PD438B/S46 Silicon PIN Photodiode Datasheet - 4.8mm Semi-Lens - Black Package - Takardar Fasaha ta Hausa

1. Bayanin Samfur

PD438B/S46 shine babban silicon PIN photodiode wanda aka ƙera don aikace-aikacen da ke buƙatar saurin amsawa da hankali mai girma. An sanya shi a cikin ƙaramin akwati na filastik mai siffar silinda da kallon gefe tare da semi-lens na 4.8mm. Babban fasalin wannan na'urar shine epoxy ɗin da aka yi masa, wanda aka tsara don yin aiki azaman tace infrared (IR) mai haɗaka. Wannan tacewa yana daidaitawa da fitilun IR na gama gari, yana haɓaka ayyukansa a aikace-aikacen gano IR ta hanyar rage hankali ga hasken da ba a so.

Babban fa'idodin wannan photodiode sun haɗa da saurin amsawarsa, waɗanda ke da mahimmanci don saurin watsa bayanai da aikace-aikacen sauyawa, da kuma babban hankalinsa na hoto, yana ba shi damar gano ƙananan matakan haske yadda ya kamata. Ƙaramin ƙarfin haɗin gwiwarsa yana ba da gudummawa ga saurin amsawa kuma yana sa ya dace da da'irori masu mitar girma. An gina na'urar ta amfani da kayan da ba su da gubar kuma tana bin ƙa'idodin muhalli kamar RoHS da EU REACH, yana sa ya dace don amfani da shi a cikin samfuran da ke da ƙaƙƙarfan buƙatun bin ƙa'ida.

Babban kasuwanni da aikace-aikacen da aka yi niyya don PD438B/S46 suna cikin na'urorin lantarki na masu amfani, sarrafa masana'antu, da tsarin sadarwa. Ƙayyadaddun sa sun sa ya zama kayan aiki mai kyau ga masu zane a kan hanyoyin haɗin gwiwar bayanan gani masu sauri, tsarin gano kasancewa, da kayan aikin auna haske daidai.

2. Bincike Mai Zurfi na Sigogi na Fasaha

2.1 Matsakaicin Matsakaicin Matsayi

An ƙididdige na'urar don jure matsakaicin ƙarfin lantarki na baya (VR) na 32V. Matsakaicin raguwar wutar lantarki (Pd) shine 150 mW, wanda ke ayyana iyakokin zafin aiki. Ana iya siyar da igiyoyin a zafin jiki har zuwa 260°C na tsawon lokacin da bai wuce dakika 5 ba, wanda ya dace da daidaitattun hanyoyin siyar da reflow. An ƙayyade kewayon zafin aiki daga -40°C zuwa +85°C, kuma ana iya adana shi a cikin yanayi daga -40°C zuwa +100°C. Waɗannan ƙimar suna tabbatar da ingantaccen aiki a cikin yanayi iri-iri.

2.2 Halayen Lantarki da Hasken

Amsar haske na photodiode an ayyana ta ta hanyar kewayon bandwidth na haske (λ0.5), wanda ya tashi daga 840 nm zuwa 1100 nm. Tsawon zango mafi girma na hankali (λp) yana a 940 nm, yana sanya shi a cikin yankin kusa-infrared, wanda aka saba amfani dashi don sarrafa nesa, firikwensin gani, da sadarwa ta sararin samaniya.

Ƙarƙashin hasken haske na 5 mW/cm² a 940 nm, matsakaicin ƙarfin lantarki na buɗe kewayon (VOC) shine 0.35V. Matsakaicin ƙarfin lantarki na gajeriyar kewayon (ISC), wanda aka auna a 1 mW/cm² da 940 nm, yawanci shine 18 µA. Wannan siga shine ma'aunin kai tsaye na ikon samar da wutar lantarki na na'urar a ƙarƙashin haske.

