0.4 Amp Output Current IGBT Gate Drive Optocoupler
Data Sheet
Description
The HCPL-3020 and HCPL-0302 consist of a GaAsP 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-0314/3140 (0.6 A), HCPL-3150 (0.6 A) or
HCPL-3120 (2.5 A) gate drive opto-couplers can be used.
Functional Diagram
Truth Table
LEDV
OFFLOW
ONHIGH
O
Features
• 0.4 A maximum peak output current
• 0.2 A minimum peak output current
• High speed response: 0.7 µs maximum propagation
delay over temperature range
• Ultra high CMR: minimum 10 kV/µs at VCM = 1000 V
• Bootstrappable supply current: maximum 3 mA
• Wide operating temperature range: –40°C to 100°C
• Wide VCC operating range: 10 V to 30 V over temperature range
• Available in DIP 8 and SO-8 packages
• Safety approvals: UL approval, 3750 V
for 1 minute
RMS
• CSA approval
• IEC/EN/DIN EN 60747-5-2 approval
V
V
IORM
IORM
= 630 V
= 566 V
(HCPL-3020),
PEAK
(HCPL-0302)
PEAK
Applications
• Isolated IGBT/power MOSFET gate drive
• AC and brushless DC motor drives
• Industrial inverters
• Air conditioner
• Washing machine
• Induction heater for cooker
• Switching power supplies (SPS)
Note:
A 0.1 uF 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 prevent damage and /or degradation which may be induced by ESD.
Page 2
Ordering Information
9.65 ± 0.25
(0.380 ± 0.010)
1.78 (0.070) MAX.
1.19 (0.047) MAX.
A XXXXZ
YYWW
DATE CODE
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.
5678
4321
5 TYP.
OPTION CODE*
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)
TYPE NUMBER
DIMENSIONS IN MILLIMETERS AND (INCHES).
* MARKING CODE LETTER FOR OPTION NUMBERS.
"V" = OPTION 060
OPTION NUMBERS 300 AND 500 NOT MARKED.
NOTE:
FLOATING LEAD PROTUSION IS 0.25 mm (10 mils) MAX.
3.56 ± 0.13
(0.140 ± 0.005)
Specify part number followed by option number (if desired).
Example:
HCPL-3020-XXXX
No option = Standard DIP package, 50 per tube
300 = Gull Wing Surface Mount Option, 50 per tube
500 = Tape and Reel Packaging Option
060 = IEC/EN/DIN EN 60747-5-2, V
XXXE = Lead Free Option
HCPL-0302-XXXX
No option = Standard SO-8 package, 100 per tube
500 = Tape and Reel Packaging Option
060 = IEC/EN/DIN EN 60747-5-2, V
XXXE = Lead Free Option
Package Outline Drawings
HCPL-3020 Standard DIP Package
IORM
IORM
= 630 V
= 566 V
PEAK
PEAK
2
Page 3
HCPL-3020 Gull Wing Surface Mount Option 300
0.635 ± 0.25
(0.025 ± 0.010)
12 NOM.
0.20 (0.008)
0.33 (0.013)
9.65 ± 0.25
(0.380 ± 0.010)
0.635 ± 0.130
(0.025 ± 0.005)
7.62 ± 0.25
(0.300 ± 0.010)
5
6
7
8
4
3
2
1
9.65 ± 0.25
(0.380 ± 0.010)
6.350 ± 0.25
(0.250 ± 0.010)
1.016 (0.040)
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.
2.54
(0.100)
BSC
DIMENSIONS IN MILLIMETERS (INCHES).
LEAD COPLANARITY = 0.10 mm (0.004 INCHES).
1.27 (0.050)
NOTE: FLOATING LEAD PROTUSION IS 0.25 mm (10 mils) MAX.
XXX
YWW
8765
4321
5.994 ± 0.203
(0.236 ± 0.008)
3.937 ± 0.127
(0.155 ± 0.005)
0.406 ± 0.076
(0.016 ± 0.003)
1.270
(0.050)
BSC
5.080 ± 0.127
(0.200 ± 0.005)
3.175 ± 0.127
(0.125 ± 0.005)
1.524
(0.060)
45 X
0.432
(0.017)
0.228 ± 0.025
(0.009 ± 0.001)
TYPE NUMBER
(LAST 3 DIGITS)
DATE CODE
0.305
(0.012)
MIN.
