STK534U3xx Series Application Note

STK534U3xx series
Application Note
www.onsemi.com
1. Product synopsis
This application handbook is intended to provide practical guidelines for the STK534U3xx series use.
The STK534U3xx series is Intelligent Power Module (IPM) based upon ONs Insulated Metal Substrate
Technology (IMST) for 3-phase motor drives which contain the main power circuitry and the supporting
control circuitry. The key functions are outlined below:







Highly integrated device containing all High Voltage (HV) control from HV-DC to 3-phase outputs in
a single small SIP module.
Output stage uses IGBT/FRD technology and implements Under Voltage Protection (UVP) and Over
Current Protection (OCP) with a Fault Detection output flag. Internal Boost diodes are provided for
high side gate boost drive.
Option of a combined or individual shunt resistor per phase for OCP.
Externally accessible embedded thermistor for substrate temperature measurement.
All control inputs and status outputs are at low voltage levels directly compatible with microcontrollers.
Single control power supply due to internal bootstrap circuit for high side pre-driver circuit.
Mounting points are available on SIP package
A simplified block diagram of a motor control system is shown in Figure 1.
Intelligent Power Module
Figure 1. Motor Control System Block Diagram
Semiconductor Components Industries, LLC, 2014
Nov, 2014
1/21
Rev.2
STK534U3xx series Application Note
2. Product description
Table1. gives an overview of the available devices, for a detailed description of the packages refer to
Chapter 6.
Device
Feature
Package
Voltage (VCEmax.)
Current (Ic)
Peak current (Ic)
Isolation voltage
Shunt resistance
STK534U342C-E
STK534U362C-E
triple shunts
SIP05 – Vertical pins
600V
5A
10A
10A
20A
2000V
external
Horizontal type models: STK534U3xxA-E series are available for pin forming option.
Table 1. Device Overview
VB3( 1)
W,VS3( 2)
VB2( 5)
V,VS2( 6)
VB1( 9)
U,VS1(10)
V+
P (13)
DB
DB
DB
U.V.
U.V.
U.V.
U- (17)
V- (19)
W- (21)
Level
Level
Level
Shifter
Shifter
Shifter
HIN1(20)
HIN2(22)
HIN3(23)
Logic
Logic
Logic
LIN1(24)
LIN2(25)
LIN3(26)
Thermistor
TH(27)
ITRIP(16)
Shutdown
VDD(28)
VSS(29)
Enable/Disable
Under voltage
+
Detect
-
S
Timer
Q
R
Vref
Latch time about 2ms
FLTEN(18)
Figure 2. STK534U3xx series equivalent circuits
The high side drive is used with a bootstrap circuit to generate the higher voltage needed for gate drive.
The Boost diodes are internal to the part and sourced from VDD (15V). There is an internal level shift circuit for the high side drive signals allowing all control signals to be driven directly from Vss levels common
with the control circuit such as the microcontroller without requiring external level shift such as opto isolators.
2/21
STK534U3xx series Application Note
3. Performance test guidelines
The following Chapter gives performance test method shown in Figures 3 to 7.
3.1. Switching time definition and performance test method
trr
10%
90%
VCE
90%
10%
Io
td(ON)
10%
td(OFF)
tr
tf
tOFF
tON
IN
Figure 3. Switching time definition
Ex) Lower side U phase measurement
+
VB1
VD1=15V
VS1,U
VB2
VD2=15V
VS2,V
VS1,U
Vcc
VB3
CS
VD3=15V
VS3,W
VDD
Io
VD4=15V
Input signal
U-
LIN1
VSS
ITRIP
Figure 4. Evaluation circuit (Inductive load)
IPM
Ho
HIN1,2,3
CS
VCC
Driver
U,V,W
LIN1,2,3
Lo
Input signal
Io
Input signal
Io
Figure 5. Switching loss circuit
3/21
STK534U3xx series Application Note
IPM
Ho
HIN1,2,3
CS
VCC
Driver
U,V,W
LIN1,2,3
Lo
Input signal
Io
Input signal
Io
Figure 6. R.B.SOA circuit
IPM
Ho
HIN1,2,3
CS
VCC
Driver
U,V,W
LIN1,2,3
Lo
Input signal
Io
Input signal
Io
Figure 7. S.C.SOA circuit
4/21
STK534U3xx series Application Note
3.2. Thermistor Characteristics
The thermistor is built-in between TH and VSS. This is used to sense internal module temperature.
