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2010 Fairchild Semiconductor Corporation 1 RD344_FNA41560 Rev. 0.0.1
Reference Design RD-344
Fairchild Motion-SPMFNA41560 Three-Shunt Design
The following reference design supports a design of FNA41560. It should be used in conjunction with
the FNA41560 datasheet as well as Fairchilds application notes (AN-9070, AN-9071, AN-9072) andtechnical support team. Please visit Fairchilds website at http://www.fairchildsemi.com.
Application Fairchild DeviceInput Voltage
RangeTypical Power
RatingTopology
Home Appliance
(Air-Conditioner)
FNA41560
MMSZ5252B
LMV324
300~400VDC 1500WThree Shunt Solution
(Single Ground)
Key Features
FNA41560
600V-15A 3-phase IGBT inverter bridge including control ICs for gate driving and protection
Easy PCB layout due to built-in bootstrap diode and independent VS pin
Divided negative DC-link terminals for inverter current-sensing applications
Single-grounded power supply due to built-in HVIC
Built-in NTC thermistor for over-temperature monitoring
Isolation rating of 2000Vrms/min.
MMSZ5252B Silicon planar power Zener diodes, DO-41 glass case
24V/1.0W rating Zener diode
For use in stabilizing and clipping circuits with high power rating
Standard Zener voltage tolerance: 5%
LMV324
General-purpose, low-voltage, rail-to-rail output amplifier
80A supply current per channel
1.2MHz GBP(Gain Bandwidth Product)
1.5V/s slew rate
Low offset voltage
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2010 Fairchild Semiconductor Corporation 2 RD344_FNA41560 Rev. 0.0.1
1.Schematics
Figure 1. Block Diagram of Air Conditioner
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2010 Fairchild Semiconductor Corporation 3 RD344_FNA41560 Rev. 0.0.1
R31 100
R21 100
C510uF/35V
C6104
C710uF/35V
C810uF/35V
C26220uF/35V
C24
102
R17 100
R20 100
C140.1uF 630V
R280.008 2W
5V line
R31
4.7K
C25
102
C17
102
C16
102C15
102
R16 100
R18 100
R19 100
5V line
15V line
(1) UH
P
N
W
V
U15V line
C32104
C31100uF/16V
C28333
R35 62
COM
VCC
IN(UL)
IN(VL)
IN(WL)
VFO
CSC
OUT(WL)
OUT(VL)
OUT(UL)
NW (9)
NV (8)
NU (7)
W (6)
V (5)
U (4)
P (3)
(23) VS(V)
(26) VB(U)
(19) IN(VH)
(22) VB(W)
(10) CSC
(11) VFO
(14) IN(UL)
(13) IN(VL)
(12) IN(WL)
(15) COM
UVS
UVB
OUT(UH)
UVS
WVS
OUT(WH)
COM
VCC
OUT(VH)
IN(UH) VVS
IN(VH)
(25) VS(U)
(24) VB(V)
(21) VS(W)
(20) IN(UH)
(18) V(WH)
(17) VCC(H)
VTH (1)
RTH (2)
VVS
VVB
WVS
WVB
IN(WH)
(16) VCC(L)
ZD1
MMSZ5252B
C20
102
C19
102
C18
102
R9 6.8K 1%
5V line
Motion-SPM FNA41560
J1
(2)VH(3) WH
(4) UL(5) VL(6) WL(7) FO
(8) VNTC
(9) VDD
(10) VCC
(11) GND
NTC
ZD2MMSZ5252B
C10104
ZD3MMSZ5252B
C9104
ZD4MMSZ5252B
C27104
R
4
5V line
1
7
8
14
11
3
2
5
6
10
9
12
13
U1LMV324
R320.008 2W
R330.008 2W
R340.0082W
J2
(1) VIU
(2) VIV
(3) VIW
5V
R6 39K 1%
C4 101
R14 39K 1%
C13101
R27 39K 1%
C23 101
R407.87K 1%
C30 510
R1, R7, R8,
R15, R22, R29
: 78.7K 1%
C3, C12, C22
: 101
R1
R7
C3
R8
R15
C12
R29
C22
R22
R3 1.8K 1%
R51.8K 1%
R2 1.0K 1%
R4 1.0K 1%
R111.8K 1%
R131.8K 1%
R101.0K 1%
R121.0K 1%
C2 101
C11 101
R241.8K 1%
R261.8K 1%
R231.0K 1%
R251.0K 1%
C21 101
R371.8K 1%
R39 1.8K 1%
R361.0K 1%
R381.0K 1%
C29101
C33 101
R41 8.2K 1%
Figure 2. Reference Design for 3-Phase Inverter
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2010 Fairchild Semiconductor Corporation 4 RD344_FNA41560 Rev. 0.0.1
2.Key Parameter Design
2.1. Selection of Bootstrap Capacitance (CBS)
The bootstrap capacitor can be calculated by:
BS
LeakBS
V
tIC
=
(1)
where:
t = maximum on pulse width of high-side IGBT;
VBS = the allowable discharge voltage of the CBS (voltage ripple); and
ILeak= maximum discharge current of the CBS.
