Mini DIP (SPM3) Application Note (2012-07-09)
Application Note AN-9044
Smart Power Module
Motion SPM® in Mini DIP (SPM3 V4)
User’s Guide
Written by:
Application Engineering Part
Motion Control System Team
HV PCIA
Fairchild Semiconductor
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Mini DIP (SPM3) Application Note (2012-07-09)
Contents
1.
Introduction ............................................................................................ 4
1.1 Introduction.......................................................................................................................................... 4
1.2 Mini DIP SPM Design Concept ............................................................................................................ 4
1.3 Mini DIP SPM Technology ................................................................................................................... 5
1.4 Advantage of Mini DIP SPM-driven inverter drives ........................................................................... 7
1.5 Summary .............................................................................................................................................. 9
2.
Mini DIP SPM Product Outline ............................................................ 10
2.1 Ordering Information ......................................................................................................................... 10
2.2 Product Line-Up ................................................................................................................................. 10
2.3 Applications ....................................................................................................................................... 10
2.4 Package Structure .............................................................................................................................. 11
3.
Outline and Pin Description ................................................................ 12
3.1 Outline Drawings ............................................................................................................................... 12
3.2 Description of the input and output pins ......................................................................................... 16
3.3 Description of dummy pins............................................................................................................... 19
4.
Internal Circuit and Features .............................................................. 20
5.
Absolute Maximum Ratings ................................................................ 22
5.1 Electrical Maximum Ratings ............................................................................................................. 22
6.
Interface Circuit .................................................................................... 24
6.1 Input/Output Signal Connection ....................................................................................................... 24
6.2 General Interface Circuit Example.................................................................................................... 26
6.3 Recommended Wiring of Shunt Resistor and Snubber Capacitor ................................................ 28
7.
Function and Protection Circuit ......................................................... 29
7.1 SPM Functions versus Control Power Supply Voltage................................................................... 29
7.2 Under-Voltage Protection .................................................................................................................. 30
7.3 Short-Circuit Protection .................................................................................................................... 32
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7.3.1 Timing chart of Short Circuit (SC) Protection ........................................................................... 32
7.3.2 Selecting Current Sensing Shunt Resistor ................................................................................ 33
7.4 Fault Output Circuit ........................................................................................................................... 36
7.5 TSD (Thermal Shut-Down) Protection .............................................................................................. 37
8.
Bootstrap Circuit .................................................................................. 37
8.1 Operation of Bootstrap Circuit ......................................................................................................... 37
8.2 Initial Charging of Bootstrap Capacitor ........................................................................................... 38
8.3 Selection of a Bootstrap Capacitor .................................................................................................. 38
8.4 Built in Bootstrap Diode including around 15 Resistance characteristics ................................. 39
8.5 Charging and Discharging of the Bootstrap Capacitor during PWM-Inverter Operation ............. 40
8.6 Recommended Boot Strap Operation Circuit and Parameters ...................................................... 41
9.
Power Loss and Dissipation ............................................................... 42
9.1 Power Loss of SPM ........................................................................................................................... 42
9.1.1 Conduction Loss ......................................................................................................................... 42
9.1.2 Switching Loss ............................................................................................................................ 43
9.2 Thermal Impedance ........................................................................................................................... 44
9.2.1 Overview ...................................................................................................................................... 44
9.2.2 Measurement Method .................................................................................................................. 47
9.2.3 Measurement Procedures ........................................................................................................... 48
9.3 Temperature Rise Considerations and Calculation Example......................................................... 51
9.4 Heat Sink Design Guide .................................................................................................................... 52
10. Package ................................................................................................ 56
10.1 Heat Sink Mounting ......................................................................................................................... 56
10.2 Handling Precaution ........................................................................................................................ 57
10.3 Marking Specifications .................................................................................................................... 59
10.4 Packaging Specifications................................................................................................................ 61
NOTE:
In this and other Fairchild documentation and collateral, the following terms are interchangeable:
DIP = SPM2, Mini-DIP = SPM3, Tiny-DIP = SPM5, and µMini-DIP = SPM45H.
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1. Introduction
1.1 Introduction
The terms “energy-saving” and “quiet-running” are becoming very important in the world of variable
speed motor drives. For low-power motor control, there are increasing demands for compactness, built-in
control, and lower overall-cost. An important consideration, in justifying the use of inverters in these
applications, is to optimize the total-cost-performance ratio of the overall drive system. In other words, the
systems have to be less noisy, more efficient, smaller and lighter, more advanced in function and more
accurate in control with a very low cost.
In order to meet these needs, Fairchild has developed a new series of compact, high-functionality, and
high efficiency power semiconductor device called “Mini DIP SPM (Mini DIP Smart Power Module)”. Mini
DIP SPM-based inverters are now considered an attractive alternative to conventional discrete-based
inverters for low-power motor drives, specifically for appliances such as washing machines, air-conditioners,
refrigerators, water pumps etc.
Mini DIP SPM combines optimized circuit protection and drive matched to the IGBT’s switching
characteristics. System reliability is further enhanced by the integrated under-voltage protection function and
short circuit protection function. The high speed built-in HVIC provides an opto-coupler-less IGBT gate
driving capability that further reduces the overall size of the inverter system design. Additionally, the
incorporated HVIC allows the use of a single-supply drive topology without negative bias.
The objective of this application note is to show the details of Mini DIP SPM power circuit design and
its application to Mini DIP SPM users. This document provides design examples that should enable motor
drive design engineers to create efficient optimized designs with shortened design cycles by employing
Fairchild Mini DIP SPM products.
1.2 Mini DIP SPM Design Concept
The key Mini DIP SPM design objective is to create a smart power module with improved reliability.
This is achieved by applying existing IC and LSI transfer mold packaging technology. The Mini DIP SPM
structure is relatively compact: power chips and IC chips are directly die bonded on the copper lead frame,
the bare ceramic material is attached to the frame, and then molded into epoxy resin. In comparison, the
conventional IPM is made of power chips bonded on a metal or ceramic substrate with the ICs and the
passive components assembled on a PCB. This is then assembled into a plastic or epoxy resin case and
filled up with silicon gel. The Mini DIP SPM greatly minimizes the number of parts and material types,
optimizing the assembly process and overall cost.
A second important Mini DIP SPM design advantage is the realization of a product with smaller size
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and higher power rating. Of the low power modules released to date, the Mini DIP SPM has the highest
power density with 3A to 30A rated products built into a single package outline.
The third design advantage is design flexibility enabling use in a wide range of applications. The Mini
DIP SPM series has the 3-N terminal structure with the negative rail IGBT emitters terminated separately.
With this structure, shunt resistance can be placed in series with each 3-N terminal to easily sense individual
inverter phase currents.
The detailed features and integrated functions of Mini DIP SPM are as follows:
600V/3A to 30A ratings in one package (with identical mechanical layouts)
Low-loss efficient IGBTs and FRDs optimized for motor drive applications
High reliability due to fully tested coordination of HVIC and IGBTs
3-phase IGBT Inverter Bridge including control ICs for gate drive and protection
— High-Side Features: Control circuit under voltage (UV) protection (without fault signal output)
— Low-Side Features: UV, Thermal Shut Down(TSD) and short-circuit (SC) protection
through external shunt resistor (With fault signal output),
Single-grounded power supply and opto-coupler-less interface due to built-in HVIC
Active-High input signal logic resolves the startup and shutdown sequence constraint between the
VCC control supply and control input providing fail-safe operation with direct connection between the
Mini DIP SPM and a 3.3V CPU or DSP. Additional external sequence logic is not needed
Divided negative DC-link terminals for inverter applications requiring individual phase current
sensing
Easy PCB layout due to built in bootstrap diode
Isolation voltage rating of 2500Vrms for one minute
Very low leakage current due to full molded or DBC substrate.
1.3 Mini DIP SPM Technology
POWER Devices – IGBT and FRD
The Mini DIP SPM performance improvement is primarily the result of the technological advancement
of the power devices (i.e., IGBTs and FRDs) in the 3-phase inverter circuit.
The fundamental design goal is
to reduce the die size and increase the current density of these power devices. The Mini DIP SPM IGBTs
represent Fairchild's latest technology.
Through optimized NPT IGBT design, they maintain an SOA (Safe
Operating Area) suitable for motor control application while dramatically reducing the on-state conduction
and turn-off switching losses. They also implement smooth switching performance without sacrificing other
characteristics. The FRDs are Ultrafast diodes that have a low forward voltage drop along with soft recovery
characteristics.
Control IC – LVIC, HVIC & Bootstrap diode
The Mini DIP SPM HVIC and LVIC driver ICs were designed to have only the minimum necessary
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functionality required for low power inverter drives. The HVIC has a built-in high voltage level shift function
that enables the ground referenced PWM signal to be sent directly to the Mini DIP SPM’s assigned high side
IGBT gate circuit. This level shift function enables opto-coupler-less interface, making it possible to design a
very simple system. In addition a built-in under-voltage lockout (UVLO) protection function interrupts IGBT
operation under control supply under-voltage conditions. Because the bootstrap charge-pump circuit
interconnects to the low-side VCC bias internal to the Mini DIP SPM, the high-side gate drive power can be
obtained from a single 15V control supply referenced to control ground. It is not necessary to have three
isolated voltage sources for the high-side IGBT gate drive required in inverter systems that use conventional
power modules. Mini DIP SPM V4 incorporates built in bootstrap diodes which characteristics are fast
reverse recovery including bootstrap resistance characteristics, about 15 ohm.
Recent progress in the HVIC technology includes chip downsizing through the introduction of wafer
fine process technology.
Input control logic change from the conventional low active to high active permits
direct interface to 3.3V micro-controllers or DSPs. This provides low circuit current, increased noise immunity
and good performance stability against temperature variation.
Package Technology
Since heat dissipation is an important factor limiting the power module’s current capability, the heat
dissipation characteristics of a package are critical in determining the Mini DIP SPM performance.
A trade-
off exists between heat dissipation characteristics and isolation characteristics. The key to a good package
technology lies in the implementation of outstanding heat dissipation characteristics without compromising
the isolation rating.
In Mini DIP SPM, a technology was developed in which bare ceramic with good heat dissipation
characteristics is attached directly to the lead frame. For expansion to a targeted power rating of 20A and
30A in this same physical package size, DBC (Direct Bonding Copper) technology was applied. In addition,
for optimization of cost to performance up to a power rating of 10A, full molded type technology was applied.
This made it possible to achieve optimum trade-off characteristics while maintaining cost-effectiveness.
Figure 1.1 shows the cross sections of the Mini DIP SPM V4 package. In full molded packages, the
lead frame structure was bent to secure the required electrical spacing. In DBC package, the lead frame and
the DBC substrate are directly soldered into the Mini DIP SPM lead frame.
