The model "MMBT5551" refers to a specific transistor from the ON Semiconductor brand. It is a NPN transistor designed for general-purpose switching and amplification. It is commonly used in various electronic circuits, including signal amplification, audio applications, and as a switch for low-power control systems.
Here is a detailed explanation based on your request:
1. MMBT5551 Package and Pinout
The MMBT5551 transistor comes in a TO-92 package. The TO-92 is a widely used package for small transistors. The package typically consists of three pins, each serving a specific function in the circuit.
Pin Function Description: Pin Pin Name Function 1 Collector The collector is where the current flows from the load to the transistor. This pin typically connects to the load resistor or the supply voltage in a switching application. 2 Base The base controls the transistor’s operation by providing the signal that determines whether the transistor is on (conducting) or off (non-conducting). A small current at this pin controls the larger current flow from collector to emitter. 3 Emitter The emitter is where the current exits the transistor and is often connected to ground (for NPN transistors). This is the reference pin for the base-emitter voltage.2. Package Type and Pinout
The MMBT5551 comes in the TO-92 package, which is a small plastic package suitable for through-hole mounting on a PCB (Printed Circuit Board). It typically has three leads, arranged in a specific pattern as mentioned above.
3. Detailed Pin Function List for the MMBT5551
In the TO-92 package for the MMBT5551, there are 3 pins, each performing essential tasks. The functionality and usage details for each pin are as follows:
Pin Number Pin Name Pin Function 1 Collector The collector is responsible for receiving the current flowing through the load (such as a resistor) and supplies the necessary current to the base to allow conduction. This pin typically connects to the positive voltage or load. 2 Base The base controls the current flowing from the collector to the emitter. A small current at the base will cause a much larger current to flow between the collector and emitter, enabling amplification or switching. It is the input for the transistor. 3 Emitter The emitter serves as the output pin and typically connects to ground in NPN configurations. The emitter current flows out of the transistor when it is conducting. It is often the pin that the load is connected to in switching applications.4. 20 Frequently Asked Questions (FAQs) for the MMBT5551
Q1: What is the maximum collector current for the MMBT5551?
A1: The maximum collector current for the MMBT5551 is 800mA.
Q2: What is the operating voltage range for the MMBT5551?
A2: The MMBT5551 can operate with a collector-emitter voltage (Vce) up to 80V.
Q3: Can I use the MMBT5551 for high-frequency applications?
A3: Yes, the MMBT5551 is suitable for low to medium-frequency applications and can handle frequencies up to 250MHz.
Q4: What is the power dissipation of the MMBT5551?
A4: The MMBT5551 can dissipate a maximum power of 500mW.
Q5: Is the MMBT5551 suitable for digital circuits?
A5: Yes, it can be used in digital circuits where a small signal is amplified or used as a switch.
Q6: What is the current gain (hFE) of the MMBT5551?
A6: The current gain (hFE) of the MMBT5551 is typically between 110 and 800, depending on the operating conditions.
Q7: What is the maximum base-emitter voltage for the MMBT5551?
A7: The maximum base-emitter voltage (Vbe) for the MMBT5551 is 5V.
Q8: What is the maximum collector-emitter voltage (Vce) for the MMBT5551?
A8: The maximum collector-emitter voltage (Vce) is 80V.
Q9: What is the maximum collector-base voltage for the MMBT5551?
A9: The maximum collector-base voltage (Vcb) is 80V.
Q10: Can the MMBT5551 be used as a switching transistor?
A10: Yes, the MMBT5551 can be used as a switching transistor in low-power circuits.
Q11: What is the typical application for the MMBT5551?
A11: The MMBT5551 is used in general-purpose switching and amplification, such as in audio circuits, low-power digital systems, and control circuits.
Q12: What is the base threshold voltage for the MMBT5551?
A12: The base-emitter threshold voltage is typically around 0.7V.
Q13: What is the packaging type of the MMBT5551?
A13: The MMBT5551 comes in the TO-92 package.
Q14: How do I connect the MMBT5551 in a switching circuit?
A14: In a switching circuit, the emitter is connected to ground, the collector is connected to the load, and the base is driven by the control signal, typically through a current-limiting resistor.
Q15: What is the lead length for the MMBT5551?
A15: The lead length of the MMBT5551 is typically 3.4mm.
Q16: Can I use the MMBT5551 in high-power applications?
A16: The MMBT5551 is not suitable for high-power applications due to its power dissipation limit of 500mW.
Q17: What is the typical saturation voltage of the MMBT5551?
A17: The typical saturation voltage (Vce(sat)) for the MMBT5551 is 0.2V.
Q18: What is the thermal resistance of the MMBT5551?
A18: The thermal resistance of the MMBT5551 is 250°C/W for junction-to-ambient.
Q19: How does the MMBT5551 behave at high temperatures?
A19: The MMBT5551 can operate in temperatures up to 150°C, but higher temperatures may cause performance degradation.
Q20: What is the typical switching time for the MMBT5551?
A20: The typical switching time (rise and fall time) is less than 100ns.
Conclusion:
The MMBT5551 is a general-purpose NPN transistor suitable for low-power switching and amplification applications. It comes in the TO-92 package and has three pins: Collector, Base, and Emitter. The detailed pin functions are provided above, and the FAQ section should give you a clear understanding of common concerns.