Its characteristic is outlined below.
Parameter
Resistance
Resistance
B-Constant(25-50°C)
Symbol
R25
Condition
Tc=25°C
R100
Tc=100°C
Min
97
B
Temperature Range
Typ.
100
Max
103
Unit
kΩ
5.07
5.38
5.71
kΩ
4208
4250
4293
K
°C
-40
+125
Table 2. NTC Thermistor value
R25 is the value of the integrated NTC thermistor at Tc=25 °C. The resistance value is 100kΩ±3%
and the value of the B-Constant (25-50°C) is 4250K±1%. The temperature depended value is
calculated as shown in the formula.
𝐑(𝐭) = 𝐑 𝟐𝟓 ×
𝟏 𝟏
𝐁(𝐓−𝟐𝟗𝟖)
𝐞
The resulting in the NTC values over temperatures
Thermistor resistance - Case temperature
Thermistor resistance [kΩ]
10000
min
1000
typ
max
100
10
1
-50
0
50
100
150
Case temperature [˚C]
Figure 8. typical NTC value over temperature
4. Protective functions and Operation Sequence
This chapter describes the protection features.
 over current protection
 short circuit protection
 under Voltage Lockout (UVLO) protection
 cross conduction prevention
5/21
STK534U3xx series Application Note
4.1. Over current protection
In difference to the internal single shunt series modules the STK534Uxxx series modules utilize an external
shunt resistor for the OCP functionality. As shown in Figure 9 the emitters of all three lower side IGBTs
brought out to module pins. An external “over current protection circuitry” consisting of the shunt resistor and an RC filter network define the trip level.
IPM
V+(P)
VSS
ITRIP
Driver
U
V
W
VShunt
Over current
protection circuit
UVW-
Figure 9. Over-current protection circuit setting
The OCP function is implemented by comparing the voltage on the Itrip input to an internal reference of
0.49V (typ). In case the voltage on this terminal i.e. across the shunt resistor exceeds the trip level an OCP
fault is triggered.
Note:
The current value of the OCP needs to be set by correctly sizing the external shunt resistor
to less than 2x of the modules rated current.
In case of an OCP event all internal gate drive signal for the IGBTs of all three phases become inactive and
the FLT/EN fault signal output is activated (low).
Collector Current Ic (A)
An RC filter is used on the Itrip input to prevent an erroneous OCP detection due to normal switching
noise and/or recovery diode current. The time constant of that RC filter should be set to a value between
1.5μ to 2μs. In any case the time constant must be shorter than the IGBTs short current safe operating
area (SCSOA). Please refer to Data Sheet for SCSOA. The resulting OCP level due to the filter time constant
is shown in Figure 10.
Over-current protective level
Collector Current
Waveform
Input pulse width tw (usec.)
Figure 10. filter time constant
6/21
STK534U3xx series Application Note
For optimal performance all traces around the shunt resistor need to be kept as short as possible
Figure 11. shows the sequence of events in case of an OCP event.
HIN/LIN
Protection state
Set
Reset
HVG/LVG
Normal operation
Over current
Over current
detection
IGBT turn off
Output Current Ic (A)
Over current reference voltage
Voltage of
Shunt resistor
RC circuit time constant
Fault output
Fault output
Figure 11. Over current protection Timing chart
4.2. Under Voltage Lockout Protection
The UVLO protection is designed to prevent unexpected operating behavior as described in Table 3. Both
High-side and Low-side have UV protecting function. However the fault signal output only corresponds to
the Low-side UVLO Protection. During the UVLO state the fault output is continuously driven (low).