Inverter System Technology
The Mini DIP SPM package is designed to satisfy the basic UL, IEC and etc. clearance and creepage
spacing safety regulations required in inverter systems. In Mini DIP SPM, 3.1mm clearance and 4mm
creepage were secured in all areas where high voltage is applied. Exceptionally, 2.65mm clearance and
3.7mm creepage were secured in full molded type package. In addition, the Cu frame pattern and wire
connection have been optimized with the aid of computer simulation for less parasitic inductance, which is
favorable to the suppression of voltage surge at high frequency switching operation.
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IC
Al
Wire IGBT
Lead
Frame
DBC
FRD
Epoxy Molding Compound
Full pack
Figure 1.1 Cross Sections of Mini DIP SPM
HVIC is sensitive to noise since it is not a complete galvanic isolation structure but is implemented as a
level shift latch logic using high voltage LDMOS that passes signals from upper side gate and lower side
gate. Consequently, it was designed with sufficient immunity against such possible malfunctions as latch-on,
latch-up, and latch-off caused by IGBT switching noise and system outside noise. Fairchild’s Mini DIP SPM
design has also taken into consideration the possibility of high side malfunction caused by short PWM pulse.
Since the low voltage part and the high voltage part are configured onto the same silicon in the HVIC, it
cannot operate normally when the electric potential in the high voltage part becomes lower than the ground
of the low voltage part. Accordingly, sufficient margin was given to take into consideration the negative
voltage level that could cause such abnormal operation. Soft turn-off function was added to secure basic
IGBT SOA (Safe Operating Area) under short circuit conditions.
1.4 Advantage of Mini DIP SPM-driven inverter drives
SPM Inverter Engine Platform
Mini DIP SPM was designed to have 3A~30A rated current of products built into a single package
outline. Figure 1.2 shows the junction to case thermal resistance at each current range of the Mini DIP SPM.
As seen in the figure, in the 15A, 20A and 30A range, intelligent 3-phase IGBT module with high power
density (Size vs. Power) was implemented. Accordingly, in the low power range, inverter system designers
are able to cover almost the entire range of 0.1KW~3KW rating in a single power circuit design using Mini
DIP SPM. Since circuitry and tools can become more standardized, product development and testing
process are simplified, significantly reducing development time and cost. Through control board
standardization, overall manufacturing cost will be substantially reduced as users are able to simplify
materials purchasing and maintain manufacturing consistency.
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Figure 1.2 Junction-to-case Thermal Resistance according to Current Rating of Mini DIP SPM Line-up
Noise Reduction
Small package and low power loss are the primary goals of low power modules. However, in recent
years, attempting to reduce power loss through excessively fast switching speed has given rise to various
challenges.
Excessive switching speed increases the dV/dt, di/dt, and recovery current and creates
challenges such as large EMI (Electromagnetic Interference), excessive surge voltage, and high magnitude
of motor leakage current. Such problems increase system cost and can even shorten motor life. Mini DIP
SPM series solve these problems by adjusting the switching dV/dt to around 3kV/sec through advanced
gate drive impedance design.
Thanks to very low on-state voltage of the new generation IGBT and low forward voltage of FRD, an
optimized switching speed meeting the low EMI requirement has been realized in Mini DIP SPM while
keeping the total power loss at a low level equal to or less than other low power modules.
Cost-effective Current Detection
As sensor-less vector control and other increasingly sophisticated control methods are applied to
general industrial inverters and even in consumer appliance inverters, there is a growing need to measure
inverter phase current. Mini DIP SPM family has a 3-N terminal structure in which IGBT inverter bridge
emitter terminal is separated. In this type of structure, inverter phase current can be easily detected simply
by using external shunt resistance.
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1.5 Summary
From 1999, when the SPM series was first developed, to the present, Fairchild has manufactured
millions of 600V SPM series in the power range of 300W~2.2kW for consumer appliances and low power
general industry applications. Today, the SPM has positioned itself as a strong inverter solution for low
power motor control.
With its compact size, optimized performance, high reliability, and low cost, the SPM
family is accelerating the inverterization not only of low power industrial applications but also of consumer
appliances. Fairchild will continue its effort to develop the next generation of SPMs optimized for a broader
variety of applications and with higher power rating in mind.
For more information on Fairchild’s SPM products, please visit
http://www.fairchildsemi.com/spm
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2. Mini DIP SPM Product Outline
2.1 Ordering Information
FSBF10CH60B
None : V2 Mini DIP SPM
B
: V4 Mini DIP SPM
( Full Molded Type)
C
: V4 Mini DIP SPM
( DBC Type)
Voltage Rating ( x 10)
CH : Option for Motor Drives
Current Rating
B : DBC Base
F : Full Molded Type
B : Option for No-Thermistor
S : Divided Three Terminal
Fairchild Semiconductor
2.2 Product Line-Up
Table 2.1 Lineup of Mini DIP SPM Family
Rating
Isolation
Part Number
Package
Current (A)
Voltage (V)
30
600
Main Applications
Voltage(Vrms)
DBC substrate
FSBB30CH60C
(SPM27-EC)
Air Conditioner
FSBB20CH60C
20
FSBB20CH60CT
20
FSBB15CH60C
15
FSBB15CH60BT
15
FSBF15CH60BT
15
FSBF10CH60B
10
2500Vrms
Washing Machine
DBC substrate
Sinusoidal, 1min
Industrial Inverter
600
FSBF10CH60BT
10
FSBF5CH60B
5
FSBF3CH60B
3
(SPM27-CC)
Air Conditioner
Full Molded
2500 Vrms
(SPM27-JA)
Sinusoidal, 1min
600
Washing Machine
Refrigerator
2.3 Applications
Motor drive for household electric appliances, such as air conditioners, washing machines, refrigerators, dish
washers, and low power industrial applications as well.
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2.4 Package Structure
Figure 2.1 contains a picture and an internal structure illustration of the Mini DIP SPM. The Mini DIP SPM is an
ultra-compact power module, which integrates power components, high and low side gate drivers and protection circuitry
for AC100 ~ 220V class low power motor drive inverter control into a dual-in-line transfer mold package.
Top View
44mm
Mold Resin
26.8m
FRD
5.5
Bottom View
2.65
IGBT
LVIC, HVIC
( unit : mm )
(a) SPM27-JA
Top View
44mm
Copper
Ceramic
26.8m
Mold Resin
Bottom View
3.1
( unit : mm )
FRD
IGBT
LVIC, HVIC
(b) SPM27-CC, SPM27-EC
Figure 2.2 Pictures and Package Cross section
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3. Package and Pin Description
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
3.1 Outline Drawings
1
2
3
4
5
6
7
8
9
10
11
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VCC(L)
COM
IN(UL)
IN(VL)
IN(WL)
VFO
CFOD
CSC
IN(UH)
VCC(UH)
VB(U)
Pin Arrangement
12 VS(U)
23
13 IN(VH)
24
14 VCC(VH)
25
15 VB(V)
26
16 VS(V)
27
17 IN(WH)
18 VCC(WH)
19 VB(W)
20 VS(W)
21 NU
22 NV
NW
U
V
W
P
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(a) SPM27-JA
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Pin Arrangement
1
VCC(L)
12
VS(U)
23
NW
2
COM
13
IN(VH)
24
U
3
IN(UL)
14
VCC(VH)
25
V
4
IN(VL)
15
VB(V)
26
W
5
IN(WL)
16
VS(V)
27
P
6
VFO
17
IN(WH)
7
CFOD
18
VCC(WH)
8
CSC
19
VB(W)
9
IN(UH)
20
VS(W)
10
VCC(UH)
21
NU
22
NV
11 VB(U)
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(b) SPM27-CC, SPM27-EC
Figure 3.1 Package Outline Dimensions
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Mini DIP (SPM3) Application Note (2012-07-09)
3.2 Description of the input and output pins
Table 3.1 defines the Mini DIP SPM input and output pins. The detailed functional descriptions are as
follows:
Table 3.1 Pin descriptions
Pin Number
Pin Name
1
VCC(L)
Low-side Common Bias Voltage for IC and IGBTs Driving
2
COM
Low-Side Common Supply Ground
3
IN(UL)
Signal Input for Low-Side U Phase
4
IN(VL)
Signal Input for Low-Side V Phase
5
IN(WL)
Signal Input for Low-Side W Phase
6
VFO
Fault Output
7
CFOD
Capacitor for Fault-output Duration Time Selection
8
CSC
Capacitor (Low-pass Filter) for Short-Current Detection Input
9
IN(UH)
10
VCC(UH)
11
VB(U)
High-Side Bias Voltage for U Phase IGBT Driving
12
VS(U)
High-Side Bias Voltage Ground for U Phase IGBT Driving
13
IN(VH)
Signal Input for High-side V phase
14
VCC(VH)
15
VB(V)
High-Side Bias Voltage for V Phase IGBT Driving
16
VS(V)
High-Side Bias Voltage Ground for V Phase IGBT Driving
17
IN(WH)
Signal Input for High-side W phase
18
VCC(WH)
19
VB(W)
High-Side Bias Voltage for W Phase IGBT Driving
20
VS(W)
High-Side Bias Voltage Ground for W Phase IGBT Driving
21
NU
Negative DC-Link Input for U Phase
22
NV
Negative DC-Link Input for V Phase
23
NW
Negative DC-Link Input for W Phase
24
U
Output for U Phase
25
V
Output for V Phase
26
W
Output for W Phase
27
P
Positive DC-Link Input
© 2008
Pin Description
Signal Input for High-side U phase
High-Side Bias Voltage for U Phase IC
High-Side Bias Voltage for V Phase IC
High-Side Bias Voltage for W Phase IC
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High-Side Bias Voltage Pins for Driving the IGBT / High-Side Biase Voltage Ground Pins for
Driving the IGBT
Pins : VB(U) – VS(U) , VB(V) – VS(V) , VB(W) – VS(W)
These are drive power supply pins for providing gate drive power to the High-Side IGBTs.
The virtue of the ability to boot-strap the circuit scheme is that no external power supplies are
required for the high-side IGBTs
Each boot-strap capacitor is charged from the Vcc supply during the ON-state of the
corresponding low-side IGBT.
In order to prevent malfunctions caused by noise and ripple in supply voltage, a good quality (low
ESR, low ESL) filter capacitor should be mounted very close to these pins
Low-Side Bias Voltage Pin / High-Side Bias Voltage Pins
Pin : VCC(L), VCC(UH), VCC(VH), VCC(WH)
These are control supply pins for the built-in ICs.
These four pins should be connected externally.
In order to prevent malfunctions caused by noise and ripple in the supply voltage, a good quality
(low ESR, low ESL) filter capacitor should be mounted very close to these pins.
Low-Side Common Supply Ground Pin
Pin : COM
The Mini DIP SPM common pin connects to the control ground for the internal ICs.
Important! To avoid noise influences the main power circuit current should not be allowed to blow
through this pin.
Signal Input Pins
Pin : IN(UL), IN(VL), IN(WL), IN(UH), IN(VH), IN(WH)
These are pins to control the operation of the built-in IGBTs .
They are activated by voltage input signals. The terminals are internally connected to a schmitt
trigger circuit composed of 5V-class CMOS.
The signal logic of these pins is Active-high.
