NXP BZV55-C11 Zener Diode: Key Specifications and Application Circuits
The NXP BZV55-C11 is a widely utilized Zener diode, belonging to the BZV55 series of small plastic, surface-mount (SOD-80) voltage regulator diodes. Renowned for its reliability and compact form factor, this component is essential in numerous electronic circuits where stable voltage reference or regulation is required.
Key Specifications
The BZV55-C11 is designed to provide a nominal Zener voltage (Vz) of 11V at a specified test current (IZT) of 5 mA. This is its most critical parameter, defining its primary role in a circuit. Other vital specifications include:
Power Dissipation (Ptot): The device can dissipate 500 milliwatts at an ambient temperature of 50°C. This rating is crucial for ensuring the diode operates within its safe thermal limits.
Zener Impedance (ZZT): At the test current of 5 mA, the typical dynamic impedance is a low 10 ohms. A lower impedance signifies better voltage regulation performance under varying load conditions.
Reverse Leakage Current (IR): This is typically less than 100 nA at a voltage of 8 V, which is significantly below the Zener voltage, indicating high quality and low leakage in the off-state.
Temperature Coefficient: The temperature coefficient of the Zener voltage is typically around +7 mV/°C, which is important for applications operating across a wide temperature range.
Application Circuits
The primary function of the BZV55-C11 is to maintain a constant voltage across its terminals. Here are two fundamental application circuits:
1. Basic Voltage Regulator:
This is the most straightforward application. The Zener diode is placed in reverse bias across the load (RL) it is intended to regulate. A series current-limiting resistor (RS) is mandatory. Its value is calculated based on the input voltage (VIN) and the desired Zener current (IZ), ensuring IZ is between IZK (knee current) and IZM (maximum current) to maintain regulation without exceeding power limits. This simple circuit provides a stable 11V reference for low-current loads.
2. Overvoltage Protection Clamp:
In this configuration, the BZV55-C11 is used to protect a sensitive input pin (e.g., on a microcontroller or IC) from voltage spikes that exceed its maximum rating. The Zener diode is connected between the signal line and ground. Under normal operation (voltages below 11V), the diode presents a high impedance and does not conduct. If a transient voltage spike pushes the signal above 11V, the Zener diode conducts, clamping the voltage to just above 11V and shunting the excess current to ground, thereby protecting the downstream component.
ICGOODFIND: The NXP BZV55-C11 is a highly efficient and compact solution for precision voltage regulation and transient protection in space-constrained, modern electronics. Its well-defined characteristics make it an excellent choice for creating stable reference voltages, protecting sensitive ICs, and serving as a fundamental building block in power supply sub-circuits.
Keywords:
Voltage Regulation
Zener Voltage
Overvoltage Protection
Surface-Mount Device (SMD)
Voltage Clamp