Ƙarfin lantarki na haske na baya (IL) shine photocurrent da aka samar lokacin da diode ke da karkatarwa ta baya. A VR=5V da Ee=1 mW/cm² (λp=940nm), ƙimar al'ada ita ce 18 µA, tare da mafi ƙarancin ƙimar da aka tabbatar na 10.2 µA. Ƙarfin lantarki na duhu (Id), wanda shine ƙarfin lantarki na yaduwa a ƙarƙashin rashin haske a VR=10V, yawanci shine 5 nA tare da matsakaicin 30 nA. Ƙaramin ƙarfin lantarki na duhu yana da mahimmanci don samun ingantaccen rabo na sigina zuwa amo, musamman a cikin yanayin gano haske kaɗan.

An ƙayyade ƙarfin lantarki na rushewar baya (BVR) a mafi ƙarancin 32V lokacin da ƙarfin lantarki na 100 µA ke gudana, tare da ƙimar al'ada har zuwa 170V. Matsakaicin ƙarfin ƙarfin tashar gaba ɗaya (Ct) a VR=5V da 1 MHz yawanci shine 18 pF. Wannan ƙaramin ƙarfin ƙarfi shine babban abin da ke ba da damar saurin tashi da faɗuwa. Lokutan tashi da faɗuwa (tr/tf) duka yawanci shine 50 nanoseconds lokacin da aka kunna na'urar a VR=10V tare da juriyar kaya (RL) na 1 kΩ.

3. Bincike na Lanƙwasa Ayyuka

Takardar bayanan tana ba da lanƙwasa halaye da yawa waɗanda ke ba da zurfin fahimta game da halayen na'urar a ƙarƙashin yanayi daban-daban.

Hoto na 1: Ragewar Wutar Lantarki vs. Yanayin Yanayiyana kwatanta raguwar matsakaicin ƙarfin wutar lantarki da aka yarda yayin da yanayin yanayi ke ƙaruwa. Wannan jadawali yana da mahimmanci don ƙirar sarrafa zafin jiki don hana zafi mai yawa da tabbatar da dogon lokacin aminci.

Hoto na 2: Hankalin Haskenyana nuna amsawar dangi na photodiode a cikin bakan tsawon zango daga kusan 600 nm zuwa 1200 nm. Lanƙwasa ya kai kololuwa a 940 nm kuma yana nuna ingantaccen aikin tacewa na epoxy ɗin, wanda ke rage amsa a wajen band ɗin IR da aka yi niyya.

Hoto na 3: Ƙarfin Lantarki na Duhu vs. Yanayin Yanayiyana nuna yadda ƙarfin lantarki na yaduwa (Id) ke ƙaruwa da yawa tare da zafin jiki. Wannan dangantaka tana da mahimmanci ga aikace-aikacen da ke aiki a matsanancin zafin jiki, kamar yadda yake ayyana ƙasan amo na firikwensin.

Hoto na 4: Ƙarfin Lantarki na Hasken Baya vs. Hasken Hasken (Ee)yana kwatanta dangantakar layi tsakanin photocurrent da aka samar da ƙarfin hasken da ya faru. Wannan layin shine ainihin kaddarorin PIN photodiodes kuma yana da mahimmanci ga aikace-aikacen auna haske na analog.

Hoto na 5: Ƙarfin Ƙarfin Tasha vs. Ƙarfin Lantarki na Bayayana nuna cewa ƙarfin haɗin gwiwa yana raguwa tare da ƙara ƙarfin lantarki na baya. Masu zane za su iya amfani da wannan dangantaka don haɓaka saurin da'irar su ta hanyar zaɓar wurin da ya dace.

Hoto na 6: Lokacin Amsa vs. Juriyar Kayayana nuna yadda lokacin tashi/faɗuwa na siginar fitarwa na photodiode ke shafar juriyar kaya da aka haɗa da shi. Ana samun saurin amsawa tare da ƙananan juriyar kaya, ko da yake wannan na iya ciniki da jujjuyawar ƙarfin fitarwa.

4. Bayanan Injiniya da Marufi

4.1 Girman Marufi

PD438B/S46 yana zuwa a cikin akwati mai siffar silinda da kallon gefe. Babban girmansa ya haɗa da diamita na jiki da tsayin semi-lens kamar yadda aka ayyana a cikin zanen marufi. Duk ƙimar da ba a ƙayyade ba don ma'auni na layi shine ±0.25mm. Marufin yana da launin baki, wanda ke taimakawa wajen rage tsangwama na haske. Tsarin kallon gefe yana ba da damar gano haske daga wata hanya mai kama da jirgin PCB, wanda ke da amfani a aikace-aikace kamar gano takarda a cikin na'urorin bugawa ko gano gefe.