That is the IGBT associated with each of these
pins will be turned "ON" when a sufficient logic voltage is applied to these pins.
The wiring of each input should be as short as possible to protect the Mini DIP SPM against
noise influences.
To prevent signal oscillations, an RC coupling is recommended as illustrated in Fig. 6.1.
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Mini DIP (SPM3) Application Note (2012-07-09)
Short-Current Detection Pins
Pin : CSC
The current sensing shunt resistor should be connected between the pin CSC and the low-side
ground COM to detect short-current (reference Fig. 7.4)
The shunt resistor should be selected to meet the detection levels matched for the specific
application. An RC filter should be connected to the pin CSC to eliminate noise.
The connection length between the shunt resistor and CSC pin should be minimized.
Fault Output Pin
Pin : FO
This is the fault output alarm pin. An active low output is given on this pin for a fault state
condition in the SPM. The alarmed conditions are SC (Short Circuit) or low-side bias UV (Under
Voltage) operation.
The VFO output is of open collector configured. The FO signal line should be pulled up to the 5V
logic power supply with approximately 4.7k resistance.
Fault Out Duration Time Selection Pin
Pin : CFOD
This is the pin for selecting the fault out pulse length.
An external capacitor should be connected between this pin and COM to set the fault out pulse
length.
The fault-out pulse width tFOD depends on the capacitance value of CFOD according to the
following approximate equation : CFOD
= 18.3 x 10-6 x TFOD [F]. (18.3 is internal setting value of
LVIC)
Positive DC-Link Pin
Pin : P
This is the DC-link positive power supply pin of the inverter.
It is internally connected to the collectors of the high-side IGBTs.
In order to suppress the surge voltage caused by the DC-link wiring or PCB pattern inductance,
connect a smoothing filter capacitor close to this pin. (Typically Metallized Film Capacitors are
used)
Negative DC-Link Pins
Pin : NU, NV, NW
These are the DC-link negative power supply pins (power ground) of the inverter.
These pins are connected to the low-side IGBT emitters of the each phase.
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Mini DIP (SPM3) Application Note (2012-07-09)
Inverter Power Output Pin
Pin : U, V, W
Inverter output pins for connecting to the inverter load (e. g. motor).
3.3 Description of dummy pins
Figure 3.2 defines the Mini DIP SPM dummy pins.
Figure. 3.2 Description of dummy pins
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Mini DIP (SPM3) Application Note (2012-07-09)
4. Internal Circuit and Features
Figure 4.1 illustrates the internal block diagram of the Mini DIP SPM. It should be noted that the Mini
DIP SPM consists of a three-phase IGBT inverter circuit power block and four drive ICs for control functions.
The detailed features and integrated functions of Mini DIP SPM and the benefits acquired by using it are
described as follows.
(19) VB(W)
(18) VCC(H)
(17) IN(WH)
(20) VS(W)
(15) VB(V)
(14) VCC(H)
(13) IN(VH)
(16) VS(V)
(11) VB(U)
(10) VCC(H)
(9) IN(UH)
(12) VS(U)
(8) CSC
(7) CFOD
(6) VFO
(5) IN(WL)
(4) IN(VL)
(3) IN(UL)
P (27)
VB
VCC
COM
IN
OUT
VS
W (26)
VB
VCC
COM
IN
OUT
VS
V (25)
VB
VCC
COM
IN
OUT
VS
U (24)
C(SC) OUT(WL)
C(FOD)
NW (23)
VFO
IN(WL) OUT(VL)
IN(VL)
NV (22)
IN(UL)
(2) COM
COM
(1) VCC(L)
VCC
OUT(UL)
VSL
NU (21)
Figure 4.1 Internal circuit
Features
600V/3A to 30A rating in one physical package size (mechanical layouts are identical)
Low-loss efficient IGBTs and FRDs optimized for motor drive applications
Compact and low-cost transfer mold package allows inverter design miniaturization.
High reliability due to fully tested coordination of HVIC and IGBTs.
3-phase IGBT Inverter Bridge including control ICs for gate driving and protection
-
High-side: Control circuit under voltage (UV) protection (without fault signal output)
-
Low-side: UV, Thermal Shut Down (TSD) and Short-Circuit (SC) protection by means of
external shunt resistor. (with fault signal output)
Single-grounded power supply and opto-coupler-less interface due to built-in HVIC
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Mini DIP (SPM3) Application Note (2012-07-09)
IGBT switching characteristics matched to system requirement.
Low leakage current and high isolation voltage due to DBC-based substrate
Divided 3-N Power Terminals provide easy and cost-effective phase current sensing.
Easy to PCB layout due to built in bootstrap diode.
Active-high input signal logic, resolves the startup and shutdown sequence constraint between
the control supply and control input, this provides fail-safe operation with direct connection
between the Mini DIP SPM and a 3.3V CPU or DSP. Additional external sequence logic is not
needed.
Integrated Functions
Inverter high-side IGBTs: Gate drive circuit, High-voltage isolated high-speed level shifting,
Control supply under-voltage (UV) protection
Inverter low-side IGBTs: Gate drive circuit, Short-circuit protection with soft shut-down control,
Control supply circuit under-voltage protection
Fault signaling (VFO): Corresponding to a SC fault (low-side IGBTs) or a UV fault
(low-side supply)
Input interface: 3.3V, 5V CMOS/LSTTL compatible, Schmitt trigger input, Active high.
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Mini DIP (SPM3) Application Note (2012-07-09)
5.
Absolute Maximum Ratings
5.1 Electrical Maximum Ratings
Turn-off Switching
The IGBTs incorporated into the Mini DIP SPM have a 600V volt VCES rating. The 500V VPN(Surge) rating
is obtained by subtracting the surge voltage (100V or less, generated by the Mini DIP SPM's internal stray
inductances ) from VCES. Moreover, the 450V VPN rating is obtained by subtracting the surge voltage (50V or
less, generated by the stray inductance between the Mini DIP SPM and the DC-link capacitor) from VPN(Surge).
Short-circuit Operation
In case of short-circuit turn-off, the 400V VPN(PROT) rating is obtained by subtracting the surge voltage
(100V or less, generated by the stray inductance between the Mini DIP SPM and the DC-link capacitor) from
VPN(Surge).
Table 5.1 Detail description of absolute maximum ratings (FSBB15CH60C case)
Item
Symbol
Rating
VPN
450V
Description
The maximum steady-state (non-switching mode) voltage between
Supply Voltage
P-N. A brake circuit is necessary if P-N voltage exceeds this value.
The maximum surge voltage (non-switching mode) between
Supply Voltage (surge)
VPN(surge)
500V
P-N. A snubber circuit is necessary if P-N surge voltage exceeds
this value.
Collector-emitter
VCES
600V
IC
15A
The sustained collector-emitter voltage of built-in IGBTs.
voltage
Each IGBT Collector
The maximum allowable DC continuous IGBT collector current at
current
Tc=25˚C.
The maximum junction temperature rating of the power chips
integrated within the Mini DIP SPM is 150˚C. However, to insure
Junction Temperature
TJ
-40 ~
safe operation of the Mini DIP SPM, the average junction
150C
temperature should be limited to 125˚C Although IGBT and FRD
chip will not be damaged right now at TJ = 150˚C, its power cycles
come to be decreased.
Under the conditions that Vcc=13.5 ~ 16.5V, non-repetitive, less
Self Protection
than 2s.
Supply Voltage Limit
VPN(PROT)
400V
The maximum supply voltage for safe IGBT turn off under SC
(Short Circuit
“Short Circuit” or OC “Over Current” condition. The power chip may
Protection Capability)
be damaged if supply voltage exceeds this specification.
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Mini DIP (SPM3) Application Note (2012-07-09)
Figure 5.1 shows that the normal turn-off switching operations can be performed satisfactorily at a
450V DC-link voltage, with the surge voltage between P and N pins (VPN(Surge)) is limited to under 500V. We
can also see the difference between the hard and soft turn-off switching operation from Fig. 5.2. The hard
turn-off of the IGBT causes a large overshoot (up to 100V). Hence, the DC-link capacitor supply voltage
should be limited to 400V to safely protect the Mini DIP SPM. A hard turn-off, with a duration of less than
approximately 2s, may occur in the case of a short-circuit fault. For a normal short-circuit fault, the
protection circuit becomes active and the IGBT is turned off very softly to prevent excessive overshoot
voltage. An overshoot voltage of 30~50V occurs for this condition. Figures 5.1-5.2 are the experimental
results of the safe operating area test. However, it is strongly recommended that the Mini DIP SPM should
not be operated under these conditions.
VPN(SURGE)@Tj=25oC
VPN(SURGE)@Tj=125oC
IC@Tj=125oC
IC@Tj=25oC
100V/div, 100ns/div, 5A/div
Figure 5.1 Normal current turn-off waveforms @ VPN=450V
VPN(SURGE)@ Hard off
VPN(SURGE)@ Soft off
IC@ Soft off
IC@ Hard off
100V/div, 20A/div, 200ns/div
Figure 5.2 Short-circuit current turn-off waveforms @ VPN=400V, Tj =125C
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Mini DIP (SPM3) Application Note (2012-07-09)
6. Interface Circuit
6.1 Input/Output Signal Connection
Figure 6.1 shows the I/O interface circuit between the CPU and Mini DIP SPM. Because the Mini DIP
SPM input logic is active-high and there are built-in pull-down resistors, external pull-up resistors are not
needed. VFO output is open collector configured. This signal should be pulled up to the positive side of the 5V
external logic power supply by a resistor of approximate 4.7k.
5V-Line
R PF =
SPM
4.7k
IN (UH) , IN (VH) , IN(W H)
IN (UL) , IN (VL) , IN (W L)
CPU
100
VFO
C PF =
1nF
1nF
CO M
Figure 6.1 Recommended CPU I/O Interface Circuit
Table 6.1 Maximum ratings of input and FO pins
Item
Symbol
Control Supply Voltage
VCC
Condition
Rating
Unit
20
V
-0.3 ~ 17
V
-0.3 ~ VCC+0.3
V
Applied between
VCC(H) – COM, VCC(L) – COM
Applied between
Input Signal Voltage
VIN
IN(UH), IN(VH), IN(WH) – COM
IN(UL), IN(VL), IN(WL) – COM
Fault Output Supply Voltage
VFO
Applied between VFO – COM
The input and fault output maximum rating voltages are shown in Table 6.1. Since the fault output is
open collector configured, it’s rating is VCC+0.3V, 15V supply interface is possible. However, it is
recommended that the fault output be configured with the 5V logic supply, which is the same as the input
signals. It is also recommended that the by-pass capacitors be placed at both the CPU and Mini DIP SPM
ends of the VFO, signal line as close as possible to each device. The RC coupling at each input (parts shown
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Mini DIP (SPM3) Application Note (2012-07-09)
dotted in Figure 6.1) might change depending on the PWM control scheme used in the application and the
wiring impedance of the application’s PCB layout.
