XRDAN30 Introduction !"# $% & '' ' % ( $ & )$ $ $ $ ' % )$ ) - -. $ )$ $$* -. • K 1 + S• P1 /01 Figure 2. Equivalent Circuit at Full Scale for AC Analysis % %$ + $ ' & Figures 3, 4 and 5.2& 3) $ & ) ) $ ) 1 The Effect of DAC Output Capacitance +Figure 1.) ' $ ' Figure 2. ( , 4, Gain (dB) - -. -. - Amp Main Pole P1 ,(% +4 2 /01 Figure 3. Op Amp Open Loop Characteristics ,(% +4 2 Figure 1. Typical Configuration CMOS IOUT DAC with External Op Amp forming Voltage Output Configuration R IN 20 Lo g ( ) R IN + Rf Gain (dB) R IN • R f x C O = 1 P2 Figure 4. Feedback Signal Path Transfer Characteristics XRDAN30 4, 5 Gain (dB) 5 $ 5 5 ,(% +4 2 Figure 8. Op Amp Open Loop Characteristics Figure 5. Root Locus ,(% +4 2 $ 6 + 2 )7 $ (Figure 6. and Figure 7.) 1 ' %$ +, 8& 9& ) 3 R IN 20 Lo g ( ) R IN + Rf : +2 5 R IN • R f x (C Z + C O) 6 6 "* Figure 9. Feedback Signal Path Transfer Characteristics - -. -. - /01 5 6 5 Figure 6. Typical Zero Compensation of Co General Pole Figure 10. Root Locus 6 % (Figure 11. and Figure 12.)& ; $' $ ) < 2 1 & $7 $ $ (Figures 13, 14, and 15) 2 1 " & $ $ =2 1 $ $ & $$* + 1 & 2 ;2 * ) $ $& (% - -. -. - • K 1 + S• P1 /01 Figure 7. Equivalent Circuit at Full Scale for AC Analysis XRDAN30 6 ,(% +4 2 20 Lo g ( R IN ) R IN + Rf -. -. - 5 : +2 - R A • R IN • R f x (C Z + C O) 6 "* /01 Figure 14. Feedback Signal Path Transfer Characteristics Figure 11. Typical Zero Compensation of Co General Pole 5 6 6 5 Figure 15. Root Locus - -. -. - • K 1 + S• P1 1 ) % * ) $ (% -. /01 /01 6 Figure 12. Equivalent Circuit at Full Scale for AC Analysis - 4, -. Gain (dB) $ 5 5 -. /01 - - 4 /- Figure 16. Typical Zero Compensation of Co General Pole ,(% +4 2 Figure 13. Op Amp Open Loop Characteristics = 4 XRDAN30 ,%& $% $ % $ ' )% ? 4 1 ) % ) * )7 ( 1 ) ' $ )% 3 $ $ ) Output Loading Effects ,%& ) ' $ (Figure 16.) (% $ 3 ' & 7 $ $ & ! $ ) % ( % & % $ 1 - ' % $ % (' 7 :< % $ - = @ ) & 1 ) )% = A B% 7 C A Practical Example .& % 5D>9 5D@8< 1 5D>9 , 1 5D@8 @ , % E 7& & 5D>9 % ) = @ 5D@8 & 5D>9 B 5D@8C $ $$ > > $ )$ 1 % )7 ' )% 1 - ? $ $ $ % $ .5. ( ;