AVAGO HCPL-J314

HCPL-J314
0.6 Amp Output Current IGBT Gate Drive Optocoupler
Data Sheet
Lead (Pb) Free
RoHS 6 fully
compliant
RoHS 6 fully compliant options available;
-xxxE denotes a lead-free product
Description
Features
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 (0.6 A) or HCPL-3120
(2.5 A) optocouplers can be used.
• 0.6 A maximum peak output current
• 0.4 A minimum peak output current
• High speed response: 0.7 µs max. propagation delay over temperature
range
• Ultra high CMR: min. 25 kV/µs at VCM = 1.5 kV
• Bootstrappable supply current: max. 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 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
Functional Diagram
N/C
1
8
VCC
ANODE
2
7
VO
CATHODE
3
6
VO
N/C
4
5
VEE
SHIELD
HCPL-J314
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)
Truth Table
LED VO
OFF
LOW
ON
HIGH
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 prevent damage and/or degradation which may be induced by ESD.
Selection Guide
Package Type
Part Number
Number of Channels
8-pin DIP (300 Mil)
HCPL-J314
1
SO16
HCPL-314J
2
Note: Please refer to HCPL-314J datasheet for more details
Ordering Information
HCPL-J314 is UL Recognized with 3750 Vrms for 1 minute per UL1577.
Option
Part
Number
HCPL-J314
RoHS
Compliant
Non RoHS
Compliant
-000E
No option
-300E
#300
-500E
#500
Package
300mil
DIP-8
Surface
Mount
Gull
Wing
X
X
X
X
Tape
& Reel
X
IEC/EN/DIN
EN 60747-5-2
Quantity
X
50 per tube
X
50 per tube
X
1000 per reel
To order, choose a part number from the part number column and combine with the desired option from the option
column to form an order entry.
Example 1: HCPL-J314-500E to order product of 300 mil DIP Gull Wing Surface Mount package in Tape and Reel
packaging with IEC/EN/DIN EN 60747-5-2 Safety Approval in RoHS compliant.
Example 2: HCPL-J314 to order product of 300 mil DIP package in tube packaging with IEC/EN/DIN EN 60747-5-2 Safety
Approval and non RoHS complaint
Option data sheets are available. Contact your Avago sales representative or authorized distributor for information.
Remarks: The notation ‘#XXX’ is used for existing products, while (new) products launched since 15th July 2001 and
RoHS compliant option will use ‘-XXXE‘.
HCPL-J314 Package Outline Drawings
Standard DIP Package
7.62 ± 0.25
(0.300 ± 0.010)
9.80 ± 0.25
(0.386 ± 0.010)
8
7
6
5
HCPL-J314
6.35 ± 0.25
(0.250 ± 0.010)
DATE CODE
YYWW
1
2
3
4
1.78 (0.070) MAX.
1.19 (0.047) MAX.
+ 0.076
0.254 - 0.051
+ 0.003)
(0.010 - 0.002)
5° TYP.
3.56 ± 0.13
(0.140 ± 0.005)
4.70 (0.185) MAX.
0.51 (0.020) MIN.
2.92 (0.115) MIN.
DIMENSIONS IN MILLIMETERS AND (INCHES).
1.080 ± 0.320
(0.043 ± 0.013)
0.65 (0.025) MAX.
NOTE: FLOATING LEAD PROTRUSION IS 0.5 mm (20 mils) MAX.
2.54 ± 0.25
(0.100 ± 0.010)
Gull Wing Surface Mount Option 300
LAND PATTERN RECOMMENDATION
9.80 ± 0.25
(0.386 ± 0.010)
8
7
6
1.02 (0.040)
5
HCPL-J314
YYWW
MOLDED
1
2
3
6.350 ± 0.25
(0.250 ± 0.010)
10.9 (0.430)
4
1.27 (0.050)
9.65 ± 0.25
(0.380 ± 0.010)
1.780
(0.070)
MAX.
1.19
(0.047)
MAX.
7.62 ± 0.25
(0.300 ± 0.010)
3.56 ± 0.13
(0.140 ± 0.005)
1.080 ± 0.320
(0.043 ± 0.013)
0.635 ± 0.25
(0.025 ± 0.010)
2.540
(0.100)
BSC
0.51 ± 0.130
(0.020 ± 0.005)
DIMENSIONS IN MILLIMETERS (INCHES).