SPM
1k
Level shift
circuit
INUH,INVH,INWH
Gate driver
5k(Typical)
INUL,INVL,INWL
Gate driver
5k(Typical)
Figure 6.2 Internal structure of signal input terminals
The Mini DIP SPM family employs active-high input logic. This removed the sequence restriction
between the control supply and the input signal during start-up or shutdown operation. Therefore it makes
the system fail-safe. In addition, pull-down resistors are built in to each input circuit. Thus, external pull-down
resistors are not needed reducing the required external component count. Furthermore, by lowering the turn
on and turn off threshold voltage of input signal as shown in Table 6.2, a direct connection to 3.3V-class
microprocessor or DSP is possible.
Table 6.2 Input threshold voltage ratings (at Vcc = 15V, Tj = 25℃)
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Turn on threshold voltage
VIN(ON)
IN(UH), IN(VH), IN(VH),– COM
2.8
-
-
V
Turn off threshold voltage
VIN(OFF)
IN(UL), IN(VL), IN(WL),– COM
-
-
0.8
V
As shown in Fig. 6.2, the Mini DIP SPM input signal section integrates a 5k(typical) pull-down resistor.
Therefore, when using an external filtering resistor between the CPU output and the Mini DIP SPM input
attention should be given to the signal voltage drop at the Mini DIP SPM input terminals to satisfy the turn-on
threshold voltage requirement. For instance, R = 100 and C=1nF for the parts shown dotted in Fig. 6.1.
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Mini DIP (SPM3) Application Note (2012-07-09)
6.2 General Interface Circuit Example
Figure 6.3 shows a typical application circuit of interface schematic with control signals connected
directly to a CPU.
15V line
(19) VB(W)
C6
C4
C1
WH
VCC
COM
IN
(17) IN(WH)
(20) VS(W)
(15) VB(V)
C5
VH
VCC
COM
IN
(13) IN(VH)
(16) VS(V)
(11) VB(U)
C
P
U
P
W (26)
W
V (25)
V
OUT
VS
VB
(14) VCC
C2
P (27)
VB
(18) VCC
OUT
VS
VB
(10) VCC
C3
C5
UH
VCC
COM
IN
(9) IN(UH)
C11
OUT
VS
U (24)
U
(12) VS(U)
5V line
(8) CSC
C(SC) OUT(WL)
(7) CFOD
R1
C7
Fo
C(FOD)
(6) VFO
(5) IN(WL)
WL
VL
UL
IN(WL) OUT(VL)
(4) IN(VL)
IN(VL)
15V line
IN(UL)
COM
VCC
15V
ZD1
C8
R3
N
(2) COM
(1) VCC
GND
NV (22)
(3) IN(UL)
5V line 15V line
5V
NW (23)
VFO
C9
OUT(UL)
VSL
NU (21)
R2
C10
Figure 6.3 Example of application circuit
Notes:
1.
2.
3.
4.
5.
6.
To avoid malfunction, the wiring of each input should be as short as possible. (less than 2-3cm)
By virtue of integrating an application specific type HVIC inside the Mini DIP SPM, direct coupling to
CPU terminals without any opto-coupler or transformer isolation is possible.
VFO output is an open collector output. This signal line should be pulled up to the positive side of the 5V
logic power supply with approximately 4.7k resistance. (reference Figure 6.1)
A CSP15 capacitance value approximately 7 times larger than bootstrap capacitor CBS is recommended.
The VFO output pulse width is determined by the value of an external capacitor (CFOD) between CFOD
(pin7) and COM (pin2). (Example : if CFOD = 33 nF, then tFO = 1.8ms (typ.)). Please refer to the
approximate equation of CFOD pin in page 16 for calculation method.
7.
The input signals are Active-high configured. There is a internal 5kpull-down resistor from each input
signal line to GND. When employing RC coupling circuits between the CPU and Mini DIP SPM select the
RC values such that the input signals will be compatible with the Mini DIP SPM turn-off/turn-on threshold
voltages.
To prevent protection function errors, the RF and CSC wiring should be as short as possible.
8.
The short-circuit protection time constant RFCSC should be set in the range of 1~2sec.
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Mini DIP (SPM3) Application Note (2012-07-09)
9. Each capacitor should be mounted as close to the pins of the Mini DIP SPM as possible.
10. To prevent surge destruction, the wiring between the filter capacitor and the P & Ground pins should be
as short as possible. The use of a high frequency non-inductive capacitor of around 0.1~0.22F between
the P & Ground pins is recommended. In addition to reducing local voltage spikes, the placement and
quality of this capacitor will have a direct impact on both conducted and radiated EMI.
11. Relays are used in almost all home appliances electrical equipment. These relays should be kept a
sufficient distance from the CPU to prevent electromagnetic radiation from impacting the CPU.
12. Excessively large inductance due to long wiring patterns between the shunt resistor and Mini DIP SPM
will cause large surge voltage that might damage the Mini DIP SPM’s internal ICs. Therefore, the wiring
between the shunt resistor and Mini DIP SPM should be as short as possible. Additionally, CSPC15
(more than 1F) should be mounted as close to the pins of the Mini DIP SPM as possible.
13. Opto-coupler can be used for electric (galvanic) isolation. When opto-couplers are used, attention should
be taken to the signal logic level and opto-coupler delay time. Also, since the VFO output current
capability is 1mA (max), it cannot drive an opto-coupler directly. A buffer circuit should be added in the
primary side of the opto-coupler.
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Mini DIP (SPM3) Application Note (2012-07-09)
6.3 Recommended Wiring of Shunt Resistor and Snubber Capacitor
External current sensing resistors are applied to detect short-circuit or phase currents. A long wiring
patterns between the shunt resistors and SPM will cause excessive surges that might damage the Mini DIP
SPM ’s internal ICs and current detection components, and may also distort the sensing signals. To decrease
the pattern inductance, the wiring between the shunt resistors and SPM should be as short as possible.
As shown in the Fig. 6.4, snubber capacitors should be installed in the right location so as to suppress
surge voltages effectively. Generally a 0.1～0.22F snubber is recommended. If the snubber capacitor is
installed in the wrong location ‘A’ as shown in the Fig. 6.4, the snubber capacitor cannot suppress the surge
voltage effectively. If the capacitor is installed in the location ‘B’, the charging and discharging currents
generated by wiring inductance and the snubber capacitor will appear on the shunt resistor. This will impact
the current sensing signal and the SC protection level will be somewhat lower than the calculated design
value. The “B” position surge suppression effect is greater than the location ‘A’ or ‘C’. The ‘C’ position is a
reasonable compromise with better suppression than in location ‘A’ without impacting the current sensing
signal accuracy. For this reason, the location ‘C’ is generally used.
Incorrect position of
Snubber Capacitor
Correct position of
Snubber Capacitor
P
C
A
Capacitor
Bank
B
SPM
Wiring Leakage
Inductance
Nu,Nv,Nw
Please make the connection point
as close as possible to the
terminal of shunt resistor
Wiring inductance should
be less than 10nH.
For example,
width > 3mm,
thickness = 100m,
length < 17mm
in copper pattern
COM
Shunt
Resistor
Figure 6.4 Recommended wiring of shunt resistor and snubber capacitor
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Mini DIP (SPM3) Application Note (2012-07-09)
7. Function and Protection Circuit
7.1 SPM Functions versus Control Power Supply Voltage
Control and gate drive power for the Mini DIP SPM is normally provided by a single 15Vdc supply that
is connected to the module Vcc and COM terminals. For proper operation this voltage should be regulated to
15V 10% and its current supply should be larger than 60mA for SPM only. Table 7.1 describes the behavior
of the SPM for various control supply voltages. The control supply should be well filtered with a low
impedance electrolytic capacitor and a high frequency decoupling capacitor connected closely at the Mini
DIP SPM ’s pins.
High frequency noise on the supply might cause the internal control IC to malfunction and generate
erroneous fault signals. To avoid these problems, the maximum ripple on the supply should be less than ±
1V/s. In addition, it may be necessary to connect a 24V, 0.5W zener diode across the control supply to
prevent surge destruction under severe conditions.
The voltage at the module’s COM terminal is different from that at the N power terminal by the drop
across the sensing resistor. It is very important that all control circuits and power supplies be referred to this
point and not to the N terminal. If circuits are improperly connected, the additional current flowing through the
sense resistor might cause improper operation of the short-circuit protection function. In general, it is best
practice to make the common reference (COM) a ground plane in the PCB layout.
The main control power supply is also connected to the bootstrap circuits that are used to establish the
floating supplies for the high side gate drives.
When control supply voltage (VCC and VBS) falls down under UVLO (Under Voltage Lock Out) level,
IGBT will turn OFF while ignoring the input signal. To prevent noise from interrupting this function, built-in
3sec filter is installed in both HVIC and LVIC.
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Mini DIP (SPM3) Application Note (2012-07-09)
Table 7.1 Mini DIP SPM Functions versus Control Power Supply Voltage
Control Voltage Range [V]
Mini DIP SPM Function Operations
Control IC does not operate. Under voltage lockout and fault output do not operate.
0~4
dV/dt noise on the main P-N supply might trigger the IGBTs.
Control IC starts to operate. As the under voltage lockout is set, control input signals are
4 ~ 12.5
blocked and a fault signal Fo is generated.
Under voltage lockout is reset. IGBTs will be operated in accordance with the control
12.5 ~ 13.5
gate input. Driving voltage is below the recommended range so VCE(sat) and the
switching loss will be larger than that under normal condition.
13.5 ~ 16.5 for VCC
Normal operation. This is the recommended operating condition.
13 ~ 18.5 for VBS
IGBTs are still operated. Because driving voltage is above the recommended range,
16.5 ~ 20 for VCC
18.5 ~ 20 for VBS
Over 20
IGBTs’ switching is faster. It causes increasing system noise. And peak short circuit
current might be too large for proper operation of the short circuit protection.
Control circuit in the Mini DIP SPM might be damaged.
