KDZTR33B Discrete Semiconductor Products

A KDZTR33B is a Zener single diode designed for use in general-purpose voltage regulation and voltage clamping applications. As such, it is often employed in stabilizing or constraining the current or voltage in a circuit.

The KDZTR33B diode operates in a breakdown mode, in which it begins to conduct current when a certain reverse voltage is applied; this breakdown voltage is called the Zener voltage. Once this voltage is reached, the device begins to regulate the voltage at the applied value and can be used for voltage regulation, or for providing a stable reference voltage for other stages of a circuit.

The KDZTR33B is a very useful device in power supplies and voltage regulators, allowing for constant-voltage operation even in the presence of varying input/load current, ripple, and power losses. It may be also used in non-regulated power supplies, as a voltage reference, and as a voltage clamp in RF applications.

The working principle of the KDZTR33B is illustrated in figure 1. The Zener diode consists of regions of high doping on either side of a lightly doped intrinsic layer. Under normal operation, holes and electrons injected into the intrinsic layer recombine quickly, keeping the diode in a reverse-bias state. However, when the reversed bias voltage reaches the breakdown voltage, V_Z, avalanche current begins to flow.

Avalanche current occurs when an electric field within the junction strengthens until such a point that the electric field can no longer be held back. This causes majority carriers in the intrinsic region to experience energetic collisions, which then results in the emission of more minority carriers in the intrinsic region. This process continues, creating a multitude of carriers that current flow through the diode. When avalanche current passes through the diode, the voltage drop across the diode remains constant at the Zener voltage.

An important function of a Zener diode is its ability to limit the maximum current which can flow through it in the reverse-bias direction. The purpose of the current-limiting ability is to ensure that the voltage remains at the Zener voltage. If the current-limiting capability is exceeded, the results could be catastrophic, potentially leading to destruction of the diode itself or destruction of other components in the system.

The KDZTR33B device is available in a DO-213 package, and its specifications include a power dissipation of 500mW, a voltage of 33V, a maximum current of 5mA, and a temperature range of -55°C to +125°C. Figure 2 shows a graphical representation of the device in the environment it would be typically used in.

Ultimately, the KDZTR33B diode can be used for a variety of voltage regulation and voltage clamping applications. The device has a low dynamic resistance and is able to offer a very stable Zener voltage, making it an attractive choice for many applications. Additionally, the device is able to provide stable operation even in noisy environments and can help to ensure that the desired voltage is maintained in a circuit.