TOLERANCES (UNLESS OTHERWISE SPECIFIED): xx.xx = 0.01
xx.xxx = 0.005
NOTE: FLOATING LEAD PROTRUSION IS 0.5 mm (20 mils) MAX.
2.0 (0.080)
0.255 (0.075)
0.010 (0.003)
12° NOM.
LEAD COPLANARITY
MAXIMUM: 0.102 (0.004)
Solder Reflow Temperature Profile
Regulatory Information
The HCPL-J314 has been approved
by the following organizations:
300
TEMPERATURE (°C)
PREHEATING RATE 3°C + 1°C/–0.5°C/SEC.
REFLOW HEATING RATE 2.5°C ± 0.5°C/SEC.
200
PEAK
TEMP.
245°C
PEAK
TEMP.
240°C
2.5°C ± 0.5°C/SEC.
30
SEC.
160°C
150°C
140°C
SOLDERING
TIME
200°C
100
50 SEC.
TIGHT
TYPICAL
LOOSE
ROOM
TEMPERATURE
0
0
50
100
150
200
TIME (SECONDS)
Note: Non-halide flux should be used.
Recommended Pb-Free IR Profile
tp
Tp
TL
TEMPERATURE
PEAK
TEMP.
230°C
30
SEC.
3°C + 1°C/–0.5°C
PREHEATING TIME
150°C, 90 + 30 SEC.
Tsmax
260 +0/-5 °C
TIME WITHIN 5 °C of ACTUAL
PEAK TEMPERATURE
20-40 SEC.
217 °C
RAMP-UP
3 °C/SEC. MAX.
150 - 200 °C
RAMP-DOWN
6 °C/SEC. MAX.
Tsmin
ts
PREHEAT
60 to 180 SEC.
25
tL
60 to 150 SEC.
t 25 °C to PEAK
TIME
NOTES:
THE TIME FROM 25 °C to PEAK TEMPERATURE = 8 MINUTES MAX.
Tsmax = 200 °C, Tsmin = 150 °C
Note: Non-halide flux should be used.
IEC/EN/DIN EN 60747-5-2
Approved under:
IEC 60747-5-2:1997 + A1:2002
EN 60747-5-2:2001 + A1:2002
DIN EN 60747-5-2 (VDE 0884 Teil 2):2003-01 250
UL
Approval under UL 1577, component recognition program up to
VISO = 3750 Vrms. File E55361.
CSA
Approved under CSA Component
Acceptance Notice #5, File CA 88324.
IEC/EN/DIN EN 60747-5-2 Insulation Characteristics
Description
Symbol
Characteristic
Installation classification per DIN VDE 0110/1.89, Table 1
for rated mains voltage ≤ 150 Vrms
for rated mains voltage ≤ 300 Vrms
for rated mains voltage ≤ 600 Vrms
I - IV
I - IV
I - III
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 tm = 1 sec,
Partial discharge < 5 pC
VPR 1670
Vpeak
Input to Output Test Voltage, Method a* VIORM x 1.5 = VPR, Type and Sample Test, tm = 60 sec,
Partial discharge < 5 pC VPR
1336
Vpeak
Highest Allowable Overvoltage (Transient Overvoltage tini = 10 sec)
VIOTM
6000
Vpeak
Safety-limiting values – maximum values allowed in the event of a failure. Case Temperature TS Input Current** IS,INPUT
Output Power**
PS, OUTPUT
175
400
1200
°C
mA
mW
Insulation Resistance at TS, VIO = 500 V
>109
Ω
RS
Unit
*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 profiles.
OUTPUT POWER – PS, INPUT CURRENT – IS
** Refer to the following figure for dependence of PS and IS on ambient temperature.
800
PS (mW)
IS (mA)
700
600
500
400
300
200
100
0
0
25
50
75 100 125 150 175 200
TS – CASE TEMPERATURE – °C
HCPL-J314
Insulation and Safety Related Specifications
Parameter
Symbol
HCPL-J314
Units
Conditions
Minimum External Air Gap
(Clearance)
L(101)
7.4
mm
Measured from input terminals to output
terminals, shortest distance through air.
