1. Ivan Perić University of Heidelberg Germany
DCDEMC
Ivan Perić
University of Heidelberg
Germany

2. Future developments The present system is based on DCD and DHP
DEPFET output signal consists to 80% of pedestal dispersion and 20% of particle signal
To reduce amount of dispersion, offset DAC is used in DCD
ADC signal has in best case equal amount of particle signal and dispersion
DHP tasks:
1 Particle signal processing
2 Offset correction
Offset DAC memory in DHP
Digital offset correction in DHP
MIP signal 50%
Pedestal dispersion 50%
Zero suppression
Lossless data transfer
Frame memory
MIP signal 20%
Pedestal dispersion 80%
DHP
8 bit
Memory
2 bit
Memory

3. Future developments
In the case of lower readout speed, double sampling in DCD can be used to reduce pedestal dispersion
DHP tasks:
Mainly particle signal processing
MIP signal >95%
Zero suppression
Lossless data transfer
Frame memory
MIP signal 20%
Pedestal dispersion 80%
DHP
8 bit
Memory
Double sampling

4. Future developments
For higher speed we can store offset correction bits on DCD and use a high resolution DAC
The signal entering the amplifier consists mostly on particle signal
Easy implementation of non linear amplifier is wide dynamic range is requires
DHP tasks:
Mainly particle signal processing
DCD is reused for all applications
DHP is redesigned for every particular application, depending on the needs
MIP signal > 95%
Zero suppression
Lossless data transfer
Frame memory
MIP signal 20%
Pedestal dispersion 80%
DHP
8 bit
Memory
Memory
8 bit

5. Amplifier with non linear response
For applications with signals in wide range, non linear amplifier is better
High gain for weak signals, low gain for strong signals
Important: such a circuit works only if the input is free from pedestal dispersion
The most flexible solution: use a high resolution DAC for the pedestal correction
1.1V LP
8b DAC

6. Response to signals 10nA to 200uA…

7. Response to signals 10nA to 200uA…

8. Response to signal 1u, after the LP…

9. Noise summary
Noise 0.34mV, response to 1uA is 30mV, noise corresponds to about 10nA

10. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier

11. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
After gate on
Pedestal and signal

12. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
Sample taken
Pedestal and signal

13. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
After clear
Pedestal

14. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
After clear
Pedestal
Stored current flows in the amplifier

15. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
High gain for weak signal
Pedestal

16. DS amplifier with non linear response
Double sampling can be used as well to produce pedestal free signal for the non linear amplifier
Lower gain for strong signal
Pedestal