Lect. 13: High-Frequency Model of MOSFET (4.8)
Lect. 13: High-Frequency Model of MOSFET (4.8)
Lect. 13: High-Frequency Model of MOSFET (4.8)
- No tags were found...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Lect</strong>. <strong>13</strong>: <strong>High</strong>-<strong>Frequency</strong> <strong>Model</strong> <strong>of</strong> <strong>MOSFET</strong>How fast can a <strong>MOSFET</strong> transistor operate?VgsI0= gmVgs − = gmVgs − jωCgdVgs gmVgs ( ∵gm >> ωCgd)1jωC⎛ 1 1 ⎞ 1Vgs = Ii ⋅ || = Ii⋅⎜ jωCgd jωC ⎟⎝gS ⎠ jω( Cgd + Cgs)I g( )0m∴ =Ii jωCgd + Cgs0mFor 1, ωIi Cgd + CgsgmOr fT=(Unit-gain <strong>Frequency</strong>)2 π ( Cgd+ Cgs)How to make <strong>MOSFET</strong> faster?Which is faster NMOS or PMOS?Current state-<strong>of</strong>-the-art NMOS has f Tapproaching 100 GHz.I= =gdgElectronic Circuits 1<strong>High</strong>-Speed Circuits and Systems Laboratory
Change language