To improve read noise of CCD
Tiptilt dewar cooled and on light box connected to astromed 3200 controller and using cicada to readout CCD. Shutter cable connected to control shutter. Version 1.12 of CCD2_TTT64x128 of risc code and chardware.cnf used. RISC code modified to allow the use of cicada and the shutter.
Chardware.cnf setup is as follows
DLOAD=0 # CCD output=0 / Dummy load=1 was 1
DACON=1 # Switches DACs on (=1)
SLOW=0 # Slow(=1) or fast (=0) clock rise & fall times
TC1=4.7 # Time constants for the integrator in us.
TC2=9.4
TC3=14.1
TC=2 # Time constant (1=4.7, 2=9.4, 3=14.1 us) 3
FEG=13.75 # Front End Gain (fixed by the hardware)
PGAIN=4 # Programmable gain (1, 2, 4, 8, 16) 4
CCDI=95 # Initial value of CCDI
BLKLVL=0 # Black level 0-minimum, 1-middle, 2-max
BITWT=125 # ADC Bit Weight in uV/lsb
CCDS=64
CCDP=64
#
# Bias settings in volts. min value -12.8, max value +12.7
# Except VOD: min value +2.0, max value +25.0
#
VOD=17.50 # VDDc VSSL-
VOG=-3.50 # VLGc originally specified as -6.5V by C Mackay
# GK set it at -2.5 now -3.5 for science array to have a
# workable VRSPH
VRBG=12.5 # not used
VRD=9.00 # VODc VSSL- was +9V
VABG=-4.50 # connected to unsued parallel registers
VABD=-4.50 # not used
VSSH=-4.50 # high value for flush
VSSL=-4.50 # low value for readout: normal setting
VSS=-4.50 # low value for readout: normal setting
# IDS in mA. min value 0.0, max value 2.9
IDS(uA)=1.2
#
# Clock settings in volts. min value -12.7, max value +12.8
#
VROL=-8.50 # serial low -8.5
VROH=1.50 # serial high 1.5
VRSPL=-4.50 # reset low -8.2
VRSPH=4.0 # reset high at 1.5V slope across image, set at 3.5V for
# science array. Up to 4.0 to remove image smearing
VIML=-12.50 # parallel low
VIMH=1.00 # parallel high
VSTOH=1.00 # not used
VTHERM=220.00 # regulate ccd temp to
USER=0.00 # not used - analogue output
Read noise and gain for various pgain, tc, CCDI
|
pgain |
tc |
CDDI |
Gain [e/ADU] |
Noise [e] |
Bias SD |
|
4 |
2 |
95 |
1.264 |
8.9 |
7 |
|
4 |
3 |
95 |
1.85 |
9.6 |
5 |
|
8 |
3 |
95 |
1.02 |
45 |
42 |
|
8 |
2 |
95 |
0.69 |
52 |
81 |
|
2 |
2 |
95 |
2.58 |
11.1 |
4.5 |
|
2 |
3 |
95 |
3.56 |
11.8 |
3.0 |
|
4 |
2 |
190 |
0.614 |
8.5 |
15.0 |
|
4 |
3 |
190 |
0.986 |
7.5 |
7.4 |
|
8 |
3 |
190 |
0.509 |
50 |
100 |
Investigate varying reset gate lower level voltage
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.938 |
7.1 |
|
-8.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.973 |
8.4 |
|
-2.0V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.979 |
7.5 |
|
-2.0V |
+6.0V |
-8.5 |
1.5 |
17.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.011 |
9.09 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
18.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.961 |
7.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
19.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.936 |
8.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
16.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.1 |
7.7 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
15.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.019 |
6.8 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
14.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.977 |
6.1 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
10V |
-3.5V |
1.20 |
4 |
3 |
190 |
2.0 |
8.4 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
8.5V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.057 |
108 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
8.75V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.991 |
9.1 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
8.9V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.021 |
7.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.0V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.036 |
7.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.1V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.94 |
6.7 |
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.92 |
6.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.3V |
-3.5V |
1.20 |
4 |
3 |
190 |
0.95 |
6.4 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.4V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.05 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.4V |
-3.5V |
1.20 |
4 |
3 |
190 |
1.3 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
0.10 |
4 |
3 |
190 |
1.01 |
12.1 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
0.20 |
4 |
3 |
190 |
1.09 |
9.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
0.50 |
4 |
3 |
190 |
1.05 |
7.9 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
0.80 |
4 |
3 |
190 |
1.05 |
7.4 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.0 |
4 |
3 |
190 |
1.0 |
7.1 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.958 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.5 |
4 |
3 |
190 |
0.952 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
2.0 |
4 |
3 |
190 |
0.94 |
7.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-8.5V |
1.2 |
4 |
3 |
190 |
0.99 |
7.0 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-6.5V |
1.2 |
4 |
3 |
190 |
0.95 |
6.5 |
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-5.0V |
1.2 |
4 |
3 |
190 |
0.95 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.93 |
6.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.0V |
1.2 |
4 |
3 |
190 |
1.00 |
7.1 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-2.0V |
1.2 |
4 |
3 |
190 |
0.96 |
49 |
|
-4.5V |
+4.0V |
-4.5 |
4.0 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.92 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
4.0 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.048 |
8.1 |
|
-4.5V |
+4.0V |
-8.5 |
2.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.04 |
7.2 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.96 |
6.7 |
|
-4.5V |
+4.0V |
-8.5 |
0.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.98 |
6.8 |
|
-4.5V |
+4.0V |
-8.5 |
-0.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.003 |
