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Introduction

A diode might even be statuesque in SPICE by a diode statement in conjunction with a model statement. The diode statement specifies the diode name, the nodes to that the diode is connected, and its model name. The model incorporates associate intensive vary of diode characteristics like DC and small-signal behavior, temperature dependency, and noise generation. The model parameters take into thought temperature effects, various capacitances, and physical properties of semiconductors.

Diode Model

The SPICE model for a reverse-biased diode is shown in Fig-1. The small-signal and static models that area unit generated by SPICE area unit shown in Fig- a combine of and three, severally. among the static model, the diode current, that depends on its

voltage is portrayed by current provide. The small-signal parameters area unit generated by SPICE from the operating purpose. SPICE generates a complicated model for diodes. The model equations that area unit utilised by SPICE area unit depicted in Refs. [1,2]. In many cases, significantly the number at that this book is aimed, such sophisticated models aren’t necessary. many model parameters area unit typically unobserved by the users, and SPICE assigns default values to the parameters.

DIODE STATEMENT

The name of a diode should begin with D, and it takes the overall type

Your conDiode image and model parameters: wherever metal and NK area unit the anode node and thus the cathode node, severally. this flows from anode node metal through the diode to cathode node NK. DNAME is that the model name. The PSpice schematic of a diode with a model name Dbreak is shown within the image. The EVAL library of the PSpice student version supports few low-power diodes, like D1N4002, D1N4148, and D1N914. However, the user can change the model parameters of a D-break device. Click the proper push to open the window Edit PSpice Model as shown in Figure seven.4b. The model name can also be changed. The break devices area unit on the market from the break Library.tent goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.

Diode Characteristics:

The typical V–I characteristic of a diode is shown. The characteristic will be expressed by AN equation referred to as the Schockley diode equation, given by

where
Is = run (or reverse saturation) current, usually within the vary 10−6 to 10−20 A.
VD = diode voltage with anode positive with relation to cathode V.

ID = current through the diode, A.

n = empirical constant is thought because the emission constant (or quality factor),
whose worth varies from one to two.