0.4 Amp Output Current IGBT Gate Drive Optocoupler Technical Data HCPL-J314 Features • 0.4 A Minimum Peak Output Current • High Speed Response: 0.7 µs Max. Propagation Delay over Temp. Range • Ultra High CMR: Min. 10 kV/µs at V CM = 1.5 kV • Bootstrappable Supply Current: Max. 3 mA • Wide Operating Temp. Range: -40° C to 100° C • Wide V CC Operating Range: 10 V to 30 V over Temp. Range • Available in DIP8 (Single) and SO16 (Dual) Package • Safety Approvals: UL Recognized, 3750 V rms for 1 Minute. CSA Approval IEC/EN/DIN EN 60747-5-2 Approval. VIORM=891 V peak Applications • Isolated IGBT/Power MOSFET Gate Drive • AC and Brushless DC Motor Drives • Inverters for Appliances • Industrial Inverters • Switch Mode Power Supplies (SMPS) • Uninterruptable Power Supplies (UPS) Description The HCPL-J314 family of devices consists of an AlGaAs LED optically coupled to an integrated circuit with a power output stage. These optocouplers are ideally suited for driving power IGBTs and MOSFETs used in motor control inverter applications. The high operating voltage range of the output stage provides the drive voltages required by gate controlled devices. The voltage and current supplied by this optocoupler makes it ideally suited for directly driving small or medium power IGBTs. For IGBTs with higher ratings the HCPL-3150(0.5A) or HCPL-3120 (2.0A) optocouplers can be used. Functional Diagram A 0.1 µF bypass capacitor must be connected between pins V CC and V EE . CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by ESD. Truth Table LED V O OFF LOW ON HIGH 1 3 SHIELD 2 4 8 6 7 5 N/C CATHODE ANODE N/C V CC V O V O V EE HCPL-J314
17
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0.4 Amp Output CurrentIGBT Gate Drive Optocoupler
Technical Data
HCPL-J314
Features• 0.4 A Minimum Peak
Output Current
• High Speed Response:
0.7 µs Max. Propagation
Delay over Temp. Range
• Ultra High CMR: Min.
10 kV/µs at VCM = 1.5 kV
• Bootstrappable Supply
Current: Max. 3 mA
• Wide Operating Temp.
Range: -40°C to 100°C• Wide VCC Operating Range:
10 V to 30 V over Temp.
Range
• Available in DIP8 (Single)
and SO16 (Dual) Package
• Safety Approvals: UL
Recognized, 3750 Vrms for
1 Minute. CSA Approval
IEC/EN/DIN EN 60747-5-2
Approval. VIORM=891 Vpeak
Applications• Isolated IGBT/Power
MOSFET Gate Drive
• AC and Brushless DC Motor
Drives
• Inverters for Appliances
• Industrial Inverters
• Switch Mode Power
Supplies (SMPS)
• Uninterruptable Power
Supplies (UPS)
DescriptionThe HCPL-J314 family of devicesconsists of an AlGaAs LEDoptically coupled to an integratedcircuit with a power output stage.These optocouplers are ideallysuited for driving power IGBTsand MOSFETs used in motorcontrol inverter applications. Thehigh operating voltage range ofthe output stage provides thedrive voltages required by gatecontrolled devices. The voltageand current supplied by thisoptocoupler makes it ideallysuited for directly driving smallor medium power IGBTs. ForIGBTs with higher ratings theHCPL-3150(0.5A) or HCPL-3120(2.0A) optocouplers can be used.
Functional Diagram
A 0.1 µF bypass capacitor must be connected between pins VCC and VEE.
CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to preventdamage and/or degradation which may be induced by ESD.
Truth Table
LED VO
OFF LOW
ON HIGH
1
3
SHIELD
2
4
8
6
7
5
N/C
CATHODE
ANODE
N/C
VCC
VO
VO
VEE
HCPL-J314
2
Selection Guide
Package Type Part Number Number of Channels
8-pin DIP (300 Mil) HCPL-J314 1
SO16 HCPL-314J 2
Ordering InformationSpecify part number followed by option number (if desired).