TOTAL PACKAGE LENGTH (INCLUSIVE OF MOLD FLASH)
5.207 ± 0.254 (0.205 ± 0.010)
DIMENSIONS IN MILLIMETERS (INCHES).
LEAD COPLANARITY = 0.10 mm (0.004 INCHES) MAX.
0.203 ± 0.102
(0.008 ± 0.004)
7
PIN ONE
0 ~ 7
*
*
7.49 (0.295)
1.9 (0.075)
0.64 (0.025)
Land Pattern Recommendation
NOTE: FLOATING LEAD PROTUSION IS 0.15 mm (6 mils) MAX.
HCPL-0302 Small Outline SO-8 Package
3
Page 4
Solder Reow Temperature Prole
217 ˚C
RAMP-DOWN
6 ˚C/SEC. MAX.
RAMP-UP
3 ˚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 ACTUAL
PEAK TEMPERATURE
t
p
t
s
PREHEAT
60 to 180 SEC.
t
L
T
L
T
smax
T
smin
25
T
p
TIME (SECONDS)
TEMPERATURE (˚C)
NOTES:
THE TIME FROM 25 ˚C to PEAK TEMPERATURE = 8 MINUTES MAX.
T
Note: Use of non-chlorine-activated fluxes is highly recommended
Recommended Solder Reow Temperature Prole (Lead free)
Note: Use of non-chlorine-activated fluxes is highly recommended
4
Page 5
Regulatory Information
OUTPUT POWER – P
S
, INPUT CURRENT – I
S
0
0
TS – CASE TEMPERATURE – C
200
600
400
25
800
50 75 100
200
150 175
PS (mW)
125
100
300
500
700
IS (mA)
The HCPL-0302/3020 has been approved by the following organizations:
IEC/EN/DIN EN 60747-5-2
Approved under:
IEC 60747-5-2:1997 + A1:2002
UL
Approval under UL 1577, component recognition program up to V
= 3750 V
ISO
. File E55361.
RMS
EN 60747-5-2:2001 + A1:2002
DIN EN 60747-5-2 (VDE 0884 Teil 2):2003-01.
(Option 060 only)
CSA
Approval under CSA Component Acceptance Notice #5,
File CA 88324.
IEC/EN/DIN EN 60747-5-2 Insulation Characteristics (HCPL-3020 and HCPL-0302 Option 060)
Description Symbol HCPL-3020 HCPL-0302 Unit
Installation Classication per DIN VDE 0110/1.89, Table 1
for Rated Mains Voltage 150 V
for Rated Mains Voltage 300 V
for Rated Mains Voltage 600 V
I – IV I – IV
rms
I – III I – III
rms
I – II
rms
Climatic Classication 55/100/21 55/100/21
Pollution Degree (DIN VDE 0110/1.89) 2 2
Maximum Working Insulation Voltage V
Input to Output Test Voltage, Method b
V
x 1.875 = VPR, 100% Production Test with tm = 1 sec,
IORM
[1]
Partial Discharge < 5 pC VPR 1181 1050 V
Input to Output Test Voltage, Method a
V
x 1.5 = VPR, Type and Sample Test, tm = 60 sec,
IORM
[1]
Partial Discharge < 5 pC VPR 945 840 V
630 566 V
IORM
peak
peak
peak
Highest Allowable Overvoltage
(Transient Overvoltage t
= 10 sec) V
ini
6000 4000 V
IOTM
peak
Safety-Limiting Values – Maximum Values Allowed in the Event of a
Failure.
Case Temperature TS 175 150 °C
Input Current
Output Power
[2]
I
[2]
P
230 150 mA
S, INPUT
S, OUTPUT
600 600 mW
Insulation Resistance at TS, VIO = 500 V RS >109 >109 Ω
1. Refer to the optocoupler section of the Isolation and Control Components Designer’s Catalog, under Product Safety Regulations section,
(IEC/EN/DIN EN 60747-5-2), for a detailed description of Method a
and Method b partial discharge test proles.
2. Refer to the following gure for dependence of PS and IS on ambient
temperature.
5
Page 6
Insulation and Safety Related Specications
Parameter Symbol HCPL-3020 HCPL-0302 Units Conditions
Minimum External Air Gap L(101) 7.1 4.9 mm Measured from input terminals to output
(Clearance) terminals, shortest distance through air.
Minimum External Tracking L(102) 7.4 4.8 mm Measured from input terminals to output
(Creepage) terminals, shortest distance path along
body.