7.2 Under-Voltage Protection
The LVIC has an under voltage lockout function to protect low side IGBTs from operation with
insufficient gate driving voltage. A timing chart for this protection is shown in Fig. 7.1.
a1 : Control supply voltage rises :
After the voltage rises UVCCR, the circuits start to operate when next input is applied
a2 : Normal operation : IGBT ON and carrying current.
a3 : Under voltage detection ( UVCCD)
a4 : IGBT OFF in spite of control input condition
a5 : Fault output operation starts
a6 : Under voltage reset ( UVCCR)
a7 : Normal operation : IGBT ON and carrying current
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Mini DIP (SPM3) Application Note (2012-07-09)
Input Signal
Protection
Circuit State
RESET
SET
RESET
UVCCR
Control
Supply Voltage
a1
a6
UVCCD
a3
a2
a7
a4
Output Current
a5
Fault Output Signal
Figure 7.1 Timing chart of low-side under-voltage protection function
The HVIC has an under voltage lockout function to protect the high side IGBT from insufficient gate
driving voltage. A timing chart for this protection is shown in Figure 7.2. A Fo alarm is not given for low HVIC
bias conditions.
b1 : Control supply voltage rises: After the voltage reaches UVBSR, the circuits start to operate when
next input is applied.
b2 : Normal operation: IGBT ON and carrying current.
b3 : Under voltage detection (UVBSD).
b4 : IGBT OFF in spite of control input condition, but there is no fault output signal.
b5 : Under voltage reset (UVBSR)
b6 : Normal operation: IGBT ON and carrying current
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Mini DIP (SPM3) Application Note (2012-07-09)
Input Signal
Protection
Circuit State
RESET
SET
RESET
UVBSR
b5
b1
Control
Supply Voltage
UVBSD
b3
b6
b2
b4
Output Current
High-level (no fault output)
Fault Output Signal
Figure 7.2 Timing chart of high-side under-voltage protection function
7.3 Short-Circuit Protection
7.3.1 Timing chart of Short Circuit (SC) Protection
The LVIC has a built-in short circuit function. This IC monitors the voltage to the CSC pin and if this
voltage exceeds the VSC(ref), which is specified in the devices data sheets, then a fault signal is asserted and
the lower arm IGBTs are turned off. Typically the maximum short circuit current magnitude is gate voltage
dependant. A higher gate voltage results in a larger short circuit current. In order to avoid this potential
problem, the maximum short circuit trip level is generally set to below 1.7times the nominal rated collector
current. The LVIC short circuit protection-timing chart is shown in Figure 7.3.
(with the external shunt resistance and RC connection)
c1 : Normal operation: IGBT ON and carrying current.
c2 : Short circuit current detection (SC trigger).
c3 : Hard IGBT gate interrupt.
c4 : IGBT turns OFF softly.
c5 : Fault output timer operation starts:
The pulse width of the fault output signal is set by the external capacitor CFO.
c6 : Input “L” : IGBT OFF state.
c7 : Input “H”: IGBT ON state, but during the active period of fault output the IGBT doesn’t turn ON.
c8 : IGBT OFF state
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Mini DIP (SPM3) Application Note (2012-07-09)
Lower arms
control input
c6
Protection
circuit state
SET
Internal IGBT
Gate-Emitter Voltage
c7
RESET
c4
c3
c2
SC
c1
c8
Output Current
SC Reference Voltage
Sensing Voltage
of the shunt
resistance
Fault Output Signal
c5
CR circuit time
constant delay
Figure 7.3 Timing chart of short-circuit protection function
7.3.2 Selecting Current Sensing Shunt Resistor
Figure 7.4 shows an example circuit of the SC protection using 1-shunt resistor. The line current on the
N side DC-link is detected and the protective operation signal is passed through the RC filter. If the current
exceeds the SC reference level, all the gates of the N-side three-phase IGBTs are switched to the OFF state
and the Fo fault signal is transmitted to the CPU. Since SC protection is non-repetitive, IGBT operation
should be immediately halted when the Fo fault signal is given.
The internal protection circuit triggers off under SC condition by comparing the external shunt voltage
to the reference SC trip voltage in the LVIC. The drive IC then interrupts low-side IGBT gates to stop IGBT
operation. The value of current sensing resistor is calculated by the following expression:
RSHUNT
VSC ( REF )
I SC
where VSC ( REF ) is the SC reference voltage of the LVIC.
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Mini DIP (SPM3) Application Note (2012-07-09)
15V-Line
Mini DIP SPM
VCC
DC Current
Isc
RF
CSC
+
Rshunt
+
CSC
VSEN
VCSC
-
-
COM
Figure 7.4 Example of Short Circuit protection circuit with 1-shunt resistor
An RC filter (reference RF CSC above) is necessary to prevent noise related SC circuit malfunction.
The RC time constant is determined by the applied noise time and the IGBT withstand voltage capability. It is
recommended to be set in the range of 1.5 ~ 2s.
When the external shunt resistor voltage drop exceeds the SC protection level, this voltage is applied
to the CSC pin via the RC filter. The filter delay time (t1) is the time required for the CSC pin voltage to rises to
the referenced SC protection level. Table 7.2 shows the specification of the SC protection level. The IC has
an internal noise elimination logic filter delay (t2) of 500nsec. The typical IC transfer time delay (t3) should be
considered, too. Please, refer to the table 7.3.
Table 7.2 Specification of SC protection reference level ’ VSC(REF)’
Item
Min.
Typ.
Max.
Unit
SC trip level VSC(REF)
0.45
0.5
0.55
V
Table 7.3 Internal delay time of SC protection circuit
Item
Min.
Typ.
Max.
Unit
Internal filter delay time (t2)
-
0.5
0.7
sec
IC transfer delay time (t3)
-
0.9
1.3
sec
Therefore the total time from the detection of the SC trip current to the gate off of the IGBT becomes:
TTOTAL = t1 + t2 + t3
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Mini DIP (SPM3) Application Note (2012-07-09)
15V-Line
Mini DIP SPM
Other phases
sensing block
VCC
ILeakage = 500nA
RF1
+ VF
-
RF2
CSC
+
Rshunt
VSEN
-
CF1
+
VCSC CSC
RCSC
-
COM
Figure 7.5 Example of Short Circuit protection circuit with 3-shunt resistor
The 3-shunt resistor circuit is more complicated and has more considerations than the 1-shunt resistor
circuit. The 3-shunt circuit is popular since it permits detection of individual phase currents. The circuit is very
cost effective, simple and provides good current sensing performance.
Figure 7.5 shows typical circuit for short-circuit detection using diodes. It should be noted that this
circuit is not adequate for the precise over-current detection due to dispersion and temperature dependency
of VF. Also, there are additional considerations when using this circuit as follows :
1.
The SC sensing signal delay time is increased. The RF1 x CF1 time constant delay (t4) is
added so the total delay time becomes:
TTOTAL = t1 + t2 + t3 + t4
2.
The added diode blocks the IC leakage current (approximately 500nA) from Csc pin. If this
current is applied to the capacitor Csc, the Vcsc will be increased to a somewhat higher
value and causes SPM to stop gating even under normal conditions. In order to compensate
for this corruption of SC current sensing voltage, Rcsc must be placed in parallel with Csc.
The recommended value of Rcsc is approximately 47k.
3.
For the short circuit state, the diode drop voltage has to be considered to set the SC
protection reference level. The equation is as illustrated below.
VSEN = Vcsc + VF
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Mini DIP (SPM3) Application Note (2012-07-09)
7.4 Fault Output Circuit
Table 7.4 Fault-output Maximum Ratings
Item
Symbol
Condition
Rating
Unit
Fault Output Supply Voltage
VFO
Applied between VFO-COM
-0.3~ VCC+0.3
V
Fault Output Current
IFO
Sink current at VFO pin
5
mA
Table 7.5 Electric Characteristics
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Fault Output
VFOH
VSC = 0V, VFO Circuit: 4.7k to 5V Pull-up
4.5
-
-
V
Supply Voltage
VFOL
VSC = 1V, VFO Circuit: 4.7k to 5V Pull-up
-
-
0.8
V
Because FO terminal is an open collector type, it should be pulled up to 5V or 15V level via a pull-up
resistor. The resistor has to satisfy the above specifications.
0.30
0.25
VFO [V]
0.20
0.15
0.10
0.05
0.00
0
1
2
3
4
5
IFO [mA]
Figure 7.6 Voltage-current characteristics of VFO terminal
5V
RP
VFO
MCU
SPM
GND
COM
Figure 7.7 VFO terminal wiring
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7.5 TSD (Thermal Shut-Down) Protection
The LVIC has a built-in TSD(Thermal Shut-Down) function. This function detects LVIC temperature
(not IGBT junction temperature). Purpose of this protection is to detect abnormal increase of case
temperature. Cooling fan stop or loose fixing of heat sink will cause it. So this TSD function will not work
effectively in the case of rapid temperature rise like motor lock condition or over current. (This protection
measures LVIC temperature, so it cannot respond to rapid temperature rise of IGBT & FRD)
This TSD function detects LVIC temperature and if LVIC temperature exceeds the Td (Td : Typical
o
160 C), then a fault signal is asserted and the lower arm IGBTs are turned off. And then if LVIC temperature
decrease under Tr (Tr : Typical 155oC), then a fault signal is released. The protection-timing chart is shown in
Figure 7.8.
Td : TSD Detection
Tr : TSD Reset
Tdr : Hysteresis
Td
LVIC
Temperature
Tr
ΔTdr (Hysteresis)
Fault Out
Signal
Control Supply
Voltage
SET
RESET
SET
RESET
+15V
Figure 7.8 Timing chart of LVIC TSD function
8. Bootstrap Circuit
8.1 Operation of Bootstrap Circuit
The VBS voltage, which is the voltage difference between VB (U, V, W) and VS (U, V, W), provides the supply
to the HVICs within the Mini DIP SPM. This supply must be in the range of 13.0~18.5V to ensure that the
HVIC can fully drive the high-side IGBT. The Mini DIP SPM includes an under-voltage detection function for
the VBS to ensure that the HVIC does not drive the high-side IGBT, if the VBS voltage drops below a specified
voltage (refer to the datasheet). This function prevents the IGBT from operating in a high dissipation mode.
There are a number of ways in which the VBS floating supply can be generated. One of them is the
bootstrap method described here. This method has the advantage of being simple and inexpensive. However,
the duty cycle and on-time are limited by the requirement to refresh the charge in the bootstrap capacitor.
The bootstrap supply is formed by a combination of an bootstrap diode, resistor and capacitor as shown in
Figure 8.1. The current flow path of the bootstrap circuit is shown in Fig. 8.1. When VS is pulled down to
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Mini DIP (SPM3) Application Note (2012-07-09)
ground (either through the low-side or the load), the bootstrap capacitor (CBS) is charged through the
bootstrap diode (DBS) and the resistor (RBS) from the VCC supply.
8.2 Initial Charging of Bootstrap Capacitor
An adequate on-time duration of the low-side IGBT to fully charge the bootstrap capacitor is required
for initial bootstrap charging. The initial charging time (tcharge) can be calculated from the following equation:
tch arg e CBS RBS
VCC
ln(
)
VCC VBS (min) V f VLS
1
(8.1)
Vf = Forward voltage drop across the bootstrap diode
VBS(min) = The minimum value of the bootstrap capacitor
VLS = Voltage drop across the low-side IGBT or load
= Duty ratio of PWM
P
D BS
R BS
C BS
V cc
VB
IN
HO
COM
VS
VPN
VC C
U , V, W
V cc
V in(L)
IN
V cc
VBS
O ut
COM
ON
N
(a) Bootstrap circuit
V IN (L)
(b) Timing chart of initial bootstrap charging
Figure 8.1 Bootstrap circuit operation and initial charging
8.3 Selection of a Bootstrap Capacitor
The bootstrap capacitance can be calculated by:
C BS
I leak t
V
Where t = maximum ON pulse width of high-side IGBT
V = the allowable discharge voltage of the CBS.
