3ffm2 fhi 1mhz flo 1hz flo 1year eecs 240 lecture 5

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Unformatted text preview: d the input gate noise due to Rg EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 16 1/f Noise • Flicker noise – Kf,NMOS = 2.0 x 10-29 AF Kf,PMOS = 3.5 x 10-30 AF – Strongly process dependent (also model) • Example: ID = 10µA, L = 1µm, – Cox = 5.3fF/µm2, fhi = 1MHz flo = 1Hz flo = 1/year EECS 240 Lecture 5: Noise 722pA rms 1082pA rms © 2006 A. M. Niknejad and B. Boser 17 1/f Noise Corner Frequency • Definition (MOS) K f I D ∆f = 4k BTr γg m ∆f 2 L Cox f co f co = = K f ID 1 4k BTr γg m L2Cox Kf 4k BTr γCox 11 L2 g m I D Kf • Example: – V* = 200mV, V* = 8k BTr γCox L2 γ=1 L = 0.35µm L = 1.00µm EECS 240 Lecture 5: Noise NMOS 192kHz 24kHz PMOS 34kHz 4kHz © 2006 A. M. Niknejad and B. Boser 18 SPICE Noise Analysis 100/1 50/2 Slope … 1000/10 EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 19 Noise Calculations • Output spectral noise density • Method: 1) 2) 3) 4) Small-signal model All inputs = 0 (linear superposition) Pick output vo or io For each noise source vx, ix Calculate Hx(s) = vo(s) / vx(s) (… io, ix) 5) Total noise at output is 2 2 von ,T ( f ) = ∑ H x ( s ) s =2πjf v x ( f ) 2 x simpler notation : 2 von ,T ( f ) = Sn ( f ) • Tedious but simple … EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 20 Example: Common Source EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 21 Simulation Result EECS 240 Lecture 5: Noise © 2006 A. M. Niknejad and B. Boser 22...
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This note was uploaded on 03/18/2014 for the course EECS 240 taught by Professor Boser during the Spring '04 term at Berkeley.

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