Minimum External Tracking (Creepage)
L(102)
8.0
mm
Measured from input terminals to output
terminals, shortest distance path along body.
Minimum Internal Plastic Gap
(Internal Clearance)
0.5
mm
Through insulation distance conductor to conductor, usually the straight line distance thickness between the emitter and detector.
Tracking Resistance
(Comparative Tracking Index)
CTI
>175
V
DIN IEC 112/VDE 0303 Part 1
Isolation Group
IIIa Material Group (DIN VDE 0110, 1/89, Table 1)
Absolute Maximum Ratings
Parameter
Symbol
Min.
Max.
Units
Storage Temperature
TS
-55
125
°C
Operating Temperature
TA
-40
100
°C
Average Input Current
IF(AVG)
25
mA
Peak Transient Input Current
(<1 µs pulse width, 300pps)
IF(TRAN)
1.0
A
Reverse Input Voltage
VR
5
V
“High” Peak Output Current
IOH(PEAK)
0.6
A
2
“Low” Peak Output Current
IOL(PEAK)
0.6
A
2
Supply Voltage
VCC - VEE
-0.5
35
V
Output Voltage
VO(PEAK)
-0.5
VCC
V
Output Power Dissipation
PO
260
mW
3
Input Power Dissipation
PI
105
mW
4
Lead Solder Temperature
260°C for 10 sec., 1.6 mm below seating plane
Solder Reflow Temperature Profile
See Package Outline Drawings section
Note
1
Recommended Operating Conditions
Parameter
Symbol
Min.
Max.
Units
Power Supply
VCC - VEE
10
30
V
Input Current (ON)
IF(ON)
8
12
mA
Input Voltage (OFF)
VF(OFF)
-3.6
0.8
V
Operating Temperature
TA
-40
100
°C
Note
Electrical Specifications (DC)
Over recommended operating conditions unless otherwise specified.
Test
Parameter Symbol Min. Typ.
Max. Units Conditions
Fig.
Note
High Level Output Current
IOH
0.2
A
VO = VCC – 4 2
5
0.4
0.5
VO = VCC – 10
3
2
Low Level Output Current
IOL
0.2
0.4
A
VO = VEE + 2.5
5
5
0.4
0.5
VO = VEE+10
6
2
High Level Output Voltage
VOH
VCC-4
VCC-1.8
V
IO = -100 mA
1
6,7
Low Level Output Voltage
VOL
0.4
1
V
IO = 100 mA
4
High Level Supply Current
ICCH
0.7
3
mA
IO = 0 mA
7,8
Low Level Supply Current
ICCL
1.2
3
mA
IO = 0 mA
Threshold Input Current Low to High IFLH
6
mA
9,15
Threshold Input Voltage Low to High VFHL
0.8
V
IO = 0 mA, VO > 5 V
Input Forward Voltage VF
1.2
1.5
1.8
V
IF = 10 mA
16
Temperature Coefficient of Input
Forward Voltage DVF/DTA
-1.6
mV/°C
Input Reverse Breakdown Voltage
BVR
5
V
IR = 10 µA
Input Capacitance
CIN
60
pF
f = 1 MHz,
VF = 0 V
14
Switching Specifications (AC)
Over recommended operating conditions unless otherwise specified.
Test
Parameter
Symbol Min. Typ.
Max. Units Conditions Fig.
Note
Propagation Delay Time to High OutputtPLH
Level
0.1
0.2
0.7
µs
Propagation Delay Time to Low OutputtPHL
Level
0.1
0.3
0.7
µs
Propagation Delay Difference
Between Any Two Parts or Channels
PDD
-0.5
0.5
µs
Rg = 47 Ω, Cg = 3 nF, 10,11, 14
f = 10 kHz, 12,13,
Duty Cycle = 50%, 14,17
f = 10 kHz, IF = 8 mA, VCC = 30 V
10
Rise Time
tR
50
ns
Fall Time
tF
50
ns
Output High Level Common Mode
Transient Immunity
|CMH|
25
35
kV/µs
TA = 25°C,
VCM = 1.5 kV
18
11
Output Low Level Common Mode
Transient Immunity
|CML|
25
35
kV/µs
18
12 Package Characteristics
For each channel unless otherwise specified.
Test
Parameter
Symbol Min. Typ.
