Question

VK =0,4k Figure 1: Schematic (left) and equivalent circuit (right) of a hypothetical BJT-based device. 5. Two BJTs are conneted as indicated in Figure 1. Sketch the expected IV characteristics. (IA VS. VA for different values of IG) (10 pts) (a) Explain the operation of this device in detail. (b) Sketch the anticipated IV characteristics (IA vs VA) for different values of Ig.

Answer 1

Forward Voltage drop S Forward Current IA Cuvent. 14--Formayd conductim Region di curven with de curent Tuz With tak current the As with nohate Current. IVERO - Forward voltage Forward Blocking Region Reverse current Avalanche Breakdown VFBoo Fornard break over voltage VRBO & Reverse breakower V-I characteristics of scR A graph between anode-cathale voltage (V) and anode current I at constant gate current if called v-I Characteristics of an ser. +(1) Forward Characteristics : The curve he I when forklard voltage is applied (a) When trake current is rew: Aptle voltage ip Increased from zero (with zero bake current), Here is a small Leackage current which flow throw anode. This is due to leackage of minority Carriers through Junction Is this trackage current also flow throw Load this small leackage current does not affect the lood at all and for all practical purpose, the Load is considered to be off. Now, When the power supply voltage, which is equal to voltage drop acrope anode and Cathoden of ser reached the forward breakover voltage SCR at once begain to conduct and the voltage N across the the ristor suddenly drop ap Shown by doitted curre AB. Full conduction is reached rapidly under such conditions, The SCR NOW act as close circuit.

VA GJIA OVA SILI IA to NONI 6 AIK VKEO This is equivalent circuit of an sch contains two transistors one of them is pnp and other one is npn connected with each other. The collector of transistor al drives the base of transistor P2, and the collector of Q2 drived the bage of Ph. There - connection provided the positive feedback also called regeneration. A Terminal is drawn from the base of Transitor la called Gate. A Triggeering pulse in this case current source is applied to the Gate to bring the SCR in on state,

VA GJIA OVA SILI IA to NONI 6 AIK VKEO This is equivalent circuit of an sch contains two transistors one of them is pnp and other one is npn connected with each other. The collector of transistor al drives the base of transistor P2, and the collector of Q2 drived the bage of Ph. There - connection provided the positive feedback also called regeneration. A Terminal is drawn from the base of Transitor la called Gate. A Triggeering pulse in this case current source is applied to the Gate to bring the SCR in on state,