Example :
HCPL-J314#XXXX
No option = Standard DIP package, 50 per tube.
300 = Gull Wing Surface Mount Option, 50 per tube.
500 = Tape and Reel Packaging Option.
XXXE = Lead Free Option.
HCPL-314J#YYYY
No option = SO16 Package.
500 = Tape and Reel Packaging Option.
XXXE = Lead Free Option.
Remarks: The notation “#” is used for existing products, while (new) products launched since 15th July2001 and lead free option will use “-”
3
HCPL-J314 Package Outline Drawings
Standard DIP Package
Gull Wing Surface Mount Option 300
1.080 ± 0.320(0.043 ± 0.013)
2.54 ± 0.25(0.100 ± 0.010)
0.51 (0.020) MIN.
0.65 (0.025) MAX.
4.70 (0.185) MAX.
2.92 (0.115) MIN.
5° TYP. 0.254+ 0.076- 0.051
(0.010+ 0.003)- 0.002)
7.62 ± 0.25(0.300 ± 0.010)
6.35 ± 0.25(0.250 ± 0.010)
9.80 ± 0.25(0.386 ± 0.010)
1.78 (0.070) MAX.1.19 (0.047) MAX.
HCPL-J314
YYWW
DATE CODE
DIMENSIONS IN MILLIMETERS AND (INCHES).
5678
4321
NOTE: FLOATING LEAD PROTRUSION IS 0.5 mm (20 mils) MAX.
3.56 ± 0.13(0.140 ± 0.005)
0.635 ± 0.25(0.025 ± 0.010)
12° NOM.
9.65 ± 0.25(0.380 ± 0.010)
0.51 ± 0.130(0.020 ± 0.005)
7.62 ± 0.25(0.300 ± 0.010)
5678
4321
9.80 ± 0.25(0.386 ± 0.010)
6.350 ± 0.25(0.250 ± 0.010)
1.02 (0.040)
1.27 (0.050)
10.9 (0.430)
2.0 (0.080)
LAND PATTERN RECOMMENDATION
1.080 ± 0.320(0.043 ± 0.013)
3.56 ± 0.13(0.140 ± 0.005)
1.780(0.070)MAX.1.19
(0.047)MAX.
2.540(0.100)BSC
0.255 (0.075)0.010 (0.003)
NOTE: FLOATING LEAD PROTRUSION IS 0.5 mm (20 mils) MAX.
DIMENSIONS IN MILLIMETERS (INCHES).TOLERANCES (UNLESS OTHERWISE SPECIFIED): xx.xx = 0.01
Regulatory InformationThe HCPL-J314 has beenapproved by the followingorganizations:
IEC/EN/DIN EN 60747-5-2
Approved under:IEC 60747-5-2:1997 + A1:2002EN 60747-5-2:2001 + A1:2002DIN EN 60747-5-2 (VDE 0884 Teil 2):2003-01
UL
Approval under UL 1577,component recognition programup to VISO = 3750 Vrms. FileE55361.
CSA
Approved under CSA ComponentAcceptance Notice #5, File CA88324.
217 °C
RAMP-DOWN6 °C/SEC. MAX.
RAMP-UP3 °C/SEC. MAX.
150 - 200 °C
260 +0/-5 °C
t 25 °C to PEAK
60 to 150 SEC.
20-40 SEC.