Minimum Internal Plastic Gap 0.08 0.08 mm Through insulation distance conductor to
(Internal Clearance) conductor, usually the straight line distance
thickness between the emitter and
detector.
Tracking Resistance CTI >175 >175 V DIN IEC 112/VDE 0303 Part 1
(Comparative Tracking
Index)
Isolation Group IIIa IIIa Material Group (DIN VDE 0110, 1/89,
Table 1)
Absolute Maximum Ratings
Parameter Symbol Min. Max. Units Note
Storage Temperature TS –55 125 °C
Operating Temperature TA –40 100 °C
Average Input Current I
Peak Transient Input Current (<1 µs pulse width, 300 pps) I
20 mA 1
F(AVG)
1.0 A
F(TRAN)
Reverse Input Voltage VR 5 V
“High” Peak Output Current I
“Low” Peak Output Current I
OH(PEAK)
OL(PEAK)
0.4 A 2
0.4 A 2
Supply Voltage VCC – VEE –0.5 35 V
Output Voltage V
–0.5 VCC V
O(PEAK)
Output Power Dissipation PO 250 mW 3
Input Power Dissipation PI 45 mW 4
Lead Solder Temperature 260°C for 10 sec., 1.6 mm below seating plane
Solder Reow Temperature Prole See Package Outline Drawings section
Recommended Operating Conditions
Parameter Symbol Min. Max. Units Note
Power Supply VCC - VEE 10 30 V
Input Current (ON) I
Input Voltage (OFF) V
7 12 mA
F(ON)
–3.0 0.8 V
F(OFF)
Operating Temperature TA –40 100 °C
6
Page 7
Electrical Specications (DC)
Over recommended operating conditions unless otherwise specied.
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig.
Note
High Level Output Current IOH 0.15 A VO = VCC – 4 5
0.20.3AVO = VCC – 10 2 2
Low Level Output Current IOL 0.15 A VO = VEE + 2.5 5
0.20.3AVO = VEE + 10 4 2
High Level Output Voltage VOH V
CC
– 4 V
– 1.8 V IO = –100 mA 1 6, 7
CC
Low Level Output Voltage VOL 0.4 1 V IO = 100 mA 3
High Level Supply Current I
Low Level Supply Current I
Threshold Input Current Low to High I
VO > 5 V
Threshold Input Voltage High to Low V
0.7 3 mA IO = 0 mA 5, 6 14
CCH
1.2 3 mA IO = 0 mA
CCL
6 mA IO = 0 mA, 7, 13
FLH
0.8 V
FHL
Input Forward Voltage VF 1.2 1.5 1.8 V IF = 10 mA 14
Temperature Coecient of Input DVF/DTA –1.6 mV/°C
Forward Voltage
Input Reverse Breakdown Voltage BVR 5 V IR = 10 µA
Input Capacitance CIN 60 pF f = 1 MHz,
VF = 0 V
Switching Specications (AC)
Over recommended operating conditions unless otherwise specied.
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Note
Propagation Delay Time to Hight
0.10.20.7µsRg=75Ω, Cg = 1.5 nF, 8, 9 14
PLH
Output Level f = 10 kHz, Duty Cycle = 50%, 10, 11
IF = 7 mA, VCC = 30 V 12, 15
Propagation Delay Time to Low t
0.1 0.2 0.7 µs
PHL
Output Level
Propagation Delay Dierence PDD –0.5 0.5 µs 10
Between Any Two Parts or Channels
Rise Time tR 50 ns
Fall Time tF 50 ns
Output High Level Common Mode |CMH| 10 kV/µs TA = 25°C, VCM = 1000 V 16 11
Transient Immunity
Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Note
Input-Output MomentaryV
3750V
ISO
TA = 25°C, RH < 50% 8, 9
rms
Withstand Voltage
Input-Output Resistance R
Input-Output Capacitance C
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 = 0.2 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 optocoupler is proof tested by applying an insulation test voltage >4500 V
tion current limit I
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 dierence between t
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/20 A IGBT.
14. The power supply current increases when operating frequency and Cg of the driven IGBT increases.
< 5 µA). This test is performed before 100% production test for partial discharge (method B) shown in the IEC/EN/DIN EN
I-O
and t
PHL
1012 Ω V
I-O
0.6 pF Freq = 1 MHz
I-O
between any two parts or channels under the same test conditions.
PLH
= 500 V 9
I-O
for 1 second (leakage detec-
rms
Figure 1. VOH vs. temperature.