4.2 Gano Polarity

Ana gano cathode ta hanyar mafi tsayin jagora, tsaga, ko wuri mai lebur a jikin marufi. Dole ne a lura da polarity daidai yayin haɗawa, saboda karkatarwa ta baya shine daidaitaccen yanayin aiki don photodiodes da ake amfani da su a yanayin photoconductive.

5. Jagororin Solder da Haɗawa

Na'urar ta dace da hanyoyin siyar da igiyar ruwa da reflow. Matsakaicin matsakaicin ƙimar zafin jiki na siyar da jagora shine 260°C, tare da bayanin cewa lokacin siyar bai kamata ya wuce dakika 5 ba. Ana ba da shawarar bin jagororin IPC na yau da kullun don siyar da kayan lantarki. Ya kamata a adana na'urar a cikin busasshiyar yanayi, mai hana tashin hankali a cikin ƙayyadaddun kewayon zafin ajiya na -40°C zuwa +100°C don hana sha da lalata ta electrostatic.

6. Bayanan Marufi da Oda

Daidaitaccen ƙayyadaddun shiryawa shine kamar haka: Ana shirya guda 200 zuwa 500 a cikin jakar shinge guda ɗaya. Ana sanya jakunkuna irin wannan guda shida a cikin akwati na ciki guda ɗaya. Sannan ana shirya akwatunan ciki goma a cikin babban akwatin jigilar kaya guda ɗaya. Alamar da ke kan marufi ta haɗa da filayen don lambar ɓangaren abokin ciniki (CPN), lambar ɓangaren masana'anta (P/N), adadin shiryawa (QTY), da lambar kuri'a (LOT No.). Sauran filayen kamar CAT, HUE, da REF, waɗanda aka saba don LED don nuna ƙarfi, tsawon zango, da kwandon wutar lantarki, ba su dace da wannan photodiode ba saboda ba a yi masa kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon kwandon 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. Application Suggestions

.1 Typical Application Scenarios

• High-Speed Photo Detection:Ideal for optical encoders, data communication over plastic optical fiber (POF), and laser beam detection where nanosecond response is required.
• Camera Applications:Can be used for ambient light sensing (ALS) or IR proximity detection in smartphones, tablets, and digital cameras. The built-in IR filter helps in accurately measuring IR levels.
• Optoelectronic Switches:Suitable for object detection, counting, and position sensing in vending machines, industrial automation, and security systems.
• Consumer Electronics:Used in VCRs and video cameras for tape-end detection or control signal reception.

.2 Design Considerations

When designing a circuit with the PD438B/S46, consider the following:

• Bias Voltage:A reverse bias voltage (typically 5V to 10V as per datasheet conditions) is applied to widen the depletion region, reducing capacitance and improving speed. Ensure the voltage does not exceed the maximum rating of 32V.
• Load Resistor (RL):The value of RL in the transimpedance configuration directly affects bandwidth and output voltage. A smaller RL gives faster response but lower output signal. Figure 6 in the datasheet is a key reference.
• Amplification:The photocurrent is small (microamps). A transimpedance amplifier (TIA) is almost always used to convert this current into a usable voltage signal. Choose an op-amp with low input bias current and sufficient bandwidth.
• Noise Reduction:Shield the photodiode and its connecting traces from electrical noise. Use a bypass capacitor close to the device's power pins if an active bias circuit is used. The low dark current helps maintain a good signal-to-noise ratio.
• Optical Considerations:Ensure the lens is clean and unobstructed. The side-view package may require careful mechanical design to align the light path correctly.

. Technical Comparison and Differentiation

Compared to standard PN photodiodes, the PIN structure of the PD438B/S46 offers distinct advantages. The intrinsic (I) region between the P and N layers creates a larger depletion region. This results in two primary benefits:) Lower Junction Capacitance:The larger depletion region acts like a wider dielectric, significantly reducing capacitance (typically 18 pF), which is the main enabler for high-speed operation.) Improved Linearity and Sensitivity:The wide intrinsic region allows more efficient collection of photogenerated carriers across a broader volume, leading to better linearity in photocurrent vs. irradiance and potentially higher quantum efficiency at its peak wavelength.