TIME WITHIN 5 °C of ACTUALPEAK TEMPERATURE
tp
tsPREHEAT
60 to 180 SEC.
tL
TL
TsmaxTsmin
25
Tp
TIME
TE
MP
ER
AT
UR
E
NOTES:THE TIME FROM 25 °C to PEAK TEMPERATURE = 8 MINUTES MAX.Tsmax = 200 °C, Tsmin = 150 °C
5
OU
TP
UT
PO
WE
R –
PS
, IN
PU
T C
UR
RE
NT
– I S
00
TS – CASE TEMPERATURE – °C
200
600
400
25
800
50 75 100
200
150 175
PS (mW)
125
100
300
500
700IS (mA)
IEC/EN/DIN EN 60747-5-2 Insulation Characteristics
Description Symbol Characteristic Unit
Installation classification per DIN VDE 0110/1.89, Table 1for rated mains voltage ≤ 150 Vrms I - IVfor rated mains voltage ≤ 300 Vrms I - IIIfor rated mains voltage ≤ 600 Vrms I-II
Climatic Classification 55/100/21
Pollution Degree (DIN VDE 0110/1.89) 2
Maximum Working Insulation Voltage VIORM 891 Vpeak
Input to Output Test Voltage, Method b*VIORM x 1.875=VPR, 100% Production Test with VPR 1670 Vpeaktm=1 sec, Partial discharge < 5 pC
Input to Output Test Voltage, Method a*VIORM x 1.5=VPR, Type and Sample Test, tm=60 sec, VPR 1336 Vpeak
Safety-limiting values - maximum values allowed in theevent of a failure.
Case Temperature TS 175 °CInput Current** IS,INPUT 400 mAOutput Power** PS, OUTPUT 1200 mW
Insulation Resistance at TS, VIO = 500 V RS >109 Ω
* Refer to the optocoupler section of the Isolation and Control Components Designer’s Catalog, under Product Safety Regulationssection, IEC/EN/DIN EN 60747-5-2 for a detailed description of Method a and Method b partial discharge test profiles.
** Refer to the following figure for dependence of PS and IS on ambient temperature.
6
Insulation and Safety Related Specifications
Parameter Symbol HCPL-J314 Units Conditions
Minimum External Air Gap L(101) 7.4 mm Measured from input terminals(Clearance) to output terminals, shortest
distance through air.
Minimum External Tracking L(102) 8.0 mm Measured from input terminals(Creepage) to output terminals, shortest
distance path along body.
Minimum Internal Plastic Gap 0.5 mm Through insulation distance(Internal Clearance) conductor to conductor, usually
the straight line distancethickness between the emitterand detector.
Tracking Resistance CTI >175 V DIN IEC 112/VDE 0303 Part 1 (Comparative Tracking Index)
Isolation Group IIIa Material Group (DIN VDE0110, 1/89, Table 1)
Absolute Maximum Ratings
Parameter Symbol Min. Max. Units Note
Storage Temperature TS -55 125 °C
Operating Temperature TA -40 100 °CAverage Input Current IF(AVG) 25 mA 1
Package CharacteristicsFor each channel unless otherwise specified.
Test
Parameter Symbol Min. Typ. Max. Units Conditions Fig. Note
Input-Output Momentary VISO 3750 Vrms TA=25°C, 8,9Withstand Voltage RH<50% for
Output-Output Momentary VO-O 1500 Vrms1 min. 15
Withstand Voltage
Input-Output Resistance RI-O 1012 Ω VI-O=500 V 9
Input-Output Capacitance CI-O 1.2 pF Freq=1 MHz
Notes:
1. Derate linearly above 70°C free air temperature at a rate of 0.3 mA/°C.2. Maximum pulse width = 10 µs, maximum duty cycle = 0.2%. This value is intended to allow for component tolerances for designs
with IO peak minimum = 0.4 A. See Application section for additional details on limiting IOL peak.3. Derate linearly above 85°C, free air temperature at the rate of 4.0 mW/°C.4. Input power dissipation does not require derating.5. Maximum pulse width = 50 µs, maximum duty cycle = 0.5%.6. In this test, VOH is measured with a DC load current. When driving capacitive load VOH will approach VCC as IOH approaches zero
amps.7. Maximum pulse width = 1 ms, maximum duty cycle = 20%.8. In accordance with UL 1577, each HCPL-J314 optocoupler is proof tested by applying an insulation test voltage ≥ 5000 Vrms for
1 second (leakage detection current limit II-O ≤ 5 µA). This test is performed before 100% production test for partial discharge(method B) shown in the IEC/EN/DIN EN 60747-5-2 Insulation Characteristics Table, if applicable.
