1. HEC Electronics Chain HEC chain-2000 Spice model Analytical model
HECPAS Review MPI Feb
L. Kurchaninov
HEC Electronics Chain
HEC chain-2000
Spice model
Analytical model
Spice vs. Analytics
HEC chain-2010
PA Spice model
Validation tests
HEC mock-up

2. MiniFCAL, TRIUMF 31 Oct. 2008
L. Kurchaninov
HEC Chain-2000

3. MiniFCAL, TRIUMF 31 Oct. 2008
L. Kurchaninov
Spice Model
All active components are Laplace functions with parameters taken from measurements
Two models: for warm and for cold
A number of versions: beam tests, ATLAS
Cables are “lossy”, but frequency independent
Spice is used as a numerical calculator to generate waveforms
Model was used to
study effects of various components to signal shape and amplitude (e.g. strip line stray capacitance, decoupling caps, etc.)
Cross-check analytical model

4. HECPAS Review MPI Feb
L. Kurchaninov
Analytical Model
ATLAS HEC Note-109 Modeling of the HEC Electronics Chain wwwatlas.mppmu.mpg.de/HEC/notes.html
Model functions are pole-zero combinations (in s-domain)
Skin effect in cables is approximated by 1Z-2P function
Model adjustable to reproduce shapes within ±1%
Used for signal reconstruction in beam tests

5. + - Spice vs. Analytics Feature Spice Analytic Detail description
HECPAS Review MPI Feb
L. Kurchaninov
Spice vs. Analytics
Feature
Spice
Analytic
Detail description + -
Reflections
Skin effect
Noise calcs

6. HEC Chain-2010 Faster timing requires better models
HECPAS Review MPI Feb
L. Kurchaninov
HEC Chain-2010
Faster timing requires better models
Both models are useful:
SPICE: detail modeling, debugging, failures
Analytic: signal reconstruction functions and algorithms
Important for analytics
Better cable model
Important for Spice
Skin-effect in cables: not trivial up to my knowledge
HEC impedance Xtalk leak and shapes
Noise calculations: to xcheck analytic model

7. GaAs Spice Model Was missing for GaAs PA. First built then modeled
HECPAS Review MPI Feb
L. Kurchaninov
GaAs Spice Model
Was missing for GaAs PA. First built then modeled
Make sense before production starts
Do we need full Spice?
Transfer function vs. in/out load, LV, …
Oscillations margin
Power vs. signal rate
Warm-cold performance
Identify causes of radiation degradation
Could be time and manpower consuming

8. HECPAS Review MPI Feb
L. Kurchaninov
Validation Tests
Design stage requires various tests, sometime beyond actual practical needs
All lab tests at design stage (1996) were done up to “board level” with cable-capacitance input load. OK to validate design, not enough to validate system. System tests done with preproduction batch
Was not tested in (and not tested up to date):
Response vs. signal rate estimations show no effect for LHC
Shape vs. amplitude at 0.1% level done later with calib pulses at 1% level
Full-range temperature dependence mostly of academic interest

9. HECPAS Review MPI Feb
L. Kurchaninov
HEC Mock-up
Measurements of transfer function and noise at ~ns shaping requires actual input load. Can be done with a mockup
To cover full range of HEC cable length and Cd
To represent HEC shielding and grounding