PD333-3B/L1 5mm Photodiode Datasheet - 5mm Diameter - 32V Reverse Voltage - Black Lens - English Technical Document

1. Product Overview

The PD333-3B/L1 is a high-speed, high-sensitivity silicon PIN photodiode encapsulated in a standard 5mm diameter plastic package. Its primary function is to convert incident light, particularly in the infrared spectrum, into an electrical current. The device features a black epoxy lens, which enhances its sensitivity to infrared radiation while minimizing response to visible light. This makes it particularly suitable for applications requiring detection in the near-infrared range. The core advantages of this component include its fast response time, high photosensitivity, and small junction capacitance, which are critical for high-speed signal detection. It is designed as a lead-free (Pb-free) component and complies with relevant environmental regulations such as RoHS and EU REACH.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

The device is designed to operate reliably within specified limits. Exceeding these ratings may cause permanent damage.

• Reverse Voltage (V_R): 32 V - The maximum reverse bias voltage that can be applied across the photodiode terminals.
• Operating Temperature (T_opr): -25°C to +85°C - The ambient temperature range for normal operation.
• Storage Temperature (T_stg): -40°C to +100°C - The temperature range for non-operational storage.
• Soldering Temperature (T_sol): 260°C - The peak temperature the device can withstand during soldering processes.
• Power Dissipation (P_c): 150 mW - The maximum power the device can dissipate at or below 25°C ambient temperature.

2.2 Electro-Optical Characteristics

These parameters define the photodiode's performance under standard test conditions (Ta=25°C).

• Spectral Bandwidth (λ_0.5): 840 nm to 1100 nm - The wavelength range where the responsivity is at least half of its peak value.
• Peak Sensitivity Wavelength (λ_P): 940 nm (Typical) - The wavelength of light at which the photodiode is most sensitive.
• Open-Circuit Voltage (V_OC): 0.44 V (Typical) - The voltage generated across the open terminals when illuminated (E_e=5 mW/cm², λ_p=940nm).
• Short-Circuit Current (I_SC): 10 µA (Typical) - The current flowing when the terminals are short-circuited under illumination (E_e=1 mW/cm², λ_p=940nm).
• Reverse Light Current (I_L): Min. 15 µA - The photocurrent generated under reverse bias (V_R=5V, E_e=1 mW/cm², λ_p=940nm). This is a key parameter for signal detection.
• Reverse Dark Current (I_D): Max. 30 nA - The small leakage current that flows under reverse bias in complete darkness (V_R=10V). A lower value is desirable for better signal-to-noise ratio.
• Reverse Breakdown Voltage (V_BR): Min. 32 V, Typ. 170 V - The reverse voltage at which the junction breaks down and current increases sharply.
• Total Capacitance (C_t): 6.0 pF (Typical) - The junction capacitance under reverse bias (V_R=5V, f=1MHz). A low capacitance is crucial for high-speed operation.
• Rise/Fall Time (t_r/t_f): 10 ns (Typical) - The time required for the output signal to rise from 10% to 90% (or fall from 90% to 10%) of its final value (V_R=10V, R_L=100Ω). This defines the maximum switching speed.

3. Binning System Explanation

The PD333-3B/L1 is sorted into different bins based on its Reverse Light Current (I_L) performance under specific test conditions (E_e=1mW/cm², λ_p=940nm, V_R=5V). This allows designers to select components with consistent performance for their application.

The datasheet also notes standard tolerances: Luminous Intensity ±10%, Dominant Wavelength ±1nm, and Forward Voltage ±0.1V, though the latter two are more relevant to LEDs than this photodiode.

4. Performance Curve Analysis

The datasheet includes several characteristic curves that illustrate device behavior under varying conditions. These are essential for circuit design and performance prediction.

4.1 Spectral Sensitivity

The spectral response curve shows the device's relative sensitivity across different wavelengths. It peaks at 940 nm (infrared) and has significant response from approximately 840 nm to 1100 nm. This confirms its suitability for IR-based systems like remote controls and proximity sensors.

4.2 Temperature Dependence

Curves are provided showing the relationship between Reverse Dark Current and Ambient Temperature, and Power Dissipation vs. Ambient Temperature. The dark current typically increases with temperature, which can affect the noise floor in sensitive applications. The power derating curve shows how the maximum allowable power dissipation decreases as ambient temperature rises above 25°C.

4.3 Electrical Characteristics

Key graphs include:

• Reverse Light Current vs. Irradiance (E_e): Shows the linear relationship between generated photocurrent and incident light power density, a fundamental property of photodiodes.
• Terminal Capacitance vs. Reverse Voltage: Demonstrates how junction capacitance decreases with increasing reverse bias voltage. Operating at a higher reverse voltage (within limits) can improve speed by reducing capacitance.
• Response Time vs. Load Resistance: Illustrates how the rise/fall time is affected by the load resistor (R_L) in the circuit. A smaller R_L generally leads to faster response but a smaller output voltage swing.

5. Mechanical and Package Information

The device uses a standard 5mm diameter round plastic package. The package dimension drawing provides critical measurements for PCB footprint design and mechanical integration. Key dimensions include the overall diameter (5mm), lead spacing, and component height. The drawing specifies a general tolerance of ±0.25mm unless otherwise noted. The package features two axial leads for electrical connection. The black epoxy body acts as the lens and IR filter. Proper polarity identification should be based on the datasheet's terminal diagram; typically, the cathode is indicated by a longer lead, a flat spot on the package, or a specific marking.

