Electrical verification of the top level bias block

To run all simulations do “make all”

Loop stability analysis (lstb)

Uses Tian/Middelbrook to check the phase-margin of the RPLY_BIAS circuit

Name Parameter Description   Min Typ Max Unit
Bandwidth f3db   Spec 1.000 3.000 15.000 kHz
      Sch_typ   3.816    
      Sch_etc 1.900 4.396 12.638  
      Sch_std 3.644 3.814 3.983  
Gain Margin gm_db   Spec -50.00 -10.00 -10.00 dB
      Sch_typ   -19.62    
      Sch_etc -23.71 -20.00 -16.95  
      Sch_std -20.16 -19.62 -19.08  
DC gain lf_gain   Spec 35.00 40.00 55.00 dB
      Sch_typ   49.33    
      Sch_etc 35.56 48.79 49.99  
      Sch_std 48.96 49.35 49.74  
Phase Margin pm_deg   Spec 45.00 60.00 90.00  
      Sch_typ   76.95    
      Sch_etc 72.62 77.23 80.72  
      Sch_std 75.92 76.85 77.78  
Unity Gain Frequency ug   Spec 0.50 1.00 10.00 MHz
      Sch_typ   1.15    
      Sch_etc 0.53 1.07 1.78  
      Sch_std 1.06 1.15 1.24  
PMOS gate v(lpo)   Spec 0.45 0.70 1.10 V
      Sch_typ   0.72    
      Sch_etc 0.49 0.74 1.01  
      Sch_std 0.72 0.72 0.73  
Diode voltage v(xdut.vd1)   Spec 0.50 0.70 1.00 V
      Sch_typ   0.75    
      Sch_etc 0.58 0.72 0.85  
      Sch_std 0.75 0.75 0.75  
VD Error vdiff   Spec -6.00 0.00 6.00 mV
      Sch_typ   -0.75    
      Sch_etc -3.65 -1.04 0.88  
      Sch_std -5.49 -0.90 3.68  

Transient analysis (tran)

Check transient operation, and make sure it starts up

Name Parameter Description   Min Typ Max Unit
Delta VD error dvderr   Spec -10.000 0.000 10.000 mV
      Sch_typ   2.651    
      Sch_etc -0.270 3.211 6.951  
      Sch_std -1.388 3.295 7.978  
OTA input offset offset   Spec -10.00 0.00 10.00 mV
      Sch_typ   0.76    
      Sch_etc -1.47 1.04 3.61  
      Sch_std -3.11 1.45 6.01  
Bias current ibp_1u_3   Spec 0.60 0.79 1.20 uA
      Sch_typ   0.79    
      Sch_etc 0.61 0.81 1.01  
      Sch_std 0.75 0.79 0.83  
Active current i_active   Spec 18.75 25.00 31.25 uA
      Sch_typ   23.20    
      Sch_etc 18.93 23.70 29.63  
      Sch_std 22.30 23.31 24.31  
Power down current i_pwrdwn   Spec 0.00 25.00 200.00 nA
      Sch_typ   25.62    
      Sch_etc 10.30 50.72 139.89  
      Sch_std 25.41 25.71 26.01  

Temperature sweep (tsweep)

Temperature sweep to check vref accuracy variation with temperature

Name Parameter Description   Min Typ Max Unit
Current at 25C ibp   Spec 0.750 0.790 0.830 uA
      Sch_typ   0.782    
      Sch_etc 0.770 0.780 0.785  
      Sch_std 0.750 0.781 0.813  
Temp Coefficient ibp_nA_c   Spec 1.8 2.3 2.8 nA/C
      Sch_typ   2.3    
      Sch_etc 2.3 2.3 3.7  
      Sch_std 2.0 2.2 2.5  
Temp Coefficient ibp_ppm_c   Spec 2640.0 3000.0 3360.0 ppm/C
      Sch_typ   2910.3    
      Sch_etc 2891.6 2926.3 4752.4  
      Sch_std 2559.3 2871.3 3183.3