking a part from a datasheet; it’s about matching chip physics with real-world system limits. Whether you are working on LiDAR, B2B sorting systems, or high-speed rangefinders, selecting the right 940nm PIN photodiode chip<\/strong> can make or break your design. Let’s dive deep into what matters when picking a 940nm PIN photodiode chip<\/strong> for industrial laser scanning.<\/p>\n\n\n\n

When you start sourcing a 940nm PIN photodiode chip<\/strong>, you’re looking for a balance between speed, sensitive area, and responsivity. If the active area of the 940nm PIN photodiode chip<\/strong> is too small, alignment becomes a nightmare. If the active area of the 940nm PIN photodiode chip<\/strong> is too big, the capacitance slows down your system. You cannot afford to make the wrong choice when designing high-speed industrial scanners. Let’s look at how to navigate these challenges.<\/p>\n\n\n\n

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Active Area vs. Speed: The Ultimate Trade-off in a 940nm PIN Photodiode Chip<\/h2>\n\n\n\n

Let’s get right into the physics. Why can’t we just use a massive active area for our 940nm PIN photodiode chip<\/strong>? It would make laser alignment so much easier, right? Yes, but your circuit would become painfully slow. When selecting a 940nm PIN photodiode chip<\/strong>, you’re constantly fighting junction capacitance.<\/p>\n\n\n\n

The junction capacitance of a 940nm PIN photodiode chip<\/strong> acts like a low-pass filter in your receiver circuit. To keep things moving fast in a high-speed galvo scanner, you need that capacitance as low as possible. If your 940nm PIN photodiode chip<\/strong> has a high capacitance, your signal rise time increases, and you lose the sharp edges of your reflected laser pulses. This is a common issue when trying to use a generic 940nm PIN photodiode chip<\/strong> that wasn’t specifically optimized for high-speed laser detection.<\/p>\n\n\n\n

For most industrial galvo systems, you want to look at a silicon PIN photodiode die<\/a><\/strong> that offers a moderate active area but uses special NIR enhancement to keep the depletion region thick. A thick depletion region lowers the capacitance while maximizing the absorption of 940nm photons. This means your 940nm PIN photodiode chip<\/strong> can remain highly responsive without turning into a slow, capacitive slug.<\/p>\n\n\n\n

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The Math Behind Junction Capacitance and Rise Time<\/h2>\n\n\n\n

Let’s look at the actual formulas you need to use during your design phase. Don’t worry, we won’t use complex LaTeX; we will keep it simple and easy to copy directly into your notes.<\/p>\n\n\n\n

The classic formula for junction capacitance of a 940nm PIN photodiode chip<\/strong> is:<\/p>\n\n\n\n

Junction Capacitance (Cj) = (Permittivity of Silicon * Active Area) \/ Depletion Width<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n