8
Figure 2. VOH vs. IOH.
Figure 3. VOL vs. temperature.
Page 9
Figure 4. VOL vs. IOL.Figure 5. ICC vs. temperature.Figure 6. ICC vs. VCC.
V
OL
– OUTPUT LOW VOLTAGE DROP – V
0
0
IOL – OUTPUT LOW CURRENT – A
0.4
5
0.2
1
4
0.10.3
3
2
I
CC
– SUPPLY CURRENT – mA
-50
0
TA – TEMPERATURE – C
125-25
1.4
02575 10050
0.4
0.6
0.8
1.2
0.2
1.0
ICCL
ICCH
I
CC
– SUPPLY CURRENT – mA
10
0
VCC – SUPPLY VOLTAGE – V
3015
1.2
2025
0.4
0.8
0.2
0.6
1.0
ICCL
ICCH
I
FLH
– LOW TO HIGH CURRENT THRESHOLD – mA
-50
1.5
TA – TEMPERATURE – C
125-25
3.5
02575 10050
2.0
2.5
3.0
T
P
– PROPAGATION DELAY – ns
10
0
VCC – SUPPLY VOLTAGE – V
30
400
152520
100
200
300
T
PLH
T
PHL
T
P
– PROPAGATION DELAY – ns
6
0
IF – FORWARD LED CURRENT – mA
18
400
91512
100
200
300
-50
0
TA – TEMPERATURE – C
125-25
500
02575 10050
100
200
300
400
T
P
– PROPAGATION DELAY – ns
T
PLH
T
PHL
T
P
– PROPAGATION DELAY – ns
0
200
Rg – SERIES LOAD RESISTANCE – Ω
200
400
50150100
250
300
350
T
PLH
T
PHL
T
P
– PROPAGATION DELAY – ns
0
0
Cg – LOAD CAPACITANCE – nF
100
400
208060
100
200
300
T
PLH
T
PHL
40
Figure 7. I
Figure 10. Propagation delay vs. tempera-
9
vs. temperature.Figure 8. Propagation delay vs. VCC.Figure 9. Propagation delay vs. IF.
FLH
Figure 11. Propagation delay vs. Rg.
Figure 12. Propagation delay vs. C
g.
Page 10
Figure 13. Transfer characteristics.
0.1 µF
V
CC
= 15
to 30 V
75 Ω
1
3
IF = 7 to 16 mA
V
O
+
–
+
–
2
4
8
6
7
5
10 KHz
50% DUTY
CYCLE
500 Ω
1.5 nF
I
F
V
OUT
t
PHL
t
PLH
t
f
t
r
10%
50%
90%
0.1 µF
V
CC
= 30 V
1
3
I
F
V
O
+
–
+
–
2
4
8
6
7
5
A
+
–
B
V
CM
= 1000 V
5 V
V
CM
∆t
0 V
V
O
SWITCH AT B: IF = 0 mA
V
O
SWITCH AT A: IF = 10 mA
V
OL
V
OH
∆t
V
CM
δV
δt
=
I
F
– FORWARD CURRENT – mA
1.2
0
VF – FORWARD VOLTAGE – V
1.8
25
1.41.6
5
10
15
20
V
O
– OUTPUT VOLTAGE – V
0
-5
IF – FORWARD LED CURRENT – mA
6
25
15
13523455
0
10
20
30
Figure 15. Propagation delay test circuits and waveforms.
Figure 14. Input current vs. forward voltage.
Figure 16. CMR test circuits and waveforms.
10
Page 11
Applications Information Eliminating Negative IGBT
+ HVDC
3-PHASE
AC
- HVDC
0.1 µF
V
CC
= 15 V
1
3
+
–
2
4
8
6
7
5
HCPL-3020/0302
Rg
Q1
Q2
270 Ω
+5 V
CONTROL
INPUT
74XXX
OPEN
COLLECTOR
Gate Drive
To keep the IGBT rmly o, the HCPL-3020 and HCPL0302 have a very low maximum VOL specication of
1.0 V. Minimizing Rg and the lead inductance from the
HCPL-3020 or HCPL-0302 to the IGBT gate and emitter
(possibly by mounting the HCPL-3020 or HCPL-0302 on a
small PC board directly above the IGBT) can eliminate the
need for negative IGBT gate drive in many applications as
shown in Figure 17. Care should be taken with such a PC
board design to avoid routing the IGBT collector or emitter traces close to the HCPL-3020 or HCPL-0302 input as
this can result in unwanted coupling of transient signals
into the input of HCPL-3020 or HCPL-0302 and degrade
performance. (If the IGBT drain must be routed near the
HCPL-3020 or HCPL-0302 input, then the LED should be
reverse biased when in the o state, to prevent the transient
signals coupled from the IGBT drain from turning on the
HCPL-3020 or HCPL-0302.
