一、Overview of Multispectral Sensors

Multispectral sensors use spectral separation technology to divide light into narrow bands. These bands are then converted into electrical signals by detectors, and after processing, the target multispectral features are extracted. The characteristics of substances are identified through the differences in reflection/radiation among different spectral bands. Composed of optical (imaging, spectral components), control and display sections (signal processing, image presentation), it features multi-band detection, high spectral resolution, and non-contact measurement. It is applied in fields such as agriculture, environment, medicine, industry, remote sensing, security, etc.

二、Principle of Implementation and Application of Technology

1、Leiditech EMCPerson drew the working principle diagram of the multispectral sensor as follows.

2、The wide application of multispectral technology

三、Leiditech Guide on Electrostatic Surge Protection for Multispectral Sensor Circuits

1：Testing certification standards

· Surge immunity: According to IEC 61000-4-5, at the input 24V power port, line-to-line ±2kV, line-to-ground ±4kV, tested with a 10/700μs waveform. 

· Electrostatic Discharge (ESD): Complies with IEC 61000-4-2, with contact discharge of ±8kV and air discharge of ±15kV; Medical equipment must achieve contact discharge of ±6kV and air discharge of ±8kV, and must pass YY 0505 certification.。

2：Core interface protection

As shown in the figure, the interface of the multispectral sensor chip mainly includes the power input port VCC, the signal interface I2C/UART, and the external interface (USB/Ethernet)。

l Input power protection

The 24V industrial power supply needs to take into account both surge and overcurrent protection: 

Surge protection: It is recommended to use TVS diode LM1K24CA (SMB package, VC = 35V, low breakdown voltage), with a protection level of up to 2KV; 

Overcurrent protection: SMD1812 series PTC (6-60V, 0.1-3.5A), with fast response time and reusable feature; 

Reverse polarity protection: Schottky diode SK56C (60V/5A), reduces the risk of damage when the power supply is connected in reverse. 

Or you can use the conventional solution: the pre-stage uses GDT 2R090-5S + MOV, and the post-stage uses TVS for further fine clamping. 

Signal interface protection 

UART interface: Lebao adopts a single-chip protection design to save space and ensure signal integrity. ULC3304P10, ULC0524P are used, meeting IEC61000-4-2, level 4, contact discharge 30kV, air discharge 30kV.

l Power rail electrostatic protection 

For the simulation power supply (3.3V), Lebao uses ESD0321CW (DFN0603 package, 30pF capacitor, 21A discharge current); 

For the digital power supply (1.8V), the lightning protection component ESD1821C (DFN0603, 25pF, 18A) is adopted to reduce power supply ripple and electrostatic interference. 

Gigabit Network Lightning Strike and Surge Protection Solution

For the 1000M network port surge protection used outdoors, a two-level protection method is adopted. The front stage of the transformer uses GDT 3R090-5S to release the current, and the rear stage uses ESD GBLC03C for precise clamping, with the junction capacitance being less than 0.6pF. This ensures the integrity of the signal under high temperatures and meets IEC61000-4-2, level 4, contact discharge of 30kV, air discharge of 30kV. IEC61000-4-5 10/700μs, 40Ω, 6kV, ±5 times. This solution ensures no packet loss during high-temperature transmission.

Leiditech is committed to becoming a leading brand in electromagnetic compatibility solutions and component supply, offering products such as ESD, TVS, TSS, GDT, MOV, MOSFET, Zener, inductors, etc. Leiditech has an experienced R&D team that can provide personalized customization services based on customer needs, offering the best solutions to customers.