Max. Units Conditions
Input-Output Momentary Withstand
Voltage
Fig.
Note
VISO
3750 Vrms
TA = 25°C,
RH < 50% for 1 min.
8,9
Output-Output Momentary Withstand VO-O
Voltage
1500 Vrms
15
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.
-0.5
-1.0
-1.5
-2.0
-25
0
25
50
75
100 125
0.36
0.34
0.32
0.30
-50
TA – TEMPERATURE – °C
Figure 1. VOH vs. temperature.
-25
0
0.42
0.41
0.40
0
25
50
75
100 125
0.465
0.460
0.455
0.450
0.445
0.440
-50
-25
0
25
50
75
100 125
1.0
0.8
0.6
0.4
ICCL
ICCH
75
100 125
TA – TEMPERATURE – °C
Figure 7. ICC vs. temperature.
HCPL-J314 fig 07
ICC – SUPPLY CURRENT – mA
1.2
50
-6
0
0.2
0.4
0.6
IOH – OUTPUT HIGH CURRENT – A
20
15
10
5
0
0
100 200 300 400 500 600 700
IOL - OUTPUT LOW CURRENT - mA
Figure 6. VOL vs. IOL.
1.2
25
-5
HCPL-J314 fig 05
1.4
0
-4
TA – TEMPERATURE – °C
HCPL-J314 fig 04
-25
-3
25
Figure 5. IOL vs. temperature.
0.2
-2
HCPL-J314 fig 03
VOL - OUTPUT LOW VOLTAGE - V
IOL – OUTPUT LOW CURRENT – A
VOL – OUTPUT LOW VOLTAGE – V
0.43
-25
VOH
-1
Figure 3. VOH vs. IOH.
0.470
Figure 4. VOL vs. temperature.
ICC – SUPPLY CURRENT – mA
100 125
0
HCPL-J314 fig 02
TA – TEMPERATURE – °C
75
Figure 2. IOH vs. temperature.
0.44
0
-50
50
TA – TEMPERATURE – °C
HCPL-J314 fig 01
0.39
-50
25
1.0
0.8
0.6
0.4
ICCL
ICCH
0.2
0
10
15
20
25
VCC – SUPPLY VOLTAGE – V
Figure 8. ICC vs. VCC.
HCPL-J314 fig 08
30
IFLH – LOW TO HIGH CURRENT THRESHOLD – mA
-2.5
-50
0.38
(VOH-VCC) – OUTPUT HIGH VOLTAGE DROP – V
IOH – OUTPUT HIGH CURRENT – A
(VOH-VCC) – HIGH OUTPUT VOLTAGE DROP – V
0.40
0
3.5
3.0
2.5
2.0
1.5
-50
-25
0
25
50
75
100 125
TA – TEMPERATURE – °C
Figure 9. IFLH vs. temperature.
HCPL-J314 fig 09
400
300
200
100
0
10
TPLH
TPHL
15
20
25
300
200
100
0
30
500
TP – PROPAGATION DELAY – ns
TP – PROPAGATION DELAY – ns
6
9
Figure 10. Propagation delay vs. VCC.
TP – PROPAGATION DELAY – ns
350
TPLH
TPHL
250
0
50
100
150
200
Rg – SERIES LOAD RESISTANCE – Ω
100
TPLH
0
TPHL
0
20
40
60
25
20
15
10
5
1.6
VF – FORWARD VOLTAGE – V
Figure 16. Input current vs. forward voltage.
1.8
80
Cg – LOAD CAPACITANCE – nF
HCPL-J314 fig 14
IF – FORWARD CURRENT – mA
-25
0
25
50
75
100 125
HCPL-J314 fig 12
200
HCPL-J314 fig 13
HCPL-J314 fig 16
TPHL
Figure 12. Propagation delay vs. temperature.
300
Figure 14. Propagation delay vs. Cg.
1.4
TPLH
35
Figure 13. Propagation delay vs. Rg.
0
1.2
100
TA – TEMPERATURE – °C
400
300
200
HCPL-J314 fig 11
400
10
18
Figure 11. Propagation delay vs. IF.