Ileak= maximum discharge current of the CBS mainly via the following mechanisms :
Gate charge for turning the high-side IGBT on
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(8.2)
Mini DIP (SPM3) Application Note (2012-07-09)
Quiescent current to the high-side circuit in the IC
Level-shift charge required by level-shifters in the IC
Leakage current in the bootstrap diode
CBS capacitor leakage current (ignored for non-electrolytic capacitors)
Bootstrap diode reverse recovery charge
Practically, 1mA of Ileak is recommended for Mini DIP SPM. By taking consideration of dispersion and
reliability, the capacitance is generally selected to be 2~3 times of the calculated one. The CBS is only
charged when the high-side IGBT is off and the VS voltage is pulled down to ground. Therefore, the on-time
of the low-side IGBT must be sufficient to ensure that the charge drawn from the CBS capacitor can be fully
replenished. Hence, inherently there is a minimum on-time of the low-side IGBT (or off-time of the high-side
IGBT).
The bootstrap capacitor should always be placed as close to the pins of the SPM as possible. At least
one low ESR capacitor should be used to provide good local de-coupling. For example, a separate ceramic
capacitor close to the SPM is essential, if an electrolytic capacitor is used for the bootstrap capacitor. If the
bootstrap capacitor is either a ceramic or tantalum type, it should be adequate for local decoupling.
8.4 Built in Bootstrap Diode including around 15 Resistance characteristics
From Mini DIP SPM released in Q1, 2007, built in bootstrap diode will be incorporated. When high side
IGBT or diode conducts, this bootstrap diode block up the entire bus voltage. In Mini DIP SPM, the maximum
rating of power supply is 450V. The actual voltage applied on the diode is 500V by adding a surge voltage of
about 50V. Hence the withstand voltage of bootstrap diode is more than 600V include 100V margin.
Recovery characteristics are less than max. 120ns to minimize the amount of charge that is fed back from
the bootstrap capacitor into the VCC supply. Similarly, the high voltage reverse leakage current is important if
the capacitor has to store a charge for long periods of time.
Specially, built in bootstrap diode includes around 15 resistance characteristics. This characteristics
are used to slow down the dVBS/dt and it also determines the time to charge the bootstrap capacitor.
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Mini DIP (SPM3) Application Note (2012-07-09)
Figure 8.2 VF-IF curve of two bootstrap diode
8.5 Charging and Discharging of the Bootstrap Capacitor during PWM-Inverter
Operation
The bootstrap capacitor (CBS) charges through the built in bootstrap diode from the VCC supply when
the high-side IGBT is off, and the VS voltage is pulled down to ground. It discharges when the high-side IGBT
is on.
Example 1: Selection of the Initial Charging Time
An example of the calculation of the minimum value of the initial charging time is given with reference
to equation (8.1).
Conditions:
CBS = 22F
Duty Ratio of PWM()= 0.5
DBS = built in bootstrap diode including around 15 resistance characteristics
VCC = 15V
Vf (Forward voltage drop across the bootstrap diode)= 0.5V
VBS (min) (The minimum voltage of the bootstrap capacitor)= 13V
VLS (Voltage drop across the low-side IGBT or load)= 0.7V
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Mini DIP (SPM3) Application Note (2012-07-09)
tch arg e 22 F 15
1
15V
ln(
) 1.9ms
0 .5
15V 13V 0.5V 0.7V
In order to ensure safety, it is recommended that the charging time must be at least three times longer
than the calculated value.
Example 2: The Minimum Value of the Bootstrap Capacitor
Conditions:
V=1V
t=5msec
Ileak=1mA
C BS
1mA 0.005s
5F
1V
The calculated bootstrap capacitance is 5F. By taking consideration of dispersion and reliability, the
capacitance is generally selected to be 2-3 times of the calculated one. Note that this result is only an
example. It is recommended that you design a system by taking consideration of the actual control pattern
and lifetime of components.
8.6 Recommended Boot Strap Operation Circuit and Parameters
Figure 8.3 is the recommended bootstrap operation circuit and parameters.
These Values depend on PWM Control Algorithm
One-Leg Diagram of SPM
P
15V-Line
22uF
0.1uF
Vcc
VB
IN
HO
COM
VS
Inverter
Output
Vcc
1000uF
1uF
IN
COM
OUT
V SL
N
Figure 8.3 Recommended Boot Strap Operation Circuit and Parameters
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Mini DIP (SPM3) Application Note (2012-07-09)
9. Power Loss and Dissipation
9.1 Power Loss of SPM
The total power losses in the Mini DIP SPM are composed of conduction and switching losses in the
IGBTs and FRDs. The loss during the turn-off steady state can be ignored because it is very small amount
and has little effect on increasing the temperature in the device. The conduction loss depends on the dc
electrical characteristics of the device i.e. saturation voltage. Therefore, it is a function of the conduction
current and the device’s junction temperature. On the other hand the switching loss is determined by the
dynamic characteristics like turn-on/off time and over-voltage/current. Hence, in order to obtain the accurate
switching loss, we should consider the DC-link voltage of the system, the applied switching frequency and
the power circuit layout in addition to the current and temperature.
In this chapter, based on a PWM-inverter system for motor control applications, detailed equations are
shown to calculate both losses of the Mini DIP SPM. They are for the case that 3-phase continuous
sinusoidal PWM is adopted. For other cases like 3-phase discontinuous PWMs, please refer to the paper
"Minimum-Loss Strategy for three-Phase PWM Rectifier, IEEE Transactions on Industrial Electronics, Vol. 46,
No. 3, June, 1999 by Dae-Woong Chung and Seung-Ki Sul”.
9.1.1 Conduction Loss
The typical characteristics of forward drop voltage are approximated by the following linear equation
for the IGBT and the diode, respectively.
vI VI RI i
(9.1)
vD VD RD i
VI = Threshold voltage of IGBT
VD = Threshold voltage of diode
RI = on-state slope resistance of IGBT
RD = on-state slope resistance of diode
Assuming that the switching frequency is high, the output current of the PWM-inverter can be assumed
to be sinusoidal. That is,
i I peak cos( )
(9.2)
Where is the phase-angle difference between output voltage and current. Using equations (9.1), the
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Mini DIP (SPM3) Application Note (2012-07-09)
conduction loss of one IGBT and diode can be obtained as follows.
2
VI I peak
Pcon.I
2
cos( )d
RI I peak
2
Pcon.D
2
VD I peak
2
2 2
cos
2
2
( )d
(9.3)
2
(1 ) cos( )d
RD I peak
2
2
2 2
(1 ) cos
2
( )d
(9.4)
2
where is the duty cycle in the given PWM method.
1 MI cos
2
(9.5)
where MI is the PWM modulation index (MI, defined as the peak phase voltage divided by the half of
dc link voltage). Finally, the integration of equation (9.3) and (9.4) gives
Pcon Pcon. I Pcon. D
I peak
2
(VI VD )
(9.6)
I peak
8
(VI VD ) MI cos
I peak
8
2
( RI R D )
I peak
2
3
( RI RD ) MI cos
It should be noted that the total inverter conduction losses are six times of the Pcon.
9.1.2 Switching Loss
Different devices have different switching characteristics and they also vary according to the handled
voltage/current and the operating temperature/frequency. However, the turn-on/off loss energy (Joule) can be
experimentally measured indirectly by multiplying the current and voltage and integrating over time, under a
given circumstance. Therefore the linear dependency of a switching energy loss on the switched-current is
expressed during one switching period as follows.
Swtitching
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energy
loss ( E I E D ) i
[ joule]
(9.7)
E I E I .ON E I .OFF
(9.8)
E D E D .ON E D.OFF
(9.9)
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Mini DIP (SPM3) Application Note (2012-07-09)
where, EI i is the switching loss energy of the IGBT and ED i is for the diode. EI and ED can be
considered a constant approximately.
As mentioned in the above equation (9.2), the output current can be considered a sinusoidal waveform
and the switching loss occurs every PWM period in the continuous PWM schemes. Therefore, depending on
the switching frequency of fSW, the switching loss of one device is the following equation (9.10).
1
Psw
2
2
(E
I
E D ) i f sw d
2
( E I ED ) f sw I peak
2
2
cos( )d
( E I ED ) f sw I peak
2
(9.10)
where EI is a unique constant of IGBT related to the switching energy and different IGBT has different
EI value. ED is one for diode. Those should be derived by experimental measurement. From equation (9.10),
it should be noted that the switching losses are a linear function of current and directly proportional to the
switching frequency.
9.2 Thermal Impedance
9.2.1 Overview
Semiconductor devices are very sensitive to junction temperature, i.e., as the junction temperature
increases, the operating characteristics of a device are altered from normal, and the failure rate increases
exponentially. This makes the thermal design of the package a very important factor in the device
development stage, and also in an application field.
To gain insight into the device’s thermal performance, it is normal to introduce thermal resistance,
which is defined as the difference in temperature between two closed isothermal surfaces divided by the total
heat flow between them. For semiconductor devices, two temperatures are junction temperature, Tj and
reference temperature, Tx, and the amount of heat flow is equal to the power dissipation of a device during
operation. The selection of a reference point is arbitrary, but usually the hottest spot on the back of a device
on which a heat sink is attached is chosen. This is called junction-to-case thermal resistance, Rjc. When the
reference point is an ambient temperature, this is called junction-to-ambient thermal resistance, Rja. Both
the thermal resistances are used for the characterization of a device’s thermal performance. Rjc is usually
used for heat sink carrying devices while Rja is used in other cases. Figure 9.1 shows a thermal network of
heat flow from junction-to-ambient for the SPM including a heat sink. The dotted component of Rca can be
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Mini DIP (SPM3) Application Note (2012-07-09)
ignored due to its large value.
Tj
Tc
Th
R θjc
PD
C jc
Ta
R θch
C ch
R θca
B eing ig no red
R θha
C ha
Transient im p ed ance
o f each sectio n
Figure 9.1 Transient thermal equivalent circuit with a heatsink.
The thermal resistance of the SPM is defined in the following equation,
Rjc
T j Tc
(9.11)
PD
where Rjc (oC/W) is the junction-to-case thermal resistance, and PD(W), Tj (oC) and Tc (oC) are power
dissipation per device, junction temperature and case reference temperature, respectively. By replacing Tc
with Ta (ambient temperature), the junction-to-ambient thermal resistance Rja can be obtained as following,
Rja
T j Ta
PD
(9.12)
where Rja indicates the total thermal performance of the SPM including the heat sink. Basically Rja is
a serial summation of various thermal resistances, Rjc, Rch and Rha.
Rja Rjc Rch Rha
(9.13)
where Rch is contact thermal resistance due to the thermal grease between the package and the heat
sink, and Rha is heat sink thermal resistance, respectively. From the equation (9.13), it is clear that
minimizing Rch and Rha is an essential application factor to maximize the power carrying ability of the SPM
as well as the minimizing of Rjc itself. An infinite heat sink will result if Rch and Rha are reduced to zero and
the case temperature Tc is locked at the fixed ambient temperature Ta. Usually, the value of Rch is
proportional to the thermal grease thickness and governed by the skill at the assembly site, while Rha can be
handled to some extent by selecting an appropriate heat sink.