9. Device considered a two-terminal device: pins on input side shorted together and pins on output side shorted together.10. PDD is the difference between tPHL and tPLH between any two parts or channels under the same test conditions.11. Common mode transient immunity in the high state is the maximum tolerable |dVcm/dt| of the common mode pulse VCM to
assure that the output will remain in the high state (i.e. Vo > 6.0 V).12. Common mode transient immunity in a low state is the maximum tolerable |dVCM/dt| of the common mode pulse, VCM, to assure
that the output will remain in a low state (i.e. Vo < 1.0 V).13. This load condition approximates the gate load of a 1200 V/25 A IGBT.14. For each channel. The power supply current increases when operating frequency and Qg of the driven IGBT increases.15. Device considered a two terminal device: Channel one output side pins shorted together, and channel two output side pins shorted
together.
9
Figure 1. VOH vs. Temperature. Figure 2. IOH vs. Temperature. Figure 3. VOH vs. IOH.
Figure 4. VOL vs. Temperature. Figure 5. IOL vs. Temperature. Figure 6. VOL vs. IOL.
Figure 7. ICC vs. Temperature. Figure 8. ICC vs. VCC. Figure 9. IFLH vs. Temperature.
(VO
H-V
CC
) –
HIG
H O
UT
PU
T V
OL
TA
GE
DR
OP
– V
-50-2.5
TA – TEMPERATURE – °C
125-25
0
0 25 75 10050
-2.0
-1.5
-1.0
-0.5
I OH
– O
UT
PU
T H
IGH
CU
RR
EN
T –
A-50
0.30
TA – TEMPERATURE – °C
125-25
0.40
0 25 75 10050
0.32
0.34
0.36
0.38
0-6
IOH – OUTPUT HIGH CURRENT – A
0.6
0
0.2 0.4
-5
-4
-3
-1
(VO
H-V
CC
) –
OU
TP
UT
HIG
H V
OL
TA
GE
DR
OP
– V
-2
VOH
VO
L –
OU
TP
UT
LO
W V
OL
TA
GE
– V
-500.39
TA – TEMPERATURE – °C
125-25
0.44
0 25 75 10050
0.40
0.41
0.42
0.43
I OL
– O
UT
PU
T L
OW
CU
RR
EN
T –
A
-500.440
TA – TEMPERATURE – °C
125-25
0.470
0 25 75 10050
0.450
0.455
0.460
0.465
0.445
I CC
– S
UP
PL
Y C
UR
RE
NT
– m
A
-500
TA – TEMPERATURE – °C
125-25
1.4
0 25 75 10050
0.4
0.6
0.8
1.2
0.2
1.0
ICCL
ICCH I CC
– S
UP
PL
Y C
UR
RE
NT
– m
A
100
VCC – SUPPLY VOLTAGE – V
3015
1.2
20 25
0.4
0.8
0.2
0.6
1.0
ICCL
ICCH
I FL
H –
LO
W T
O H
IGH
CU
RR
EN
T T
HR
ES
HO
LD
– m
A
-501.5
TA – TEMPERATURE – °C
125-25
3.5
0 25 75 10050
2.0
2.5
3.0
VO
L –
OU
TP
UT
LO
W V
OL
TA
GE
– V
00
IOL – OUTPUT LOW CURRENT – mA
700100
25
400 500
5
20
200 300 600
15
10
10
Figure 10. Propagation Delay vs. VCC. Figure 11. Propagation Delay vs. IF. Figure 12. Propagation Delay vs.
Temperature.
Figure 13. Propagation Delay vs. Rg. Figure 14. Propagation Delay vs. Cg. Figure 15. Transfer Characteristics.