VDD Voltage (typ. Value)
Operation behavior
< 12.5V
As the voltage is lower than the UVLO threshold the control
circuit is not fully turned on.
A perfect functionality cannot be guaranteed.
12.5 V – 13.5 V
IGBTs can work, however conduction and switching losses
increase due to low voltage gate signal.
13.5 V – 16.5 V
Recommended conditions
16.5 V – 20.0 V
IGBTs can work. Switching speed is faster and saturation
current higher, increasing short-circuit broken risk.
> 20.0 V
Control circuit is destroyed. Absolute max. rating is 20 V.
Table 3.
Module operation according to control supply voltage
7/21
STK534U3xx series Application Note
The sequence of events in case of a low side UVLO event (IGBTs turned off and active fault output) is
shown in Figure 12. Figure 13 shows the same for a high side UVLO (IGBTs turned off and no fault output).
LIN
Protection state
Reset
Set
Reset
Control supply voltage VD
Under voltage reset
Under voltage trip
Normal operation
Output Current Ic (A)
After the voltage level reaches UV reset, the circuits start to
operate when next input is applied .
IGBT turn off
Fault output
Fault output
Figure 12. Low side UVLO timing chart
Figure 13. High side UVLO timing chart
8/21
STK534U3xx series Application Note
4.3. Cross conduction prevention
The STK534U3xx series module implement a cross conduction prevention logic at the pre-driver to avoid
simultaneous drive of the low- and high-side IGBTs as shown in Figure 14.
Figure 14. Cross Input Conduction Prevention
In case of both high and low side drive inputs are active (high) the logic prevents both gates from being
driven – a corresponding timing diagram can be found in Figure 15 below.
HIN
LIN
Shoot-Through
Prevention
HVG
Normal operation
Normal operation
LVG
VDD
Fault output
Keeping high level output ( No Fault output )
Figure 15. cross conduction prevention timing diagram
Even so cross conduction on the IGBTs due to incorrect external driving signals is prevented by the circuitry the driving signals (HIN and LIN) need to include a “dead time”. This period where both inputs are
inactive between either one becoming active is required due to the internal delays within the IGBTs. Figure 16 shows the delay from the HIN-input via the internal HVG to high side IGBT, the similar path for the
low side and the resulting minimum dead time which is equal to the potential shoot through period:
9/21
STK534U3xx series Application Note
HIN
LIN
tON
High Side IGBT
tOFF
Low Side IGBT
Shoot-Trough Period
Dead time = tOFF-tON
Figure 16. Shoot Trough Period
5. PCB design and mounting guidelines
This chapter provides guidelines for an optimized design and PCB layout as well as module mounting
recommendations to appropriately handle and assemble the IPM.
5.1. Application (schematic) design
The following figures 17 gives an overview of the external circuitry’s functionality when designing with the
STK534U3xx series module.
Figure 17. STK534U3xx series application circuit
10/21
STK534U3xx series Application Note
Figure 18. PCB design reference
5.2. Pin by pin design and usage notes
This section provides pin by pin PCB layout recommendations and usage notes. For a complete list of
module pins refer to the datasheet or Chapter 6.
P, U-, V-, W-
These pins are connected with the main DC power supply. The applied voltage is up to
the Vcc level. Overvoltage on these pins could be generated by voltage spikes during
switching at the floating inductance of the wiring. To avoid this behavior the wire traces need to be as short as possible to reduce the floating inductance. In addition a
snubber capacitor needs to be placed as close as possible to these pins to stabilize the
voltage and absorb voltage surges.