In practical operation, the power loss PD is cyclic and therfore the transient RC equivalent circuit shown
in Fig. 9.1 should be considered. For pulsed power loss, the thermal capacitance effect delays the rise in
junction temperature, and thus permits a heavier loading of the SPM. Figure 9.2 shows the normalized
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Mini DIP (SPM3) Application Note (2012-07-09)
thermal impedance curves of FSBB30CH60C, FSBB15CH60C, FSBF10CH60B and FSBF3CH60B. The
thermal resistance goes into saturation in about 10 seconds. Other kinds of SPM also show similar
characteristics.
2.0
2.0
Zth(J-C)_IGBT
1.6
1.6
1.4
1.4
1.2
1.2
1.0
0.8
1.0
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
1E-6
1E-5
1E-4
1E-3
Zth(J-C)_FRD
1.8
Zth(J-C)
Zth(J-C)
1.8
0.01
0.1
1
10
0.0
1E-6
100
1E-5
1E-4
1E-3
Pulse Duration [sec]
0.01
0.1
1
10
100
1
10
100
Pulse Duration [sec]
(a) FSBB30CH60C
3.0
4.0
Zth(J-C)_IGBT
2.5
Zth(J-C)_FRD
3.5
3.0
2.0
Zth(J-C)
Zth(J-C)
2.5
1.5
2.0
1.5
1.0
1.0
0.5
0.5
0.0
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
10
0.0
1E-6
100
1E-5
1E-4
1E-3
Pulse Duration [sec]
0.01
0.1
Pulse Duration [sec]
(b) FSBB15CH60C
7
7
Zth(J-C)_IGBT
5
5
4
4
3
3
2
2
1
1
0
1E-6
1E-5
1E-4
1E-3
Zth(J-C)_FRD
6
Zth(J-C)
Zth(J-C)
6
0.01
0.1
1
10
0
1E-6
100
1E-5
Pulse Duration [sec]
1E-4
1E-3
0.01
0.1
1
10
100
Pulse Duration [sec]
(c) FSBF10CH60B
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Mini DIP (SPM3) Application Note (2012-07-09)
8
8
Zth(J-C)_IGBT
6
6
5
5
4
3
4
3
2
2
1
1
0
1E-6
1E-5
1E-4
1E-3
Zth(J-C)_FRD
7
Zth(J-C)
Zth(J-C)
7
0.01
0.1
1
10
0
1E-6
100
1E-5
Pulse Duration [sec]
1E-4
1E-3
0.01
0.1
1
10
100
Pulse Duration [sec]
(d) FSBF3CH60B
Figure 9.2 Normalized Thermal impedance curves.
9.2.2 Measurement Method
During the thermal resistance test, Tj, Tc (or Ta) and PD should be measured. Since Tc, Ta and PD can
be measured directly, the only unknown constant is the junction temperature, Tj. The Electrical Test Method
(ETM) is widely used to measure the junction temperature. The ETM is a test method using the relationship
between forward drop voltage and junction temperature. This relationship is an intrinsic electro-thermal
property of semiconductor junctions, and is characterized by a nearly linear relationship between the
forward-biased drop voltage and the junction temperature, when a constant forward-biased current (sense
current) is applied. This voltage drop of the junction is called Temperature Sensitive Parameter (TSP). Figure
9.3 illustrates the concept of measuring the voltage drop vs. junction temperature relationship for a diode
junction. The device under test (DUT) is embedded in hot fluid to heat DUT up to desired temperatures.
Voltage
M easure
Sense
Current
Thermocouple
attached to case
D evice
S tirred
D ielectic B ath
Heater
Figure 9.3 Illustration of the bath method for TSP measurement
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Tj
Tj=m*VX+To
VX
Figure 9.4 Typical example of a TSP Plot with constant sense current
When the DUT attains thermal equilibrium with the hot fluid, a sense current is applied to the junction.
Then the voltage drop across the junction is measured as a function of the junction temperatures. The
amount of sense current should be small enough not to heat the DUT, for instance, 1mA, 10mA depending
on the device type. The measurements are repeated over a specific temperature range with some specified
temperature steps. Figure 9.4 shows a typical result.
The relationship between the junction temperature and voltage drop at a given temperature can be
expressed as shown in the following equation.
T j m VX To
(9.14)
The slope, m(℃/V) and the temperature ordinate-intercept, To(V) are used to quantify this straight line
relationship. The reciprocal of the slope is often referred to as the "K factor (V/oC)". In this case, Vf(V) is the
TSP. For semiconductor junctions, the slope m of the calibrating straight line in Fig. 9.4 is always negative,
i.e., the forward conduction voltage decreases with increasing junction temperature. This process of
obtaining equation (9.14) is called the calibration procedure for a given device.
During the thermal resistance measurement test, the junction temperature can be estimated by
measuring the voltage drop at a given sense current during the calibration procedure and by using equation
(9.14). The TSP varies from device to device, since a specific device does not have the diode voltage TSP.
But the transistor saturation voltage can be used in that case. For instance, the gate turn-on voltage can be
used as the TSP for an IGBT or a MOSFET.
9.2.3 Measurement Procedures
The thermal resistance test begins by applying a continuous power of known current and voltage to the
DUT. The continuous power heats up the DUT to a thermally equilibrated state. While the device is heating, a
continuous train of sampling pulses monitors the TSP, i.e., the voltage drop or the same as the junction
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Mini DIP (SPM3) Application Note (2012-07-09)
temperature. The TSP sampling pulse must provide a sense current equal to that used during the calibration
procedure for obtaining equation (9.14). While monitoring the TSP, adjust the applied power so as to insure a
sufficient rise in Tj. Adjusting the applied power to achieve a Tj increase of about 100℃ above the reference
temperature will generate enough temperature difference to ensure a good measurement resolution. A
typical example is shown in Fig. 9.5.
Heating
Power
Train of heating pulse with 80ms interval and
sensing pulses with 100us is given typically
80ms
100us
Time
Figure 9.5 Example of a power and sample pulses train during the Rjc measurement of a SPM-IGBT
The TSP sampling time must be very short so as not to allow for any appreciable cooling of the
junction prior to re-applying power. The power and sensing pulse train shown in Fig. 9.5 has a duty cycle of
99.9%, which for all practical purposes is considered to be continuous power. Obviously, most of the total
power is applied to the DUT in Fig. 9.6.
Once Tj reaches thermal equilibrium, its value along with the reference temperature Tc and applied
power P is recorded. Using the measured values and equation (9.11), the junction-to-case thermal resistance
Rjc can be estimated. Rjc here indicates the ability of a device to dissipate power in an ideal environment,
that is, mounted with an infinite or temperature-controlled heat sink.
Figure 9.7 shows the thermal resistance measurement environment for SPMs. The SPM is placed on a
heat sink having a large heat carrying capacity. Thermal grease is applied between the SPM and heat sink to
prevent an air gap.
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Mini DIP (SPM3) Application Note (2012-07-09)
Heating
Circuit
VH
Sensing
Circuit
VX
D evice
Sense
Current
Heating
Current, IH
Tj = m*VX + To
Rjc = (Tj-Tc) / (VH*IH)
Figure 9.6 Illustration of the thermal resistance test method concept
Air Pressure ON / OFF Switch
Pneumatic Heat Sunk Fixture
Air Pressure Gauge
Voltage : 120VAC, 60HZ
Air Pressure Controller
Case Size : 275 x 190 x 125 [㎣]
External Heat Sink Size: 150 x 110 x 7[㎣]
SPM
7mm
Cooling Fan
Thermo
-couple
125mm
Air Blowing
Figure 9.7 The thermal measurement environment of the SPM.
A thermocouple is inserted through the heat sink and pressed against the underside of the SPM to
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Mini DIP (SPM3) Application Note (2012-07-09)
record the SPM surface temperature. Although there is no stipulation on the thermocouple location on which
the reference temperature (Tc here) needs to be measured, it is recommended that the ideal location is the
hottest point. In this note, the SPM center or the heat sink center was chosen.
The thermocouple needs to make a good thermal contact with its reference location. Thermal grease
and appropriate clamping pressure are needed as shown in Fig. 9.7.
9.3 Temperature Rise Considerations and Calculation Example
The result of loss calculation using the typical characteristics is shown in Figure 9.8 as “Effective
current versus carrier frequency characteristics”. The conditions are follows.
Conditions : VPN=300V, VCC=VBS=15V, VCE(sat)=typical, Switching loss=typical, Tj=150C, Tc=125C,
Rth(j-c) = Max., M.I.=1.0, P.F=0.8, 3-phase continuous PWM modulation, 60Hz sine waveform output.
Effective Load Current IO [Arms]
100
10
FSBB30CH60C
FSBB20CH60C
FSBB15CH60C
FSBF15CH60BT
FSBF10CH60B
1
1
2
3
4
5
6
7 8 9 10
20
30
Switching Frequency FSW [kHz]
Figure 9.8 Effective current－carrier frequency characteristics
Note:
The above characteristics may vary in the different control schemes and motor drive types.
Figure 9.8 indicates an example of an inverter operated under the condition of Tc=125C. It indicates
the effective current Io which can be outputted when the junction temperature Tj rises to the average junction
temperature of 150C (up to which the Mini DIP SPM operates safely).
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9.4 Heat Sink Design Guide
The selection of a heat sink is constrained by many factors including set space, actual operating power
dissipation, heat sink cost, flow condition around a heat sink, assembly location, etc. In this note, only some
of the constraints are analyzed to give some insights in heat sink selection from a practical application point
of view.
Heat Sink for Use in Washing Machines
The type of heat sink shown in Fig. 9.9 can be applied under natural convection conditions in washing
machine applications that have drive characteristics in which the power dissipated is alternatively high and
low over periods of hundreds of milli-seconds in the SPM.
a
b
d, g
c
f
e
Figure 9.9 A heat sink example for washing machines applications.
a = Fin thickness, b = Fin spacing, c = Fin height, d = Fin length,
e = Base-plate thickness, f = Base-plate width, g = Base-plate length
Figures 9.10 - 9.13 show the analysis results for the heat sink-to-ambient thermal resistance, Rha, in
designing the heat sink. This varies widely with the changes in fin spacing, fin/base-plate length and fin/baseplate width. It should be noted that the optimum fin spacing is approximately 4 or 5 mm with a base-plate
area of 7353 mm2, as shown in Fig. 9.10. Increasing the fin spacing results in a reduction of the total
number of fins, i.e., the total convection area. Reducing the fin spacing interferes with the airflow field
between the adjacent fins. This causes an increase in the thermal resistance when the fins are spaced below
and above 4mm and 5mm, respectively. An increase in fin thickness decreases the total number of fins and
the size of the heat sink, resulting in an increase in thermal resistance.