Figure 16. Input Current vs. Forward Voltage.
TP
– P
RO
PA
GA
TIO
N D
EL
AY
– n
s6
0
IF – FORWARD LED CURRENT – mA
18
400
9 1512
100
200
300
-500
TA – TEMPERATURE – °C
125-25
500
0 25 75 10050
100
200
300
400
TP
– P
RO
PA
GA
TIO
N D
EL
AY
– n
s
TPLHTPHL
TP
– P
RO
PA
GA
TIO
N D
EL
AY
– n
s
0200
Rg – SERIES LOAD RESISTANCE – Ω
200
400
50 150100
250
300
350
TPLHTPHL
I F –
FO
RW
AR
D C
UR
RE
NT
– m
A
1.20
VF – FORWARD VOLTAGE – V
1.8
25
1.4 1.6
5
10
15
20
TP
– P
RO
PA
GA
TIO
N D
EL
AY
– n
s
00
Cg – LOAD CAPACITANCE – nF
100
400
20 8060
100
200
300
TPLHTPHL
40
TP
– P
RO
PA
GA
TIO
N D
EL
AY
– n
s
100
VCC – SUPPLY VOLTAGE – V
30
400
15 2520
100
200
300
TPLHTPHL
VO
– O
UT
PU
T V
OL
TA
GE
– V
0-5
IF – FORWARD LED CURRENT – mA
6
25
15
1
35
2 3 4
5
5
0
10
20
30
11
Figure 17. Propagation Delay Test Circuit and Waveforms.
Figure 18. CMR Test Circuit and Waveforms.
0.1 µFVCC = 15to 30 V
47 Ω
1
3
IF = 7 to 16 mA
VO
+–
+–
2
4
8
6
7
5
10 KHz50% DUTY
CYCLE
500 Ω
3 nF
IF
VOUT
tPHLtPLH
tftr
10%
50%
90%
0.1 µF
VCC = 30 V
1
3
IF
VO+–
+–
2
4
8
6
7
5
A
+ –
B
VCM = 1500 V
5 V
VCM
∆t
0 V
VO
SWITCH AT B: IF = 0 mA
VO
SWITCH AT A: IF = 10 mA
VOL
VOH
∆t
VCMδV
δt=
12
Applications InformationEliminating Negative IGBT
Gate Drive
To keep the IGBT firmly off,the HCPL-J314 has a very lowmaximum VOL specification of1.0 V. Minimizing Rg andthe lead inductance from theHCPL-J314 to the IGBT gate andemitter (possibly by mounting theHCPL-J314 on a small PC boarddirectly above the IGBT) can
eliminate the need for negativeIGBT gate drive in manyapplications as shown inFigure 19. Care should be takenwith such a PC board design toavoid routing the IGBT collectoror emitter traces close to theHCPL-J314 input as this canresult in unwanted coupling oftransient signals into the input ofHCPL-J314 and degradeperformance. (If the IGBT
drain must be routed near theHCPL-J314 input, then the LEDshould be reverse biased when inthe off state, to prevent thetransient signals coupled fromthe IGBT drain from turning onthe HCPL-J314.)
Figure 19. Recommended LED Drive and Application Circuit for HCPL-J314.
+ HVDC
3-PHASE AC
- HVDC
0.1 µFVCC = 15 V
1
3
+–
2
4
8
6
7
5
HCPL-J314
Rg
Q1
Q2
270 Ω
+5 V
CONTROLINPUT
74XXXOPEN
COLLECTOR
13
Selecting the Gate Resistor (Rg)
Step 1: Calculate Rg minimum from the IOL peak specification. TheIGBT and Rg in Figure 19 can be analyzed as a simple RC circuit with avoltage supplied by the HCPL-J314.
The VOL value of 5 V in the previous equation is the VOL at the peakcurrent of 0.6A. (See Figure 6).