Figure 17. Recommended LED drive and application circuit for HCPL-3020 and HCPL-0302.
11
Page 12
Selecting the Gate Resistor (Rg) for HCPL-3020
Esw – ENERGY PER SWITCHING CYCLE – µJ
0
0
Rg – GATE RESISTANCE – Ω
100
1.5
20
4.0
40
1.0
6080
3.5
Qg = 50 nC
Qg = 100 nC
Qg = 200 nC
Qg = 400 nC
3.0
2.0
0.5
2.5
Step 1: Calculate Rg minimum from the IOL peak specication. The IGBT and Rg in Figure 17 can be analyzed as a
simple RC circuit with a voltage supplied by the HCPL-3020.
Rg ≤ VCC – V
I
OL
OLPEAK
= 24 - 1
0.4
= 57.5 Ω
The VOL value of 1 V in the previous equation is the VOL at the peak current of 0.4 A. (See Figure 4).
Step 2: Check the HCPL-3020 power dissipation and increase Rg if necessary. The HCPL-3020 total power dissipation
(PT) is equal to the sum of the emitter power (PE) and the output power (PO).
PT = PE + P
O
PE = IF • VF • Duty Cycle
PO = P
= (I
where K
CCBIAS
• Qg • f is the increase in ICC due to switching and K
ICC
in Figure 17 with IF (worst case) = 10 mA, Rg = 57.5 Ω, Max Duty Cycle = 80%, Qg = 100 nC, f = 20 kHz and T
O(BIAS)
+ K
+ P
O(SWITCHING)
• Qg • f) • VCC + E
ICC
= ICC • VCC + E
SW (Rg;Qg
SW (Rg;Qg
) • f
) • f
is a constant of 0.001 mA/(nC*kHz). For the circuit
ICC
AMAX
=
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 + 0.3mJ • 20 kHz
= 126 mW < 250 mW (P
The value of 3 mA for ICC in the previous equation is the max. ICC over entire operating temperature range.
Since PO for this case is less than P
Figure 18. Energy dissipated in the HCPL-3020 and HCPL-0302
and for each IGBT switching cycle.
12
) @ 85°C
O(MAX)
, Rg = 57.5 Ω is alright for the power dissipation.
O(MAX)
Page 13
LED Drive Circuit Considerations for Ultra High CMR
1
3
2
4
8
6
7
5
C
LEDP
C
LEDN
1
3
2
4
8
6
7
5
C
LEDP
C
LEDN
SHIELD
C
LEDO1
C
LEDO2
Rg
1
3
V
SAT
2
4
8
6
7
5
+
V
CM
I
LEDP
C
LEDP
C
LEDN
SHIELD
* THE ARROWS INDICATE THE DIRECTION
OF CURRENT FLOW DURING –dVCM/dt.
+5 V
+
–
V
CC
= 18 V
• • •
• • •
0.1
µF
+
–
–
1
3
2
4
8
6
7
5
C
LEDP
C
LEDN
SHIELD
+5 V
Q1
I
LEDN
1
3
2
4
8
6
7
5
C
LEDP
C
LEDN
SHIELD
+5 V
Performance
Without a detector shield, the dominant cause of optocoupler CMR failure is capacitive coupling from the input side
of the optocoupler, through the package, to the detector
IC as shown in Figure 19. The HCPL-3020 and HCPL-0302
improve CMR performance by using a detector IC with
an optically transparent Faraday shield, which diverts the
capacitively coupled current away from the sensitive IC
circuitry. However, this shield does not eliminate the capacitive coupling between the LED and optocoupler pins
5-8 as shown in Figure 20. This capacitive coupling causes
perturbations in the LED current during common mode
transients and becomes the major source of CMR failures
for a shielded optocoupler. The main design objective of
a high CMR LED drive circuit becomes keeping the LED in
the proper state (on or o) during common mode transients. For example, the recommended application circuit
(Figure 17), can achieve 10 kV/µs CMR while minimizing
component complexity.