U, V, W
These terminals are the output pins for connecting the 3-phase motor. They share the
same GND potential with each of the high side control power supplies. Therefore they
are also used to connect the GND of the bootstrap capacitors. These bootstrap capacitors should be placed as close to the module as possible.
VDD, VSS
These pins connect with the circuitry of the internal protection and pre-drivers for the
low-side power elements and also with the control power supply of the logic circuitry.
Voltage to input these terminals is monitored by the under voltage protection circuit.
The VSS terminal is the reference voltage for the control inputs signals.
VB1, VB2,
VB3
The VBx pins are internally connected to the positive supply of the high-side drivers.
The supply needs to be floating and electrically isolated. The boot-strap circuit shown
in Figure 19 forms this power supply individually for every phase. Due to integrated
boot resistor and diode (RB & DB) only an external boot capacitor (CB) is required.
11/21
STK534U3xx series Application Note
CB is charged when the following two conditions are met.
① Low-side signal is input
② Motor terminal voltage is low level
The capacitor is discharged while the high-side driver is activated.
Thus CB needs to be selected taking the maximum on time of the high side and the
switching frequency into account.
CB
DB
Driver
RB
VDD
Driver
Figure 19. Boot Strap Circuit
The voltages on the high side drivers are individually monitored by the under voltage
protection circuit. In case an UVP event is detected on a phase its operation is stopped.
Typically a CB value of less or equal 47uF (±20%) is used. In case the CB value needs to
be higher an external resistor (of apx. 20Ω or less) should be used in series with the
capacitor to avoid high currents which can cause malfunction of the IPM.
HIN1, LIN1,
HIN2, LIN2,
HIN3, LIN3
These pins are the control inputs for the power stages. The inputs on HIN1/HIN2/HIN3
control the high-side transistors of U/V/W, and the inputs on LIN1/LIN2/LIN3 control
the low-side transistors of U/V/W respectively. The input are active high and the input
thresholds VIH and VIL are 5V compatible to allow direct control with a microcontroller
system
Simultaneous activation of both low and high side is prevented internally to avoid
shoot through at the power stage. However, due to IGBT switching delays the control
signals must include a dead-time.
The equivalent input stage circuit is shown in Figure 20.
IN
33k
VSS
Figure 20. Internal Input Circuit
12/21
STK534U3xx series Application Note
For fail safe operation the control inputs are internally tied to VSS via a 33kΩ (typ) resistor. To avoid switching captured by external wiring to influence the module behavior
an additional external low-ohmic pull-down resistor with a value of 2.2kΩ-3.3kΩ should
be used.
The output might not respond when the width of the input pulse is less than 1µs (both
ON and OFF).
FLTEN
The FLTEN pin is an active low input and open-drain output. It is used to indicate an internal fault condition of the module and also can be used to disable the module operation. The I/O structure is shown in Figure 21.
The internal sink current IoSD during an active fault is nominal 2mA @ 0.1V. Depending
on the interface supply voltage the external pull-up resistor (RP) needs to be selected
to set the low voltage below the VIL trip level.
For the commonly used supplies VP:
VP = 15V -> RP >= 20kΩ
VP = 5V -> RP>= 6.8kΩ
VP
VDD
RP
FLTEN
VSS
Figure 21. Fault Connection
For a detailed description of the fault operation refer to Chapter 4.
Note: The Fault signal does automatically re-started after the causing protection event
end AND after the fault timeout of 2ms. Therefore the input needs to be driven low
externally activated as soon as a fault is detected.
TH
An internal thermistor to sense the substrate temperature is connected between VSS
and the TH pins. In conjunction with an external pull-up resistor Rth a module temperature monitor can be build.
Note:
with this mimic only the substrate temperature can be monitored.
13/21
STK534U3xx series Application Note
5.3. Heat sink mounting and torque
If a heat sink is used, insufficiently secure or inappropriate mounting can lead to a failure of the heat sink
to dissipate heat adequately. This can lead to an inability of the device to provide its inherent performance, a serious reduction in reliability, or even destruction, burst and burn of the device due to overheating.