Step 2: Check the HCPL-J314 power dissipation and increase Rg ifnecessary. The HCPL-J314 total power dissipation (PT) is equal to thesum of the emitter power (PE) and the output power (PO).
PT = PE + PO
PE = IF • VF • Duty Cycle
PO = PO(BIAS) + PO(SWITCHING) = ICC • VCC + ESW (Rg,Qg)• f
where KICC • Qg • f is the increase in ICC due to switching and KICC is aconstant of 0.001 mA/(nC*kHz). For the circuit in Figure 19 with IF(worst case) = 10 mA, Rg = 32 Ω, Max Duty Cycle = 80%,Qg = 100 nC, f = 20 kHz and TAMAX = 85°C:
PE = 10 mA • 1.8 V • 0.8 = 14 mW
PO = (3 mA + (0.001 mA/(nC • kHz)) • 20 kHz • 100 nC) • 24 V +0.4 µJ • 20 kHz = 80 mW
< 260 mW (PO(MAX) @ 85°C)
The value of 3 mA for ICC in the previous equation is the max. ICC overentire operating temperature range.
Since PO for this case is less than PO(MAX), Rg = 32 Ω is alright for thepower dissipation.
= 24 V – 5 V
0.6A
= 32 Ω
Figure 20. Energy Dissipated in the
HCPL-J314 and for Each IGBT
Switching Cycle.
LED Drive CircuitConsiderations for UltraHigh CMR PerformanceWithout a detector shield, thedominant cause of optocouplerCMR failure is capacitivecoupling from the input side ofthe optocoupler, through thepackage, to the detector ICas shown in Figure 21. TheHCPL-J314 improves CMRperformance by using a detectorIC with an optically transparentFaraday shield, which diverts thecapacitively coupled current awayfrom the sensitive IC circuitry.However, this shield does noteliminate the capacitive couplingbetween the LED and opto-coupler pins 5-8 as shown inFigure 22. This capacitivecoupling causes perturbations inthe LED current during commonmode transients and becomes themajor source of CMR failures fora shielded optocoupler. The maindesign objective of a high CMRLED drive circuit becomeskeeping the LED in the properstate (on or off ) during commonmode transients. For example,the recommended applicationcircuit (Figure 19), can achieve10 kV/µs CMR while minimizingcomponent complexity.
Techniques to keep the LED inthe proper state are discussed inthe next two sections.
Rg ≥ VCC – VOL
IOLPEAK
Esw
– E
NE
RG
Y P
ER
SW
ITC
HIN
G C
YC
LE
– µ
J
00
Rg – GATE RESISTANCE – Ω
100
1.5
20
4.0
40
1.0
60 80
3.5Qg = 50 nC
Qg = 100 nC
Qg = 200 nC
Qg = 400 nC3.0
2.0
0.5
2.5
14
Figure 21. Optocoupler Input to Output
Capacitance Model for Unshielded Optocouplers.
Figure 22. Optocoupler Input to Output
Capacitance Model for Shielded Optocouplers.
Figure 23. Equivalent Circuit for Figure 17 During Common
Mode Transient.
Figure 24. Not Recommended Open Collector
Drive Circuit.
Figure 25. Recommended LED Drive Circuit for Ultra-High
CMR IPM Dead Time and Propagation Delay Specifications.
1
3
2
4
8
6
7
5
CLEDP
CLEDN
1
3
2
4
8
6
7
5
CLEDP
CLEDN
SHIELD
CLEDO1
CLEDO2
Rg
1
3
VSAT
2
4
8
6
7
5
+
VCM
ILEDP
CLEDP
CLEDN
SHIELD
* THE ARROWS INDICATE THE DIRECTIONOF CURRENT FLOW DURING –dVCM/dt.