6.9 |
|
-4.5V |
+4.0V |
-8.5 |
-1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.968 |
6.5 |
|
-4.5V |
+4.0V |
-8.5 |
-2.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.994 |
7.1 |
|
-4.5V |
+4.0V |
-8.5 |
-3.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.016 |
6.8 |
|
-4.5V |
+4.0V |
-8.5 |
-5.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
3.5 |
23 |
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.998 |
6.9 |
|
-4.5V |
+4.0V |
-6.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.998 |
6.9 |
|
-4.5V |
+4.0V |
-4.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.024 |
6.9 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
360 |
0.58 |
15.7 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
280 |
0.7 |
9.9 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
235 |
0.78 |
6.8 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
210 |
0.91 |
7.0 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.944 |
6.7 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
150 |
1.164 |
7.0 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
120 |
1.517 |
8.4 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
200 |
0.98 |
6.8 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
180 |
1.053 |
7.01 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
190 |
0.614 |
9.4 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
150 |
0.887 |
8.9 |
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
120 |
1.031 |
7.9 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
100 |
1.2 |
8.5 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
110 |
1.035 |
7.7 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
2 |
130 |
0.964 |
7.6 |
|
-3.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.986 |
7.0 |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.918 |
6.4 |
|
-4.0V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.918 |
6.4 |
|
-5.0V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
1.003 |
7.1 |
The best setup seems
|
VRSPL |
VRSPH |
VROL |
VROH |
VOD |
VRD |
VOG |
IDS [uA] |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
|
-4.5V |
+4.0V |
-8.5 |
1.5 |
17.5V |
9.2V |
-3.5V |
1.2 |
4 |
3 |
190 |
0.918 |
6.4 |
The next thing to try is to vary settling times
|
reset settling |
serial settling |
reset high time |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
Comments |
|
30 |
28 |
10 |
4 |
3 |
190 |
0.969 |
6.6 |
|
|
60 |
28 |
10 |
4 |
3 |
190 |
1.01 |
6.9 |
|
|
10 |
28 |
10 |
4 |
3 |
190 |
1.036 |
6.5 |
|
|
30 |
60 |
10 |
4 |
3 |
190 |
0.971 |
6.7 |
|
|
30 |
28 |
0 |
4 |
3 |
190 |
|
|
image saturates |
|
60 |
28 |
4 |
4 |
3 |
190 |
0.92 |
4.5 |
reset high done after rdadc in readpx rather than before and reset low done at start of readpx |
|
30 |
28 |
4 |
4 |
3 |
190 |
0.98 |
5.0 |
reset high done after rdadc in readpx rather than before and reset low done at start of readpx |
|
60 |
28 |
4 |
4 |
3 |
190 |
0.98 |
4.4 |
reset high, resetdwell and reset low grouped together and placed after rdadc in readpx also removed serial binning in serxfer to reduce code size |
|
60 |
28 |
4 |
4 |
3 |
190 |
0.999 |
4.6 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
|
60 |
28 |
11 |
4 |
3 |
190 |
0.974 |
7.1 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
|
60 |
28 |
2 |
4 |
3 |
190 |
1.016 |
4.0 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size. Flat field has 30000 counts rather than 10000. Probably is not resetting properly. |
|
60 |
28 |
4 |
4 |
3 |
190 |
0.971 |
4.4 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size. Flat look ok. Need to try with star test pattern. |
|
60 |
28 |
6 |
4 |
3 |
190 |
0.938 |
4.5 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
|
60 |
28 |
8 |
4 |
3 |
190 |
0.927 |
6.8 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
|
60 |
28 |
6 |
4 |
3 |
190 |
0.958 |
6.2 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size. Serxfer broken up into two part. As much serial clocking is done before integrate on reset as possible and only dump charge is done for integrate on signal. |
|
24 |
28 |
6 |
4 |
3 |
190 |
0.925 |
4.5 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
The best setup seems
|
reset settling |
serial settling |
reset high time |
pgain |
tc |
CDDI |
Gain [e/ADU] |
RN [e] |
Comments |
|
24 |
28 |
6 |
4 |
3 |
190 |
0.925 |
4.5 |
reset high, resetdwell and reset low grouped together and placed before rdadc in readpx also removed serial binning in serxfer to reduce code size |
Modified RISC code, mso-cs.h, and chardware.cnf checked into CVS as version 1.13
To get rid of first line affect by changing delays before first pixel of each line is read.
Checked out modified RISC code, mso-cs.h, and chardware.cnf version 1.13. Tiptilt software ran on madras at MSO. Astromed 3200 controller connected to moriarity-sso at SSO. Tiptilt dewar 2 mounted on test box with star test pattern. Environment variable ASTROMED_3200_DIR set to /priv/mephisto/mark/cicada/ccd_config/astromed_3200. Ran cicada to set its configuration information to use moriarity-sso.
Start tiptilt as follows
In RISC code, mso-cs.h V1.13, changed delays in rdfullrw3 from
define(rdfullrw3, --RDFULLRW read out full serial o/p register
cffpx($1,CS)
rstccdhigh
rsthidwell
rstccdlow
delay 200
rstccdhigh
rsthidwell
rstccdlow
delay 3
rdactpx($2,CRD)
cffpx($3,CF)
)dnl
to the following
define(rdfullrw3, --RDFULLRW read out full serial o/p register
cffpx($1,CS)
rstccdhigh
rsthidwell
rstccdlow
delay 454 -- increase from 200 to 454 for extra delays
rstccdhigh
rsthidwell
rstccdlow
delay 19 -- increased from 3 to 19 for rdadc delay
rdactpx($2,CRD)
cffpx($3,CF)
)dnl
This successfully has got rid of the first line affect in subimage readout.
However during operation, the line reappears, then the rdadc delay (ie delay
19) should be adjusted by a few counts.
Please send any additions and comments to:
page maintainer, mark@mso.anu.edu.au
Last Modified : Tue, 4 Nov 1997