The following general points should be observed when mounting IPM on a heat sink:
1. Verify the following points related to the heat sink:
- There must be no burrs on aluminum or copper heat sinks.
- Screw holes must be countersunk.
- There must be no unevenness in the heat sink surface that contacts IPM.
- There must be no contamination on the heat sink surface that contacts IPM.
2. Highly thermal conductive silicone grease needs to be applied to the whole back
(aluminum substrate side) uniformly, and mount IPM on a heat sink. Upon
re-mounting apply silicone grease(100um to 200um) again uniformly.
3. For an intimate contact between the IPM and the heat sink, the mounting screws
should be tightened gradually and sequentially while a left/right balance in pressure
is maintained. Either a bind head screw or a truss head screw is recommended.
Please do not use tapping screw. We recommend using a flat washer in order to
prevent slack. The standard heat sink mounting condition of STK534U3xx series is as
follows.
Table 4. heat sink mounting
14/21
STK534U3xx series Application Note
Steps to mount an IPM on a heat sink
1st: Temporarily tighten maintaining a left/right balance.
2nd : Finally tighten maintaining a left/right balance.
5.4. Mounting and PCB considerations
In designs in which the printed circuit board and the heat sink are mounted to the chassis independently,
use a mechanical design which avoids a gap between IPM and the heat sink, or which avoids stress to the
lead frame of IPM by an assembly that a moving IPM is forcibly fixed to the heat sink with a screw.
IPM
Figure 22. Fix to Heat Sink
Maintain a separation distance of at least 1.5 mm between the IPM case and the printed circuit board. In
particular, avoid mounting techniques in which the IPM substrate or case directly contacts the printed
circuit board.
15/21
STK534U3xx series Application Note
Do not mount IPM with a tilted orientation. This can result in stress being applied to the lead frame and
IPM substrate could short out tracks on the printed circuit board. Always mount the IPM vertically. If
stress is given by compulsory correction of a lead frame after the mounting, a lead frame may drop out.
Be careful of this point.
IPM
When designing the PCB layout take care that the bent part portion of the lead frame pins does not
short-circuit to VIA holes or tracks on the PCB.
IPM
Since the use of sockets to mount IPM can result in poor contact with IPM leads, we strongly recommend
making direct connections to PCB.
IPMs are flame retardant. However, under certain conditions, it may burn, and poisonous gas may be
generated or it may explode. Therefore, the mounting structure of the IPM should also be flame retardant.
Mounting on a Printed Circuit Board
1. Align the lead frame with the holes in the printed circuit board and do not use excessive force
when inserting the pins into the printed circuit board. To avoid bending the lead frames, do not try
to force pins into the printed circuit board unreasonably.
2. Do not insert IPM into printed circuit board with an incorrect orientation, i.e. be sure to prevent
reverse insertion. IPM may be destroyed, exploded, burned or suffer a reduction in their operating
lifetime by this mistake.
3. Do not bend the lead frame.
5.5. Cleaning
IPM has a structure that is unable to withstand cleaning. As a basic policy, do not clean independent IPM
or printed circuit boards on which an IPM is mounted.
16/21
STK534U3xx series Application Note
6. Package Outline
STK534U3xx series is SIP05 package. (Single-inline-package)
Every second pin is bent forward to form two rows on the PCB see Figure 23.
6.1. Package outline and dimension
STK534U3xxC-E (Vertical type)
missing pin: 3,4,7,8,11,12,14,15
note1: Mirror surface for No.1 pin identification
note2: Model number
note3: Lot code
* The form of a character in this drawing differs
from that of IPM.