Normally, ILeakconsist of the following items:
- Gate charge for turning the high-side IGBT on
- Quiescent current to the high-side circuit in the HVIC- Level-shift charge required by level-shifters in HVIC
- Leakage current in the bootstrap diode
- CBScapacitor leakage current (ignored for non-electrolytic capacitors)
- Bootstrap diode reverse recovery charge.
Practically, 2mA of ILeakis recommended for Mini DIP SPM family in Motion-SPM
products (IPBS(operating VBSsupply current) value in datasheet) .
Calculation Examples of CBS
ILeak= circuit current (IPBS) = 2mA (recommended value)VBS = discharged voltage = 0.1V (recommended value)
t = maximum on pulsewidth of high-side IGBT = 2ms (depends on system)
6
min_ 100.41.0
2.02 =
=
=
V
msmA
V
tIC
BS
LeakBS
(2)
More than 2~3times 8FStandard nominal capacitance 10F.
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2010 Fairchild Semiconductor Corporation 5 RD344_FNA41560 Rev. 0.0.1
2.2. Design of Current-Sensing Circuit
Figure 3. General Circuit for Current Sensing
Figure 4. Typical Low-Side Current-Sensing Circuit
FNA41560 has a divided negative DC-link terminal (NU, NV, NW) for current sensing to
simplify current-sensing circuit design. Figure 3and Figure 4 show the typical three-shunt
current-sense circuit using the FNA41560 in Motion-SPM.
The value of application circuit is calculated by the following equations.
In Figure 5, the output voltage of op-amp (VOUT) can be calculated by:
)()(65
5
42
7min,min,
RR
RV
RR
RVV refShuntout
++
+=
(3)
)()(65
5
42
7max,max,
RR
R
VRR
R
VV refShuntout +++= (4)
According to Equation 3, the voltage between shunt resistor (VShunt) can be calculated by:
7
42
65
5maxmax, ]
)([
R
RR
RR
RVVV refoutShunt
+
+=
(5)
7
42
65
5minmin, ]
)([
R
RR
RR
RVVV refoutShunt
+
+=
(6)
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2010 Fairchild Semiconductor Corporation 6 RD344_FNA41560 Rev. 0.0.1
2.3. Calculation Examples for Current-Sensing Circuitry
Calculation Conditions
DUT: FNA41560
Op-Amp: LMV324
Resistance of shunt resistor: 8m, 1% tolerance, KOA
SC trip current: 22.5A (1.5 x IC (rated current))
Input voltage range of ADC of MCU: 0~+5V
Components value: refer to Figure 5 and Figure 6
Figure 5. Application Circuit of Current Sensing (VCC=5.0V, Voltage Gain=13.9)
Figure 6. Application Circuit of Current Sensing (VCC=3.3V, Voltage Gain=9.1)
VCC, Vref=5.0[V]Voltage gain=13.9Bandwidth = 86[kHz]
VCC, Vref=3.3VVoltage gain=9.2Bandwidth = 130[kHz]
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2010 Fairchild Semiconductor Corporation 7 RD344_FNA41560 Rev. 0.0.1
Figure 7. VADC (Input Voltage of AD Converter of MCU) vs. VShunt (Voltage of Shunt Resistor) in CurrentFeedback Circuitry (Figure 5, Figure 6)
According to calculation conditions, Figure 5, and Equations 5 and 6, the voltage
between shunt resistor (VShunt,min, VShunt,max) can be calculated by:
Vk
k
kk
kVV
R
RR
RR
RVVV refoutShunt 179.0
39
8.2]
7.787.78
7.7850[]
)([
7
42
65
5minmin, =
+
=
+
+=
Vk
k
kk
kVV
R
RR
RR
RVVV refoutShunt 179.0
39
8.2]
7.787.78
7.7855[]
)([
7
42
65
5maxmax, =
+
=
+
+=
According to Equation 3 and 4, the voltage of op-amp output can be calculated by:
Vkk
kVk
kVRR
RVRR
RVV refShuntout 0)7.787.78
7.785()8.2
39179.0()()(65
5
42
7min,min, =
+
+
=
++
+=
Vkk
kV
k
kV
RR
RV
RR
RVV refShuntout 0.5)
7.787.78
7.785()
8.2
39179.0()()(
65
5
42
7max,max, =
+
+
=
++
+=
For low control voltage systems, such as VCC=3.3V, the same consideration can be
performed on the circuit shown in Figure 6. The circuit in Figure 6 has a same
performance as the circuit in Figure 5. Figure 7 shows VShuntvs. VADCaccording to VCC
variation (3.3V, 5.0V) and gain of op-amp.
