Equivalent Circuit Model with Nonlinear Characteristics of ... · Zener Diode Extracted from SPICE...
Transcript of Equivalent Circuit Model with Nonlinear Characteristics of ... · Zener Diode Extracted from SPICE...
Equivalent Circuit Model with Nonlinear Characteristics of Zener Diode
Extracted from SPICE Model for ESD Simulation
M. Aoki,
T. Matsushima, T. Hisakado, O. Wada
Kyoto University, Japan
Outline Equivalent Circuit Model with Nonlinear Characteristics of
Zener Diode Extracted from SPICE Model for ESD Simulation
1. Background
– Predicting immunity of ESD
– ICIM-CPI model
2. Proposal of modeling and approach
– Equivalent circuit model
– Represent nonlinearity of Zener Diodes
3. Simulation
– ESD test simulation
– Results / discussions
4. Conclusion
Background
Predicting immunity of ESD
Background:Electrostatic discharge(ESD) causes errors of ICs due to its high voltage
3
ESD current
Demands:
Predicting the immunity behavior to ESD or pulse disturbance
in the design stage of the devices.
BREAK
Next : Immunity macro model
Equivalent CircuitExpression
SPICE Model Immunity Macro Model
Temperature dependence
Highly confidential
Constructed by external measurement
effective also in the absent of SPICE
ESD protections
Background
Predicting immunity characteristic of ESD
4
Voltage-dependent elements
FB
PPN
VDD1 VDD2
GND1 GND2
T1
T2
T3
[S]Disturbance
Goal: Construction of Equivalent Circuit Model
A
a
Designing ESD protection circuit easily
Simulation in time domain
Using a function approximation
to express nonlinear characteristics
Background
ICIM-CPI model
ICIM-CPI model(Integrated Circuit for IMmunity behavioral
simulation – Conducted Pulse Immunity)
5
Future IEC 62433-6
・Nonlinear behavior of IC: PDN+NLB
・Time-domain simulation
PDN
[S]
ICIM-CI
IB
Freq
...
1.0E+7
2.0E+7
PT
15.2
17.8
VOUT
5.1
5.11
T1
T2
GND1
T3
T4
GND2
DI DO
OOT5
(Passive Distribution
Network)
(Immunity Behavior)
T5
ICIM-CI model(Integrated Circuit Immunity Model
for Conducted Immunity)
IEC 62433-4
・Linear: PDN(Passive Distribution Network)
・Frequency-domain simulation
Conventional NewFor CW disturbance For Pulse disturbance
(Non Linear Block)
FB
PPN
VDD1 VDD2
GND1 GND2
T1
T2
T3
[S]Disturbance
Background - Immunity macro model (ICIM-CPI model)
Description of ICIM-CPI model
ICIM-CPI model(Integrated Circuit for Immunity behavioral simulation – Conducted Pulse Immunity)
PDN (Passive Distribution Network)…Linear transmission
NLB(Non Linear Block)…Nonlinear behavior (Voltage dependency)
6
Future IEC 62433-6
PDN Block
― passive elementsEx)package inductance
stray capacitance
NLB Block
― ESD protections
Ex)diodes, MOSFET
FB
PPN
VDD1 VDD2
GND1 GND2
T1
T2
T3
[S]Disturbance
Background - Immunity macro model (ICIM-CPI model)
Description of ICIM-CPI model
ICIM-CPI model(Integrated Circuit for Immunity behavioral simulation – Conducted Pulse Immunity)
7
Future IEC 62433-6
10 50 100 500 10000.1
0.51
510
50100
500
Frequency [MHz]
|Z |
[
Z11
Z22
PDN block
NLB: I-V Curve
ie) Measurement, TLP
PDN: S-parameters
FB
PPN
VDD1 VDD2
GND1 GND2
T1
T2
T3
[S]Disturbance
11 12 130
0.01
0.02 SPICE model Approximation method
VD [V]
I D [
A]
NLB block
Our proposal and approach
Equivalent circuit model
ICIM-CPI model(Integrated Circuit for Immunity behavioral simulation – Conducted Pulse Immunity)
8
Future IEC 62433-6
How to extract and represent the
NLB behavior?