HCPL-J314 fig 10
TP – PROPAGATION DELAY – ns
15
300
IF – FORWARD LED CURRENT – mA
VCC – SUPPLY VOLTAGE – V
200
12
400
0
-50
VO - OUTPUT VOLTAGE - V
TP – PROPAGATION DELAY – ns
400
100
30
25
20
15
10
5
0
-5
0
1
2
3
4
5
IF - FORWARD LED CURRENT - mA
Figure 15. Transfer characteristics.
6
1
8
0.1 µF
IF = 7 to 16 mA
+
10 KHz –
500 Ω
50% DUTY
CYCLE
2
+
–
7
IF
VCC = 15
to 30 V
tr
tf
VO
3
6
90%
47 Ω
50%
VOUT
3 nF
4
10%
5
tPLH
tPHL
Figure 17. Propagation delay test circuit and waveforms.
VCM
IF
5V
+
–
1
δt
0.1 µF
A
B
δV
8
2
VO
6
4
5
VCC = 30 V
VO
–
Figure 18. CMR test circuit and waveforms.
11
VOH
SWITCH AT A: IF = 10 mA
SWITCH AT B: IF = 0 mA
+
∆t
∆t
+
–
VO
VCM = 1500 V
VCM
0V
7
3
=
VOL
Applications Information
Eliminating Negative IGBT Gate Drive
To keep the IGBT firmly off, the HCPL-J314 has a very low
maximum VOL specification of 1.0 V. Minimizing Rg and
the lead inductance from the HCPL-J314 to the IGBT gate
and emitter (possibly by mounting the HCPL-J314 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 19. Care should be taken with such a
PC board design to avoid routing the IGBT collector or
HCPL-J314
+5 V
1
270 Ω
CONTROL
INPUT
74XXX
OPEN
COLLECTOR
8
0.1 µF
2
7
3
6
4
5
Figure 19. Recommended LED drive and application circuit for HCPL-J314.
12
emitter traces close to the HCPL-J314 input as this can
result in unwanted coupling of transient signals into the
input of HCPL-J314 and degrade performance. (If the
IGBT drain must be routed near the HCPL-J314 input,
then the LED should be reverse biased when in the off
state, to prevent the transient signals coupled from the
IGBT drain from turning on the HCPL-J314.)
+
-
VCC = 15 V
+ HVDC
Rg
Q1
3-PHASE
AC
Q2
- HVDC
Step 1: Calculate Rg minimum from the IOL peak specification. The IGBT and Rg in Figure 19 can be analyzed as
a simple RC circuit with a voltage supplied by the HCPLJ314.
Rg ≥­
VCC – VOL
————
IOLPEAK
24 V – 5 V
=­­­ ————
0.6A
= 32 Ω
The VOL value of 5 V in the previous equation is the VOL
at the peak current of 0.6A. (See Figure 6).
Step 2: Check the HCPL-J314 power dissipation and increase Rg if necessary. The HCPL-J314 total power dissipation (PT ) is equal to the sum of the emitter power (PE)
and the output power (PO).
PT = PE + PO
PE = IF 6 VF 6 Duty Cycle
PO = PO(BIAS) + PO(SWITCHING) = ICC 6 VCC + ESW (Rg,Qg) 6 f
= (ICCBIAS + KICC 6 Qg 6 f) 6 VCC + ESW (Rg,Qg) 6 f
where KICC 6 Qg 6 f is the increase in ICC due to switching and KICC is a constant 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 6 1.8 V 6 0.8 = 14 mW
PO = (3 mA + (0.001 mA/(nC 6 kHz)) 6 20 kHz 6 100 nC) 6
24 V + 0.4 µJ 6 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 over entire operating temperature range.
Since PO for this case is less than PO(MAX), Rg = 32 Ω is all
right for the power dissipation.
13
Esw – ENERGY PER SWITCHING CYCLE – µJ
Selecting the Gate Resistor (Rg)
4.0
Qg = 50 nC
Qg = 100 nC
Qg = 200 nC
Qg = 400 nC
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
20
40
60
80
100
Rg – GATE RESISTANCE – Ω
Figure 20. Energy dissipated in the HCPL-J314 and for
each IGBT switching cycle.
LED Drive Circuit Considerations for Ultra High CMR 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 21. The HCPL-J314
improves 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 22. 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 off ) during common mode transients. For example, the recommended application circuit
(Figure 19), 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.
