v {xschem version=3.1.0 file_version=1.2
* Copyright 2021 Stefan Frederik Schippers
* 
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.

}
G {}
K {}
V {}
S {}
E {}
B 2 820 -310 1280 -70 {flags=graph
y1 = -2.3e-14
y2 = 1.9

x1=0
x2=0.0001
divx=5
node="vbg
en_n
start"
color="4 5 9"  unitx=u


divy=8
subdivx=4
subdivy=1
dataset=-1}
B 2 820 -590 1280 -460 {flags=graph
y1 = 1.7008e-05
y2 = 4.36367e-05
divy = 5
unity=u
subdivy=1
x1=0
x2=0.0001
divx=4
subdivx=4
node="\\"Icc;i(vcc)\\""
 unitx=u
color=4
dataset=-1}
P 4 7 930 -390 930 -260 920 -260 930 -240 940 -260 930 -260 930 -390 {fill=true}
P 4 7 1110 -330 1110 -250 1100 -250 1110 -230 1120 -250 1110 -250 1110 -330 {fill=true}
T {Example of Mismatch simulation of a bandgap reference. Variations are generated also on Vcc
Plot shows bandgap varying outputs before and after the offset cancellation.} 10 -720 0 0 0.4 0.4 {}
T {Select one or more graphs (and no other objects)
and use arrow keys to zoom / pan waveforms} 290 -580 0 0 0.3 0.3 {}
T {Bandgap voltage after offset compensation} 950 -350 0 0 0.3 0.3 {layer=4}
T {Bandgap voltage before offset compensation} 820 -410 0 0 0.3 0.3 {layer=4}
N 240 -340 240 -320 { lab=EN_N}
N 650 -340 650 -320 { lab=#net1}
N 390 -340 390 -320 { lab=VSS}
N 240 -220 240 -200 {lab=TEMPERAT}
N 390 -220 390 -200 { lab=START}
N 650 -220 650 -200 { lab=CLK}
N 240 -460 300 -460 {
lab=EN_N}
N 240 -440 300 -440 {
lab=VCC}
N 240 -420 300 -420 {
lab=VSS}
N 240 -500 300 -500 {
lab=START}
N 240 -480 300 -480 {
lab=CLK}
C {devices/code.sym} 10 -450 0 0 {name=NGSPICE
only_toplevel=true
value="
* this experimental option enables mos model bin 
* selection based on W/NF instead of W
.options wnflag=1 XMU=0.49 METHOD=GEAR ITL4=100 CHGTOL=1e-15 TRTOL=1 RELTOL=0.0001 VNTOL=0.1u
.param ABSVAR=0.03
.param VCCGAUSS=agauss(1.8, 'ABSVAR', 1)
.param VCC=VCCGAUSS
* .param VCC=1.8
** variation marameters:
* .options savecurrents
.control
  option seed=12
  let run=1
  dowhile run <= 30
    if run > 1
      reset
      set appendwrite
    end
    * save all
    if run % 3 = 1
      set temp=-40
    end
    if run % 3 = 2
      set temp=27
    end
    if run % 3 = 0
      set temp=125
    end
    tran 0.05u 100u
    write tb_bandgap.raw
    let run = run + 1
  end
  set nolegend
  plot all.vbg
.endc
" }
C {devices/title.sym} 160 -30 0 0 {name=l1 author="Stefan Schippers"}
C {sky130_tests/bandgap.sym} 450 -460 0 0 {name=x1}
C {devices/lab_pin.sym} 600 -500 0 1 {name=p1 lab=VBG}
C {devices/lab_pin.sym} 240 -460 0 0 {name=p2 lab=EN_N}
C {devices/vsource.sym} 240 -290 0 0 {name=V1 value=0}
C {devices/lab_pin.sym} 240 -340 0 1 {name=p3 lab=EN_N}
C {devices/vsource.sym} 650 -290 0 0 {name=V2 value="pwl 0 0 1u 0 4u VCC"}
C {devices/lab_pin.sym} 650 -400 0 0 {name=l29 sig_type=std_logic lab=VCC}
C {devices/lab_pin.sym} 240 -440 0 0 {name=p4 lab=VCC}
C {devices/lab_pin.sym} 240 -420 0 0 {name=p5 lab=VSS}
C {devices/vsource.sym} 390 -290 0 0 {name=V3 value=0}
C {devices/lab_pin.sym} 390 -340 0 1 {name=l3 sig_type=std_logic lab=VSS}
C {devices/lab_pin.sym} 240 -260 0 0 {name=l2 sig_type=std_logic lab=VSS}
C {devices/lab_pin.sym} 650 -260 0 0 {name=l4 sig_type=std_logic lab=VSS}
C {devices/lab_pin.sym} 390 -260 0 0 {name=l5 sig_type=std_logic lab=0}
C {devices/launcher.sym} 200 -90 0 0 {name=h2 
descr="Simulate" 
tclcommand="xschem netlist; xschem simulate"}
C {devices/vsource_arith.sym} 240 -170 0 0 {name=E5 VOL=temper MAX=200 MIN=-200}
C {devices/lab_pin.sym} 240 -220 0 1 {name=p113 lab=TEMPERAT}
C {devices/lab_pin.sym} 240 -140 0 0 {name=p114 lab=VSS}
C {devices/vsource.sym} 390 -170 0 0 {name=V4 value="pwl 0 VCC 25u VCC 25.001u 0"}
C {devices/lab_pin.sym} 390 -220 0 1 {name=p7 lab=START}
C {devices/lab_pin.sym} 390 -140 0 0 {name=l21 sig_type=std_logic lab=VSS}
C {devices/vsource.sym} 650 -170 0 0 {name=V5
value1="dc 0 "
value="dc 0 pulse 
+ VCC 0 
+ 25u
+ 1n 1n 
+ 27000n 30000n"
}
C {devices/lab_pin.sym} 650 -140 0 0 {name=l6 sig_type=std_logic lab=VSS}
C {devices/lab_pin.sym} 650 -220 0 1 {name=p6 lab=CLK}
C {devices/lab_pin.sym} 240 -500 0 0 {name=p8 lab=START}
C {devices/lab_pin.sym} 240 -480 0 0 {name=p9 lab=CLK}
C {devices/launcher.sym} 365 -625 0 0 {name=h1 
descr="Select arrow and 
Ctrl-Left-Click to load/unload waveforms" 
tclcommand="
xschem raw_read $netlist_dir/[file tail [file rootname [xschem get current_name]]].raw tran
"
}
C {sky130_fd_pr/corner.sym} 20 -270 0 0 {name=CORNER only_toplevel=true corner=tt_mm}
C {devices/spice_probe.sym} 600 -500 0 0 {name=p10 attrs=""}
C {devices/spice_probe.sym} 300 -500 0 1 {name=p11 attrs=""}
C {devices/spice_probe.sym} 300 -480 0 1 {name=p12 attrs=""}
C {devices/spice_probe.sym} 300 -460 0 1 {name=p13 attrs=""}
C {devices/spice_probe.sym} 300 -440 0 1 {name=p14 attrs=""}
C {devices/spice_probe.sym} 300 -420 0 1 {name=p15 attrs=""}
C {devices/spice_probe.sym} 240 -220 0 1 {name=p16 attrs=""}
C {devices/ammeter.sym} 650 -370 2 0 {name=VCC}