+5 V
+– VCC = 18 V
• • •
• • •
0.1µF
+
–
–
1
3
2
4
8
6
7
5
CLEDP
CLEDN
SHIELD
+5 V
Q1ILEDN
1
3
2
4
8
6
7
5
CLEDP
CLEDN
SHIELD
+5 V
15
CMR with the LED On
(CMRH)
A high CMR LED drive circuitmust keep the LED on duringcommon mode transients. This isachieved by overdriving the LEDcurrent beyond the inputthreshold so that it is not pulledbelow the threshold during atransient. A minimum LEDcurrent of 8 mA providesadequate margin over themaximum IFLH of 5 mA toachieve 10 kV/µs CMR.
CMR with the LED Off
(CMRL)
A high CMR LED drivecircuit must keep the LED off(VF ≤ VF(OFF)) during commonmode transients. For example,during a -dVCM/dt transient inFigure 23, the current flowingthrough CLEDP also flowsthrough the RSAT and VSAT of thelogic gate. As long as the lowstate voltage developed acrossthe logic gate is less than VF(OFF)the LED will remain off and nocommon mode failure will occur.
The open collector drive circuit,shown in Figure 24, can not keepthe LED off during a +dVCM/dttransient, since all the currentflowing through CLEDN must be
supplied by the LED, and it isnot recommended forapplications requiring ultra highCMR1 performance. Thealternative drive circuit whichlike the recommendedapplication circuit (Figure 19),does achieve ultra high CMRperformance by shunting theLED in the off state.
IPM Dead Time and
Propagation Delay
Specifications
The HCPL-J314 includes aPropagation Delay Difference(PDD) specification intended tohelp designers minimize “deadtime” in their power inverterdesigns. Dead time is the timehigh and low side powertransistors are off. Any overlapin Ql and Q2 conduction willresult in large currents flowingthrough the power devices fromthe high-voltage to the low-voltage motor rails. To minimizedead time in a given design, theturn on of LED2 should bedelayed (relative to the turn offof LED1) so that under worst-case conditions, transistor Q1has just turned off whentransistor Q2 turns on, as shownin Figure 26. The amount of
delay necessary to achieve thiscondition is equal to themaximum value of thepropagation delay differencespecification, PDD max, which isspecified to be 500 ns over theoperating temperature range of-40° to 100°C.
Delaying the LED signal by themaximum propagation delaydifference ensures that theminimum dead time is zero, but itdoes not tell a designer what themaximum dead time will be. Themaximum dead time is equivalentto the difference between themaximum and minimumpropagation delay differencespecification as shown inFigure 27. The maximum deadtime for the HCPL-J314 is 1 µs(= 0.5 µs - (-0.5 µs)) over theoperating temperature range of-40°C to 100°C.
Note that the propagation delaysused to calculate PDD and deadtime are taken at equaltemperatures and test conditionssince the optocouplers underconsideration are typicallymounted in close proximity toeach other and are switchingidentical IGBTs.
Figure 26. Minimum LED Skew for Zero Dead Time.
Figure 27. Waveforms for Dead Time.
tPLHMIN
MAXIMUM DEAD TIME(DUE TO OPTOCOUPLER)= (tPHL MAX - tPHL MIN) + (tPLH MAX - tPLH MIN)= (tPHL MAX - tPLH MIN) – (tPHL MIN - tPLH MAX)= PDD* MAX – PDD* MIN
*PDD = PROPAGATION DELAY DIFFERENCENOTE: FOR DEAD TIME AND PDD CALCULATIONS ALL PROPAGATIONDELAYS ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.
VOUT1
ILED2
VOUT2
ILED1
Q1 ON
Q2 OFF
Q1 OFF
Q2 ON
tPHL MIN
tPHL MAX
tPLH MAX
PDD* MAX
(tPHL-tPLH) MAX
tPHL MAX
tPLH MIN
PDD* MAX = (tPHL- tPLH)MAX = tPHL MAX - tPLH MIN
*PDD = PROPAGATION DELAY DIFFERENCENOTE: FOR PDD CALCULATIONS THE PROPAGATION DELAYSARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.