Furthermore, the integration of an IR-filtering epoxy directly into the package is a differentiating feature. It eliminates the need for a separate external IR filter, saving space, reducing cost, and simplifying assembly. This makes it particularly advantageous for compact consumer electronics designs.

. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the difference between short-circuit current (ISC) and reverse light current (IL)?

A: ISC is measured with zero volts across the diode (short-circuit condition). IL is measured when the diode is reverse-biased (e.g., at VR=5V). In practice, for a PIN photodiode, these values are very similar because the photocurrent is largely independent of the reverse bias voltage in the normal operating range.

Q: Why is the rise/fall time specified with a 1 kΩ load?

A: The 1 kΩ load represents a common load condition for testing and for simple circuits. The actual response time in your application will depend on your specific circuit's load resistance and parasitic capacitances, as shown in Figure 6.

Q: Can this photodiode be used for visible light detection?

A: While the silicon material itself is sensitive to visible light (as seen in the spectral curve extending down to ~600nm), the black epoxy package acts as a strong filter. Its sensitivity in the visible spectrum will be greatly attenuated compared to its peak at 940 nm. It is primarily designed for near-IR applications.

Q: How do I interpret the "Typ." values in the characteristics table?

A> "Typ." stands for typical value, which is the expected average under specified conditions. It is not guaranteed. For design purposes, especially for critical parameters, you should use the "Min." or "Max." values to ensure your circuit will function correctly across all production variations and conditions.

. Practical Design and Usage Examples

Example 1: Simple Object Detection Switch

A basic opto-switch can be built by pairing the PD438B/S46 with an IR LED (e.g., emitting at 940 nm). The photodiode is connected in reverse bias with a pull-up resistor to Vcc (e.g., 5V). The output node between the resistor and the photodiode's cathode is fed to a comparator or a microcontroller's digital input pin. When an object interrupts the IR beam between the LED and the photodiode, the photocurrent drops, causing the voltage at the output node to rise, triggering the detection signal. The fast response time allows detection of rapidly moving objects.

Example 2: Ambient Light Sensor with Microcontroller

For analog light level measurement, the photodiode can be connected to a transimpedance amplifier. The output voltage of the TIA, which is proportional to the incident IR light intensity, is then fed into an analog-to-digital converter (ADC) input of a microcontroller. The MCU can use this reading to automatically adjust the brightness of a display or to determine if an IR remote control signal is present. The integrated IR filter helps ensure the reading is specific to the IR component of ambient light.

. Principle of Operation Introduction

A PIN photodiode is a semiconductor device that converts light into electrical current. It consists of a layer of intrinsic (undoped or lightly doped) semiconductor material (the "I" region) sandwiched between a P-type layer and an N-type layer. When photons with energy greater than the semiconductor's bandgap (for silicon, light with wavelength less than ~1100 nm) strike the device, they can create electron-hole pairs in the intrinsic region. When a reverse bias voltage is applied, it creates a strong electric field across the intrinsic region. This field swiftly sweeps the photogenerated carriers towards the respective terminals—electrons to the N-side and holes to the P-side—generating a measurable photocurrent in the external circuit. The width of the intrinsic region is key: it allows efficient carrier generation and collection while keeping the device capacitance low.

. Technology Trends and Context

Silicon PIN photodiodes like the PD438B/S46 represent a mature and highly reliable technology. Current trends in this field focus on several areas:Miniaturization:Developing smaller package footprints (e.g., chip-scale packages) for space-constrained applications like wearable devices and mobile phones.Integration:Combining the photodiode with amplification, digitization, and signal processing circuitry on a single chip to create smart optical sensors.Enhanced Performance:Research into structures like avalanche photodiodes (APDs) for applications requiring extreme sensitivity, though these are more complex and expensive.New Materials:Exploration of materials like germanium or III-V compounds (e.g., InGaAs) for detection in longer infrared wavelengths, which are not accessible with standard silicon. For mainstream near-IR applications up to 1100 nm, silicon remains the dominant, cost-effective material of choice due to its excellent manufacturability and performance.