Equivalent Circuit Model
1. Extract nonlinear characteristics by measurement
2. Use an appropriate function and approximate the characteristic
Equivalent Circuit
ExpressionI (V)C(V)
Voltage-dependence
9
Our proposal and approach
Equivalent Circuit Model
Target: Zener diode (simple case)
𝑅𝐷𝐶𝐷
: Nonlinear resistor
: Nonlinear junction capacitance
Extract characteristics
(by measurement or SPICE)
…PDN
…NLB
Equivalent CircuitExpression
L
RD CDDV
ID
L
DV
ID
* DPTZ12B D model* PKG: PMDS,Vz=12V at
Iz=20mA,Pd=1W* Model Generated by ROHM
* All Rights Reserved* Commercial Use or* Resale Restricted* Date: 2015/09/16.MODEL DPTZ12B D
+ IS=6.1497E-15
𝐼𝐷 =
𝑛
exp(𝑎𝑛𝑉𝐷𝑛)
Extract data by DC characteristic
𝑅𝐷 :Voltage-controlled current source
Function
Approximate
using least squares method
Our proposal and approach
Represent Nonlinearity (I-V characteristic)
D
D
RD
CD
11 12 130
0.01
0.02 SPICE model
VD [V]
I D [
A]
11 12 130
0.01
0.02 SPICE model Approximation method
VD [V]
I D [
A]
I-V characteristic
10
D
Vector
Network
Analyzer
DC Feed
DC Block
Measured by Vector Network Analyzer
Get Z-parameters (Voltage dependency)
Find C from the inclination of line
:Voltage-controlled capacitor𝐶𝐷
RD
CD
Approximate
using least squares method
Compare
Our proposal and approach
Represent Nonlinearity(C-V characteristic)
Continue…
11
0V
5V
10V
Find C from the inclination of line
Approximate
using least squares method
Our proposal and approach
Represent Nonlinearity(C-V characteristic)
𝐶𝐷 = 𝛼0 0.5 + 𝑉𝐷−1𝑁
Function
RD
CD
0 5 10
200
300
400
CD
[pF
]
VD [V]
SPICE model Approximation curve
0 5 10
200
300
400
CD
[pF
]
VD [V]
SPICE model
:Voltage-controlled capacitor𝐶𝐷
12
105 106 107 108 10910-2
10-1
100
101
102
103
0V 5V 10V
|Im
{Z
}|
f[Hz]
0V
5V
10V
Simulation
ESD test simulation
RD
CD
ESD gun
Validate the model by comparing responses to ESD
Does ESD
responses
match?
For ESD test simulation … Using characteristics extracted from SPICE model
For actual measurement ... Using ESD gun and
characteristics extracted from measurement
Used Device is
PTZ12B (ROHM)
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RD
CD
ESD gun
Simulation
ESD test simulation
Level
1
2
3
4
V[kV]
2
4
6
8
Peak[A]
7.5
15
22.5
30
t [ns]r
0.7 – 1.0
0.7 – 1.0
0.7 – 1.0
0.7 – 1.0
I (30ns)[A]
4
8
12
16
I (60ns)[A]
2
4
6
8
IEC61000-4-2 test standard
Circuit for ESD current generation
Does ESD
responses
match?
14
214 348
75 nH 2.4 uH
7 pF 143 pF
Simulation
Characteristics of the proposed model
𝑅𝐷 :Voltage-controlled current source
𝐼𝐷 =
𝑛
exp(𝑎𝑛𝑉𝐷𝑛) 𝐶𝐷 = 𝛼0 0.5 + 𝑉𝐷
−1𝑁
Value Value
a
a
a
a
a
a
a
a
0
1
2
3
4
5
6
7 5.71E-04
-2.43E-02
4.07E-01
-3.39-3.20E01
2.77E01
-3.15E01
1.48E01
𝐶𝐷 = 281.6 × 0.5 + 𝑉𝐷−13
Approximate
Next : Results
RD
CD
:Voltage-controlled capacitor𝐶𝐷
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Simulation
Results / Discussion
0 20 40 60 80 1000
10
20
Time [ns]
I [A
]
0 20 40 60 80 1000
10
20 SPICE model Proposed model
Time [ns]
I [A
]
0 2 4 6 8 10
0
100
200
300
400
500
Time [ns]
V [
V]
SPICE model Proposed model
Input current
The results from the proposed models were in good agreement
with the results from SPICE model
IEC61000-4-2 test standard
Level V[kV] Peak[A] t [ns]r I (30ns)[A] I (60ns)[A]
3 6 22.5 0.7 – 1.0 12 6
𝐼𝐷 𝑉𝐷
MATCH MATCH
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D
D
ESD gun
RD
CD
When C was linear…
Different
When the capacitor is set to a linear value,
the model CANNOT express ESD response correctly.
0 5 10
200
300
400
CD
[pF
]
VD [V]
0 5 10
200
300
400
CD
[pF
]
VD [V]
CD = 200pF
CD = 150pF
The evidence supporting the importance of voltage dependency
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Simulation
Results / Discussion
0 5 10 150
5
10
15
Time[ns]
V [
V]
SPICE model Proposed model Linear C: 150pF Linear C: 200pF
Conclusion
Demand: Predicting the immunity behavior to ESD
Proposal: Equivalent circuit model using function approximation
𝐶𝐷 = 𝛼0 0.5 + 𝑉𝐷−1𝑁
𝐼𝐷 =
𝑛
exp(𝑎𝑛𝑉𝐷𝑛)
0 2 4 6 8 10
0
100
200
300
400
500
Time [ns]
V [
V]
SPICE model Proposed model
0 5 10 150
5
10
15
Time[ns]
V [
V]
SPICE model Linear C: 150pF Linear C: 200pF
Results: The ESD test results simulated using the proposed model
correlate well with the results using SPICE model
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