CoolSPICE: Circuit and Device Design

Tool for WBG Power Device Applications

Akin Akturk, Neil Goldsman,

Andrew Kim, James McGarrity, Zeynep Dilli, Mitch Gross

Supported by ARL, PowerAmerica, NASA

Thank you

Unique Attributes of CoolSPICE

Standard Capabilities

• Electrical Circuit Simulator (A User Friendly Version of SPICE)

• Calculates Branch Currents and Node Voltages in Advanced Circuits

Unique Capabilities (Not Available in Standard SPICE)

• Thermal Circuit Simulator

– Calculates temperature at every thermal node

• Electrical – Thermal Co-Simulation

– Consistently calculates circuit heating

due to power loss and its effect on electrical

performance.

• New Wide Bandgap Devices

– Has unique transistor and related device

models so it can simulate circuits composed

of non-standard and new devices, including SiC and GaN

• Both Detailed Distributed and Fast Lumped Thermal Simulation

• Can simulate cryogenic and radiation effects for CMOS devices.

CoolSPICE-WBG LT Spice

SiC Models Y Y (Behavioral)

Simulation Environment Y Y

Thermal Modeling Y N

Circuit Design Y Y

Co-Design Electrical and Thermal Y N

CoolSPICE: Modules

Unique CoolSPICE capabilities are implemented into Modules

User can Mix and Match Modules, Libraries and Models.

• CoolSPICE Student: Standard Capabilities

• CoolSPICE Power

• CoolSPICE TCAD

• CoolSPICE Thermal

• CoolSPICE Cryogenic

• PSIM-CoolSPICE Add-on

3

Silicon Carbide Device, Module,

System Simulations

CoolSPICE Electrical

and Thermal Circuit

Simulator

SiC Power Module and

System DesignStudent version is available online

http://coolcadelectronics.com/coolspice/

0 5 10 15 20 250

5

10

15

Dra

in C

urr

ent (A

)

0 5 10 15 20 250

100

200

300

Time (us)

Dra

in V

oltage (

V)

Distributed:

Use Euler’s Conservation

Equations

• System of coupled partial

differential equations

• 3 dimensions in space

• Use computational fluid

mech. FEM/FDM tools

• Excellent for detailed

analysis of simple systems

Lumped Elements:

Use Thermal Resistors and Capacitors.

• Analogous to circuit analysis

for Electrical Systems.

• Calculate thermal resistors

and capacitors for elements.

• Arrange in circuit loops.

• Input to thermal Spice, solve

for node temperatures

• Excellent for fast analysis of

large system

Methods of Thermal Analysis

Rth2

Value=1

Rth3

Value=1

Cth2Value=1n

HS1

Enable=Y

Hdc=0

Hac=Rth1

Value=1

Cth1

Value=1n

GND

Tmeter1Tmeter2

Tmeter3

Method for Distributed Analysis

+ doping unif p.type conc=3e17 x.l=-5.5 x.h=0.7 y.l=0.0 y.h=2.0

+ doping unif n.type conc=5e15 x.l=-5.5 x.h=10.5 y.l=3.0 y.h=12.0

+ doping unif n.type conc=5e16 x.l=-5.5 x.h=10.5 y.l=0.0 y.h=3.0

+ doping unif n.type conc=1e18 x.l=-5.5 x.h=10.5 y.l=11.0 y.h=12.0

+ doping exp lat.rotate n.type conc=1e20 x.l=-5.5 x.h=0.0 y.l=0

y.h=0.2 ratio=1 char.len=0.022

+

+ models concmob fieldmob bgn srh conctau surfmob

CoolSPICE for Power: CoolSPICE/PSIM

Pros:

1. Wide Bandgap Device Models: SiC / GaN:

Inherently more stable than behavioral models

2. Integrated with PSIM

Widely used power system design tool

WBG version with generic models is planned to be launched soon

3. Has Thermal Capability Integrated In

Enables co-thermal and electrical simulation

4. Ease of switch from LTSPICE format

Minimizes effort to switch

Cons:

1. LTSPICE is the white elephant in the room. It is widely used and has

a unique ability to convergence in many cases

A Synergistic Pair: PSIM-CoolSPICE Module

User Friendly Power Device Model Entry

- Enter current and voltage rating

- Enter Rg, Rd

- Using simple guidelines, slightly change few

device parameters to obtain fits to measured

DC characteristics

User Friendly Capacitance Model Entry

0

100

200

300

400

500

600

700

-1 1 3 5 7 9 11

Cap

acit

an

ce (

F)

Voltage (V)

Adjusted

Datasheet

cscale‘log’ or ‘line’ to set the capacitance

(y-axis) scale

vscale‘log’ or ‘line’ to set the voltage

(x-axis) scale

ciscale scalar to normalize Ciss values

coscale scalar to normalize Coss values

crscale scalar to normalize Crss values

cix1 ... cix10, ciy1 ... ciy10(x,y) coordinate pairs of selected Ciss

data points

cox1 ... cox10, coy1 ... coy10(x,y) coordinate pairs of selected Coss

data points

crx1 ... crx10, cry1 ... cry10(x,y) coordinate pairs of selected Crss

data points

Alternating line and

arc interpolation for a

continuous CV curve

with a continuous

derivative- Enter CISS, CRSS

and COSS values

as seen in the

datasheet

- Perform

interpolation,

rounding and

extrapolation

- Determine device

terminal caps

Double Pulse Test Simulation for

Eon –Eoff Calculations

SCT2280KE Sim Datasheet

Eon 45µJ 57 µJ

Eoff 22 µJ 20 µJ

C3M0065090J Before Datasheet

Eon 38 µJ 39 µJ

Eoff 17 µJ 17 µJ

Double Pulse Test Simulation in

PSIM for Eon –Eoff Calculations

Summary

- We will have a CoolSPICE table at ICSCRM. Please visit to test drive the

simulator and the new models.

- The standalone CoolSPICE and the PSIM CoolSPICE add-on can efficiently

simulate WBG devices with physics based details incorporated into the

model.

- The CoolSPICE engine can be used to couple distributed power device

models with those of standard SPICE elements to determine the effect of

process / design changes on fundamental circuits

- The electrical – thermal coupling can be achieved for more realistic circuit

and efficiency calculations.

Email: akin.akturk@coolcadelectronics.com