8
1
CLEDP
2
3
1
7
2
6
CLEDN
4
3
5
8
CLEDP
7
6
CLEDN
4
Figure 21. Optocoupler input to output capacitance
model for unshielded optocouplers.
5
Figure 22. Optocoupler input to output capacitance
model for shielded optocouplers.
HCPL-J314 fig 22
+5 V
8
1
2
+
VSAT
-
CLEDP
7
0.1
µF
+
-
VCC = 18 V
ILEDP
3
6
CLEDN
4
5
SHIELD
Rg
***
***
* THE ARROWS INDICATE THE DIRECTION
OF CURRENT FLOW DURING ÐdVCM/dt.
+ VCM
Figure 23. Equivalent circuit for Figure 17 during common mode transient.
1
8
+5 V
2
Q1
1
8
+5 V
3
CLEDP
CLEDN
7
2
6
3
5
4
CLEDP
CLEDN
7
6
ILEDN
4
SHIELD
Figure 24. Not recommended open collector drive circuit.
14
SHIELD
5
Figure 25. Recommended LED drive circuit for ultra-high CMR
IPM dead time and propagation delay specifications.
CMR with the LED On (CMRH)
IPM Dead Time and Propagation Delay Specifications
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 8 mA provides
adequate margin over the maximum IFigure 26. Minimum
LED Skew for Zero Dead Time.Figure 27. Waveforms for
Dead Time. of 5 mA to achieve 10 kV/µs CMR.
The HCPL-J314 includes a Propagation Delay Difference (PDD) specification intended to help
designers minimize “dead time” in their power
inverter designs. Dead time is the time high and
low side power transistors are off. Any overlap
in Ql and Q2 conduction will result in large currents
flowing through the power devices from the highvoltage 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 off of LED1) so that under
worst-case conditions, transistor Q1 has just turned off
when transistor Q2 turns on, as shown in Figure 26. The
amount of delay necessary to achieve this condition is
equal to the maximum value of the propagation delay
difference specification, PDD max, which is specified
to be 500 ns over the operating temperature range of
-40° to 100°C.
CMR with the LED Off (CMRL)
A high CMR LED drive circuit must keep the LED off (VF
≤ VF(OFF)) during common mode transients. For example, during a -dVCM/dt transient in Figure 23, the current
flowing through CLEDP also flows through the RSAT and
VSAT of the logic gate. As long as the low state voltage
developed across the logic gate is less than VF(OFF) the
LED will remain off and no common mode failure will
occur.
The open collector drive circuit, shown in Figure 24, can
not keep the LED off during a +dVCM/dt transient, since
all the current flowing through CLEDN must be supplied
by the LED, and it is not recommended for applications
requiring ultra high CMR1 performance. The alternative
drive circuit which like the recommended application
circuit (Figure 19), does achieve ultra high CMR performance by shunting the LED in the off state.
Delaying the LED signal by the maximum propagation delay difference 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 difference between the
maximum and minimum propagation delay difference
specification as shown in Figure 27. The maximum
dead time for the HCPL-J314 is 1 µs (= 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.
ILED1
VOUT1
Q1 ON
Q1 OFF
Q2 ON
VOUT2
ILED2
Q2 OFF
tPHL MAX
tPLH MIN
PDD* MAX = (tPHL- tPLH)MAX = tPHL MAX - tPLH MIN
*PDD = PROPAGATION DELAY DIFFERENCE
NOTE: FOR PDD CALCULATIONS THE PROPAGATION DELAYS
ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.
Figure 26. Minimum LED skew for zero dead time.
HCPL-J314 fig 27
ILED1
VOUT1
Q1 ON
Q1 OFF
Q2 ON
VOUT2
Q2 OFF
ILED2
tPHL MIN
tPHL MAX
tPLH
MIN
tPLH MAX
(tPHL-tPLH) MAX
PDD* MAX
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 DIFFERENCE
NOTE: FOR DEAD TIME AND PDD CALCULATIONS ALL PROPAGATION
DELAYS ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS.
Figure 27. Waveforms for dead time.HCPL-J314 fig 28
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Data subject to change. Copyright © 2005-2008 Avago Technologies Limited. All rights reserved. Obsoletes 5989-2942EN
AV02-0155EN - April 9, 2008