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Fin Thickness
3.6
a: 0.5mm
a: 1.0mm
a: 1.5mm
a: 2.0mm
Rha (℃/W)
3.2
2.8
2.4
2.0
3
4
5
6
7
8
Fin to Fin Spacing, b(mm)
Figure 9.10 Rha variation by change of the fin spacing.
(Constant: c=21mm, d=53mm, e=4mm, f=78mm, g=53mm)
Figures 9.11 and 9.12 show the results to see the effect of the base-plate length and width on thermal
resistance. From Fig. 9.11, we can see that the increase in the length to 150%, that is 79.5mm (53mm1.5),
reduces the resistance to 85% (2.3 C/W), and an increase of 200% (53mm2=106mm) reduces the
resistance to 78% (2.09 C/W). Figure 9.12 is the result of the variation in the base-plate width and it shows
that the increase in the width to 150% (78mm1.5=117mm) and 200% (78mm2=156mm) reduces the
resistance to 79% (2.144 C/W) and 70% (1.88 C/W), respectively. Therefore, increasing the width is
more effective reducing the thermal resistance, as compared with increasing the length.
Figure 9.13 shows the thermal resistance variation with a change in the fin height.
2.9
2.7
R ha
(℃/W)
2.5
2.3
2.1
1.9
1.7
1.5
50
70
90
110
130
150
170
Fin & Base plate length, d, g (mm)
Figure 9.11 Rha variation by change of the base-plate length.
(Content: a=1.5mm, b=5.45mm, c=21mm, e=4mm, f=78mm)
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2.9
2.7
R ha
(℃/W)
2.5
2.3
2.1
1.9
1.7
1.5
70
90
110
130
150
170
Base plate width, f(mm)
Figure 9.12 Rha variation by change of the base-plate width.
(Constant: a=1.5mm, b=5.45mm, c=21mm, d=53mm, e=4mm, g=53mm)
4.5
4.0
R ha
(℃/W)
3.5
3.0
2.5
2.0
1.5
10
15
20
25
30
Fin height, c (mm)
35
40
45
Figure 9.13 Rha variation by change of the fin height.
(Constant: a=1.5mm, b=5.45mm, d=53mm, e=4mm, f=78mm, g=53mm)
Heat Sink for Use in Air-Conditioners
Inverters for air-conditioner applications need continuous power dissipation in the SPM, which are
different from those used in washing machines. They generally use a heat sink with forced-convection using
a fan for the SPM.
Figure 9.14 shows the shape of a heat sink, which is generally used in air conditioning
systems. In this section, the airflow velocity effect on the thermal resistance is described based on using the
heat sink shown in Fig. 9. 14.
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Airflow direction
b
a
d
e
c
g
f
Figure 9.14 A heat sink example for air-conditioner applications.
(Constant: a= 2mm, b= 6mm, c= 30mm, d=140mm, e=7mm, f=76/100mm, g=160mm)
Figure 9.15 shows the airflow velocity effect on the resistance, Rha. Two kinds of heat sink base-plates
are used and the reference values of the thermal resistance are around 1.4 C/W and 1.6 C/W, respectively,
depending on the natural convection condition. We can see that the forced convection reduces the
resistance approximately three times. In this case the air velocity is about 2 m/sec, and it is an optimal and
cost-effective heat sink size. A fan having a velocity of 5 m/sec., reduces the resistance to 85% (0.25 C/W).
Figure 9.15 Rha variation by change of airflow velocity.
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10. Package
10.1 Heat Sink Mounting
The following precautions should be observed to maximize the effect of the heat sink and minimize
device stress, when mounting an SPM on a heat sink.
Heat Sink
Please follow the instructions of the manufacturer, when attaching a heat sink to an Mini DIP SPM. Be
careful not to apply excessive force to the device when attaching the heat sink.
Drill holes for screws in the heat sink exactly as specified. Smooth the surface by removing burrs and
protrusions of indentations. Refer to Table 10.1.
Heat-sink-equipped devices can become very hot when in operation. Do not touch, as you may sustain
a burn injury.
Silicon Grease
Apply silicon grease between the SPM and the heat sink to reduce the contact thermal resistance. Be
sure to apply the coating thinly and evenly, do not use too much. A uniform layer of silicon grease (100
~ 200um thickness) should be applied in this situation.
Screw Tightening Torque
Do not exceed the specified fastening torque. Over tightening the screws may cause package cracks
and bolts and AL heat-fin destruction. Tightening the screws beyond a certain torque can cause
saturation of the contact thermal resistance. The tightening torques in table 10.1 is recommended for
obtaining the proper contact thermal resistance and avoiding the application of excessive stress to the
device.
Avoid stress due to tightening on one side only. Figure 10.1 shows the recommended torque order for
mounting screws. Uneven mounting can cause the SPM DBC substrate to be damaged.
Table 10.1 Torque Rating
Limits
Item
Mounting Torque
DBC Flatness
Condition
Mounting Screw : M3
Recommended
(Note Fig. 10.1)
Unit
0.62 Nm
Min.
Typ
Max
0.51
0.62
1.00
Nm
0
-
+120
m
+50
m
-
g
Heatsink Flatness
-100
Weight
-
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Mini DIP (SPM3) Application Note (2012-07-09)
(+ )
(+ )
(+ )
Figure 10.1 Flatness measurement position
10.2 Handling Precaution
When using semiconductors, the incidence of thermal and/or mechanical stress to the devices due to
improper handling may result in significant deterioration of their electrical characteristics and/or reliability.
Transportation
Handle the device and packaging material with care. To avoid damage to the device, do not toss or
drop. During transport, ensure that the device is not subjected to mechanical vibration or shock. Avoid
getting devices wet. Moisture can also adversely affect the packaging (by nullifying the effect of the
antistatic agent). Place the devices in special conductive trays. When handling devices, hold the package
and avoid touching the leads, especially the gate terminal. Put package boxes in the correct direction.
Putting them upside down, leaning them or giving them uneven stress might cause the electrode terminals
to be deformed or the resin case to be damaged. Throwing or dropping the packaging boxes might cause
the devices to be damaged. Wetting the packaging boxes might cause the breakdown of devices when
operating. Pay attention not to wet them when transporting on a rainy or a snowy day.
Storage
1) Avoid locations where devices will be exposed to moisture or direct sunlight. (Be especially careful
during periods of rain or snow.)
2) Do not place the device cartons upside down. Stack the cartons atop one another in an uprighrt
position only. : Do not place cartons on their sides.
3) The storage area temperature should be maintained within a range of 5C to 35C, with humidity kept
within the range from 40% to 75%.
4) Do not store devices in the presence of harmful (especially corrosive) gases, or in dusty conditions.
5) Use storage areas where there is minimal temperature fluctuation. Rapid temperature changes can
cause moisture condensation on stored devices, resulting in lead oxidation or corrosion. As a result,
lead solderability will be degraded.
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6) When repacking devices, use antistatic containers. Unused devices should be stored no longer than
one month.
7) Do not allow external forces or loads to be applied to the devices while they are in storage.
Environment
1) When humidity in the working environment decreases, the human body and other insulators can
easily become charged with electrostatic electricity due to friction. Maintain the recommended
humidity of 40% to 60% in the work environment. Be aware of the risk of moisture absorption by the
products after unpacking from moisture-proof packaging.
2) Be sure that all equipment, jigs and tools in the working area are grounded to earth.
3) Place a conductive mat over the floor of the work area, or take other appropriate measures, so that
the floor surface is grounded to earth and is protected against electrostatic electricity.
4) Cover the workbench surface with a conductive mat, grounded to earth, to disperse electrostatic
electricity on the surface through resistive components. Workbench surfaces must not be
constructed of low-resistance metallic material that allows rapid static discharge when a charged
device touches it directly.
5) Ensure that work chairs are protected with an antistatic textile cover and are grounded to the floor
surface with a grounding chain.
6) Install antistatic mats on storage shelf surfaces.
7) For transport and temporary storage of devices, use containers that are made of antistatic materials
of materials that dissipate static electricity.
8) Make sure cart surfaces that come into contact with device packaging are made of materials that
will conduct static electricity, and are grounded to the floor surface with a grounding chain.
9) Operators must wear antistatic clothing and conductive shoes (or a leg or heel strap).
10) Operators must wear a wrist strap grounded to earth through a resistor of about 1M.
11) If the tweezers you use are likely to touch the device terminals, use an antistatic type and avoid
metallic tweezers. If a charged device touches such a low-resistance tool, a rapid discharge can
occur. When using vacuum tweezers, attach a conductive chucking pad at the tip and connect it to
a dedicated ground used expressly for antistatic purposes.
12) When storing device-mounted circuit boards, use a board container or bag that is protected against
static charge. Keep them separated from each other, and do not stack them directly on top of one
another, to prevent static charge/discharge which occurs due to friction.
13) Ensure that articles (such as clip boards) that are brought into static electricity control areas are
constructed of antistatic materials as far as possible.
14) In cases where the human body comes into direct contact with a device, be sure to wear finger
cots or gloves protected against static electricity.
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Electrical Shock
A device undergoing electrical measurement poses the danger of electrical shock. Do not touch the
device unless you are sure that the power to the measuring instrument is off.
Circuit Board Coating
When using devices in equipment requiring high reliability or in extreme environments (where moisture,
corrosive gas or dust is present), circuit boards can be coated for protection. However, before doing so,
you must carefully examine the possible effects of stress and contamination that may result. There are
many and varied types of coating resins whose selection is, in most cases, based on experience. However,
because device-mounted circuit boards are used in various ways, factors such as board size, board
thickness, and the effects that components have on one another, makes it practically impossible to predict
the thermal and mechanical stresses that semiconductor devices will be subjected to.
10.3 Marking Specifications
Figure 10.2 Marking layout (bottom side)
F SBB1 5 C
XXX
60C
Figure 10.3 Marking dimension of FSBB15CH60C
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1. F : FAIRCHILD LOGO
2. XXX : Last 3 digits of Lot No.
3. YWW : WORK WEEK CODE ("Y" refers to the below alphabet character table)
4. Hole Side Marking
- CP : FSBB15CH60C (Product Name)
- XXX : Last 3 digits of Lot No.
- YWW : WORK WEEK CODE ("Y" refers to the below alphabet character table)
Table 10.2 Work Week Code
Y
2000
2001
Alphabet
A
B
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C
2003
2004
2005
2006
2007
2008
2009
2010
D
E
F
G
H
J
K
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10.4 Packaging Specifications
Figure 10.4 Description of packaging process for SPM27-CC.
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Figure 10.5 Description of packaging process for SPM27-CC.
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Figure 10.6 Description of packaging process for SPM27-JA.
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DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS
HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF
THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE
UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION.
As used herein:
1.
2.
Life support devices or systems are devices or systems
A critical component is any component of a life support
which, (a) are intended for surgical implant into the body, or
device or system whose failure to perform can be
(b) support or sustain life, or (c) whose failure to perform
reasonably expected to cause the failure of the life support
when properly used in accordance with instructions for use
device or system, or to affect its safety or effectiveness.
provided in the labeling, can be reasonably expected to
result in significant injury to the user.
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