Figure 23. Package Outline
17/21
STK534U3xx series Application Note
6.2. Pin Out Description
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Name
VB3
W,VS3
NA
NA
VB2
V,VS2
NA
NA
VB1
U,VS1
NA
NA
P
NA
NA
ITRIP
UFLTEN
VHIN1
WHIN2
HIN3
LIN1
LIN2
LIN3
TH
VDD
VSS
Description
High Side Floating Supply Voltage 3
Output 3 - High Side Floating Supply Offset Voltage
none
none
High Side Floating Supply voltage 2
Output 2 - High Side Floating Supply Offset Voltage
none
none
High Side Floating Supply voltage 1
Output 1 - High Side Floating Supply Offset Voltage
none
none
Positive Bus Input Voltage
none
none
Shut-down Pin
Low Side Emitter Connection - Phase 1
Enable input / Fault output
Low Side Emitter Connection - Phase 2
Logic Input High Side Gate Driver - Phase 1
Low Side Emitter Connection - Phase 3
Logic Input High Side Gate Driver - Phase 2
Logic Input High Side Gate Driver - Phase 3
Logic Input Low Side Gate Driver - Phase 1
Logic Input Low Side Gate Driver - Phase 2
Logic Input Low Side Gate Driver - Phase 3
Temperature Monitor
+15V Control Power Supply
Negative Control Power Supply
18/21
STK534U3xx series Application Note
7. Demo Board
The demo board consists of the minimum required components such as snubber capacitor and bootstrap
circuit elements of STK534U3xx series.
Figure 24. Evaluation board schematic
Length : 96mm
Side : 128mm
Thickness : 1.6mm
Rigid double-sided substrate
Material : FR-4
Copper foil thickness : 70um
Both sides resist coating
Surface
Back side
Figure 25. Evaluation board PCB layout (TOP view)
19/21
STK534U3xx series Application Note
IPM
W
Shunt resistor
V
VSS
U
Vext
VDD
U-
1kΩ
V-
20kΩ
W-
20kΩ
TH
ITRIP
FLTEN
LIN3
LIN2
LIN1
HIN3
HIN2
HIN1
-
100Ω
100pF
3.3kΩ
Vext
VSS
VDD
UVWTH
ITRIP
FLTEN
LIN3
LIN2
LIN1
HIN3
HIN2
HIN1
VSS
NC
NC
NC
NC
+
Evaluation Board
* To enable over-current protection function, it is necessary to
connect shunt resistors. Please short the terminals of shunt
resistor when you do not use this function.
Figure 26. Description of each pin
IPM
W
Motor
Shunt resistor
V
VSS
U
Logic
Vext
VDD
U-
1kΩ
V-
20kΩ
W-
20kΩ
TH
ITRIP
FLTEN
LIN3
LIN2
LIN1
HIN3
HIN2
HIN1
100Ω
100pF
3.3kΩ
DC 15V
Vext
VSS
VDD
UVWTH
ITRIP
FLTEN
LIN3
LIN2
LIN1
HIN3
HIN2
HIN1
VSS
NC
NC
NC
NC
-
+
DC
power
supply
Evaluation Board
Figure 27. Evaluation board instructions
20/21
STK534U3xx series Application Note
Operation procedure
Step1: Please connect IPM, each power supply, logic parts and the motor
to the evaluation board, and confirm that each power supply is OFF at this time.
Step2: Please impress the power supply of DC15V.
Step3: Please perform a voltage setup according to specifications, and impress the power supply
between the "+" and the "-" terminal.
Step4: By inputting signal to the logic part, IPM control is started.
(Therefore, please set electric charge to the boot-strap capacitor of upper side to turn on
lower side IGBT before running.)
* When turning off the power supply part and the logic part, please carry out in the reverse order
to above steps.
ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC) or its subsidiariesin the United States
and/or other countries. SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of
SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf . SCILLC reserves the right to make changes without
further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitabilityof its products for any particular purpose,
nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including
without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can
and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each
customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are
not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applicationsintended to support or
sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers,
employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of,
directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was
negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all
applicable copyright laws and is not for resale in any manner.
21/21