2.4. Components Calculation Examples for SCP
Calculation Conditions DUT: FNA41560
Op-Amp: LMV324
Resistance of shunt resistor: 8m, 1% tolerance, KOA
SC trip current: 22.5A (1.5 x IC (rated current), can be changed by designer)
SC trip reference voltage: VSC(min)=0.45V, VSC(typ)=0.50V, VSC(max)=0.55V
Components value: refer to Figure 8
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2010 Fairchild Semiconductor Corporation 8 RD344_FNA41560 Rev. 0.0.1
Vkk
kVV
RR
RV shuntshuntout 505.0179.0)
8.10.1
87.7()()(
98
13=
+
=
+=
+
Figure 8. Application Circuit of SCP(Short-Circuit Current Protection)
2.5. Power Rating of Shunt Resistor Calculation Example
Calculation Conditions
Vendor of shunt resistor: KOA (TLR3AW 8m)
Maximum load current of inverter (Irms): 10Arms
Shunt resistor value at TC=25oC (RSHUNT): 8.0m
Derating ratio of shunt resistor at TSHUNT=100oC: 65%
Safety margin: 20%
Figure 9. Derating Curve of Shunt Resistor (KOA, TLA Series)
PSHUNT (I2rmsx RSHUNTx Margin) / Derating ratio)=(10
2x 0.008x 1.2) / 0.65=1.48W
(Therefore, the proper power rating of shunt resistor is over 2.0W)
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2010 Fairchild Semiconductor Corporation 9 RD344_FNA41560 Rev. 0.0.1
2.6. Temperature-Monitoring Circuit
-20 -10 0 10 20 30 40 50 60 70 80 90 100 110 1200
50
100
150
200
250
300
350
400
450
500
550
600
MINTYPMAX
R-T Curve
Resistance[k]
Temperature TTH
[]
Figure 10. R-T Curve of NTC thermistor in Mini DIP SPM Package
Figure 10 is R-T curve of the integrated NTC thermistor in Mini DIP SPM package.
For R-T table of NTC thermistor, refer to application note Mini DIP SPM(AN-9070).
Motion-SPMTMMCU
VDD
VTH
RTHADC Port
RTH
NTC
Figure 11. Temperature-Sensing Circuit by NTC Thermistor
Figure 11 is example of a temperature-sensing circuit by NTC thermistor. In this
reference design, RTHis 6.8kand Figure 12 is the V-T curve at RTH=6.8k,
VCC=3.3V, and VCC= 5.0V.
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2010 Fairchild Semiconductor Corporation 10 RD344_FNA41560 Rev. 0.0.1
20 30 40 50 60 70 80 90 100 110 1200
1
2
3
4
5
VDD
=3.3V
VDD
=5.0V
VOUT(min)
VOUT(typ)
VOUT(max)
V-T Curve at VDD
=5.0, 3.3V, RTH
=6.8kohm
Ou
tputVoltage
ofR
TH[
V]
Temperature TThermistor
[oC]
Figure 12. V-T Curve of Temperature-Sensing Circuit in Reference Design
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2010 Fairchild Semiconductor Corporation 11 RD344_FNA41560 Rev. 0.0.1
2.7. Print Circuit Board(PCB) Layout Guidance
Figure 13. PCB Layout Guidance
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2010 Fairchild Semiconductor Corporation 12 RD344_FNA41560 Rev. 0.0.1
3.Related Resources
FNA41560 Smart Power Module Motion-SPM
AN-9070 Smart Power Module Motion-SPM
in Mini DIP SPMUser Guide
AN-9071 Smart Power Module Motion-SPM in Mini DIP SPMThermal Performance Information
AN-9072-Smart Power Module Motion-SPMin Mini DIP SPMMounting Guidance
http://www.fairchildsemi.com/referencedesign/
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