Techniques to keep the LED in the proper state are discussed in the next two sections.
Figure 19. Optocoupler input to output capacitance model for
unshielded optocouplers.
Figure 20. Optocoupler Input to output capacitance model for
shielded optocouplers.
Figure 22. Not recommended open collector drive circuit.
Figure 21. Equivalent circuit for gure 15 during common mode
transient.
Figure 23. Recommended LED drive circuit for ultra-high CMR IPM
dead time and propagation delay specications.
13
Page 14
CMR with the LED On (CMRH)
A high CMR LED drive circuit must keep the LED on during
common mode transients. This is achieved by overdriving
the LED current beyond the input threshold so that it is not
pulled below the threshold during a transient. A minimum
LED current of 7 mA provides adequate margin over the
maximum I
of 6 mA to achieve 10 kV/µs CMR.
FLH
CMR with the LED O (CMRL)
A high CMR LED drive circuit must keep the LED o (VF
V
) during common mode transients. For example,
F(OFF)
during a -dVCM/dt transient in Figure 21, the current owing through C
also ows through the R
LEDP
SAT
and V
SAT
of
the logic gate. As long as the low state voltage developed
across the logic gate is less than V
the LED will remain
F(OFF)
o and no common mode failure will occur.
The open collector drive circuit, shown in Figure 22, cannot
keep the LED o during a +dVCM/dt transient, since all the
current owing through C
must be supplied by the
LEDN
LED, and it is not recommended for applications requiring
ultra high CMR1 performance. The alternative drive circuit,
which likes the recommended application circuit (Figure
17), does achieve ultra high CMR performance by shunting
the LED in the o state.
Dead Time and Propagation Delay Specications
The HCPL-3020 and HCPL-0302 include a Propagation
Delay Dierence (PDD) specication intended to help
designers minimize “dead time” in their power inverter
designs. Dead time is the time high and low side power
transistors are o. Any overlap in Ql and Q2 conduction
will result in large currents owing through the power
devices from the high voltage to the low-voltage motor
rails. To minimize dead time in a given design, the turn
on of LED2 should be delayed (relative to the turn o of
LED1) so that under worst-case conditions, transistor Q1
has just turned o when transistor Q2 turns on, as shown
in Figure 24. The amount of delay necessary to achieve
this condition is equal to the maximum value of the propagation delay dierence specication, PDD max, which is
specied to be 500 ns over the operating temperature
range of –40° to 100°C.
Delaying the LED signal by the maximum propagation
delay dierence ensures that the minimum dead time is
zero, but it does not tell a designer what the maximum
dead time will be. The maximum dead time is equivalent
to the dierence between the maximum and minimum
propagation delay dierence specication as shown in
Figure 25. The maximum dead time for the HCPL-3020 and
HCPL-0302 is 1 ms (= 0.5 µs – (–0.5 µs)) over the operating
temperature range of –40°C to 100°C.
Note that the propagation delays used to calculate PDD and dead time are
taken at equal temperatures and test conditions since the optocouplers
under consideration are typically mounted in close proximity to each
other and are switching identical IGBTs.
14
Page 15
t
PHL MAX
t
PLH MIN
PDD* MAX = (t
PHL- tPLH)MAX
= t
PHL MAX - tPLH MIN
*PDD = PROPAGATION DELAY DIFFERENCE
NOTE: FOR PDD CALCULATIONS THE PROPAGATION DELAYS
ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.
V
OUT1
I
LED2
V
OUT2
I
LED1
Q1 ON
Q2 OFF
Q1 OFF
Q2 ON
t
PLH
MIN
MAXIMUM DEAD TIME
(DUE TO OPTOCOUPLER)
= (t
PHL MAX - tPHL MIN
) + (t
PLH MAX - tPLH MIN
)
= (t
PHL MAX - tPLH MIN
) – (t
PHL MIN - tPLH MAX
)
= PDD* MAX – PDD* MIN
*PDD = PROPAGATION DELAY DIFFERENCE
NOTE: FOR DEAD TIME AND PDD CALCULATIONS ALL PROPAGATION
DELAYS ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.
V
OUT1
I
LED2
V
OUT2
I
LED1
Q1 ON
Q2 OFF
Q1 OFF
Q2 ON
t
PHL MIN
t
PHL MAX
t
PLH MAX
PDD* MAX
(t
PHL-tPLH) MAX
Figure 24. Minimum LED skew for zero dead time.
Figure 25. Waveforms for dead time.
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