6. Soldering and Assembly Guidelines

The component is rated for a maximum soldering temperature of 260°C. Standard reflow or wave soldering profiles for lead-free processes can be used, ensuring the peak temperature and time above liquidus are controlled to prevent thermal damage. Hand soldering should be performed quickly with a temperature-controlled iron. It is recommended to store the components in a dry environment to prevent moisture absorption, which could cause issues during soldering (popcorning).

7. Packaging and Ordering Information

The standard packing specification is 500 pieces per bag, 5 bags per box, and 10 boxes per carton, totaling 25,000 pieces per carton. The label on the packaging includes fields for Customer Product Number (CPN), Product Number (P/N), Packing Quantity (QTY), and relevant performance ranks (CAT for intensity, etc.), along with Lot Number and date coding for traceability.

8. Application Suggestions

8.1 Typical Application Scenarios

• High-Speed Photo Detection: Suitable for data transmission over fiber optics, barcode scanners, and optical encoders due to its 10ns response time.
• Security Systems: Can be used in intrusion detection beams, smoke detectors, or as a receiver for IR-based security communication.
• Camera Applications: Useful for light metering, auto-focus assist systems, or as an IR cut-filter monitor.
• Industrial Sensing: Object detection, counting, and position sensing in automated equipment.

8.2 Design Considerations

• Bias Circuit: The photodiode can be used in photovoltaic (zero bias) mode for low-noise applications or photoconductive (reverse bias) mode for higher speed and linearity. The 32V maximum reverse voltage allows for a wide range of bias choices.
• Amplification: The output current is small (microamps), so a transimpedance amplifier (TIA) is almost always required to convert the current to a usable voltage signal.
• Noise: For sensitive applications, consider the dark current and its temperature dependence. Shielding and careful PCB layout are necessary to minimize pickup of electrical noise.
• Optical Filtering: The black epoxy provides some filtering, but for specific wavelength selection, an additional bandpass optical filter may be needed.

9. Technical Comparison and Differentiation

Compared to generic photodiodes, the PD333-3B/L1 offers a balanced combination of speed (10ns), sensitivity (min 15µA @ specified conditions), and a robust 32V reverse voltage rating in a common 5mm package. Its silicon construction and PIN structure provide a good trade-off between cost, speed, and sensitivity for near-IR applications. Alternatives might include photodiodes with smaller packages for space-constrained designs, those with different spectral responses (e.g., visible light), or avalanche photodiodes (APDs) for applications requiring internal gain, though APDs are more complex and expensive.

10. Frequently Asked Questions (FAQ)

Q: What is the difference between photovoltaic and photoconductive mode?
A: In photovoltaic mode (zero bias), the photodiode generates its own voltage/current, offering very low dark current and noise. In photoconductive mode (reverse bias), an external voltage is applied, which reduces junction capacitance (increasing speed) and improves linearity, at the cost of slightly higher dark current.

Q: How do I choose the right bin?
A: Select a bin based on the required minimum signal current for your application. Using a higher bin ensures a stronger signal but may have cost implications. For consistency in production, specify a single bin.

Q: Can this photodiode be used for visible light detection?
A: While it has some response in the visible red spectrum, its peak is at 940nm (IR), and the black epoxy attenuates visible light. For primary visible light detection, a photodiode with a clear or color-specific lens and a peak wavelength in the visible range would be more appropriate.

Q: What value of load resistor (R_L) should I use?
A: It depends on the required speed and signal level. A smaller R_L (e.g., 50Ω) gives faster response but a smaller voltage output (Vout = I_ph * R_L). A larger R_L gives a larger voltage but slower response due to the RC time constant formed with the diode capacitance. Refer to the "Response Time vs. Load Resistance" curve.

11. Practical Design Case

Case: Simple Object Detection Sensor
A common use is a break-beam sensor. An IR LED emitting at 940nm is placed opposite the PD333-3B/L1 photodiode. The photodiode is operated in photoconductive mode with a 5V reverse bias through a load resistor (e.g., 10kΩ). Under normal conditions, the IR light hits the diode, generating a photocurrent and creating a voltage drop across the resistor. When an object breaks the beam, the photocurrent drops significantly, causing a large change in the voltage across the resistor. This voltage signal can be fed into a comparator to generate a digital interrupt for a microcontroller. The 10ns response time is far faster than needed for this application, but the high sensitivity ensures reliable operation even with weaker IR sources or over longer distances.

12. Principle of Operation

A PIN photodiode is a semiconductor device with an intrinsic (I) region sandwiched between P-type and N-type regions. When photons with energy greater than the semiconductor's bandgap strike the device, they create electron-hole pairs in the intrinsic region. Under the influence of an internal built-in potential (photovoltaic mode) or an applied reverse bias (photoconductive mode), these charge carriers are swept apart, creating a measurable photocurrent that is proportional to the incident light intensity. The wide intrinsic region in a PIN structure reduces junction capacitance compared to a standard PN photodiode, enabling higher speed operation.

13. Industry Trends

The demand for photodiodes continues to grow in areas like consumer electronics (smartphone sensors, wearables), automotive (LiDAR, driver monitoring), industrial automation, and communication (data centers). Trends include further miniaturization into chip-scale packages, integration with on-chip amplification and signal processing circuitry, development of photodiodes for new wavelength ranges (e.g., short-wave infrared), and enhancement of performance parameters like lower noise and higher speed to meet the requirements of emerging technologies.