Introduction:

Nowadays, many digital isolator products are based on IEC60664-1\ DIN EN IEC 60747-17 (VDE 0884-17)\UL1577 to do the insulation certification test, the following we excerpted some of the common digital isolator products on the market parameter table, for customers to refer to and design their own products should be completed which insulation test items and test methods.

Overall all test items and test methods are selected based on the certification standard, so we should first select the test standard and then select the test items.

Insulation test standards for common digital isolator products:

IEC60664-1 Insulation test items and test methods:

“Reminder: swipe tables left and right”
Test Item Abbreviations
Test Item Name
Test Methods
Test value (1)
unit (of measure)
CLR
External clearance (1)
Spatial distance from 1st lateral to 2nd lateral
>4mm
mm
CPG
External creepage distance(1)
Package surface distance from primary side to secondary side
>4mm
mm
DTI
Insulation penetration distance
Minimum internal clearance
>17μm
μm
CTI
Comparison of Leakage Trace Index
IEC 60112
>600V
material group
Conforms to IEC 60664-1
Ⅰ
Overpressure classification
Rated mains voltage ≤ 150 Vrms
Ⅰ-Ⅳ
Rated mains voltage ≤ 300 Vrms
Ⅰ-Ⅲ
Rated mains voltage ≤ 600 Vrms
inapplicable
Rated mains voltage ≤ 1000 Vrms
inapplicable
“Reminder: swipe tables left and right”

(1), the listed test value is only a common indicator, the specific value depends on the chip package type, different packages are different indicators.

DIN EN IEC 60747-17 (VDE 0884-17) Insulation test items and test methods:

We have already covered this standard in detail in another post:Certified Test Programs for Digital Isolators and OptocouplersThe

Suitability: This digital isolator is only suitable for safe electrical insulation within the safety ratings. Compliance with safety ratings should be ensured with the aid of suitable protective circuitry.

“Reminder: swipe tables left and right”
Test Item Abbreviations
Test Item Name
Test Methods
Test value (1)
unit (of measure)
VIORM
Maximum Repeated Peak Isolation Voltage
AC Voltage (Bipolar)
707 V
Vpk
VIOWM
Maximum isolated operating voltage
AC voltage (sine wave); time-dependent dielectric breakdown (TDDB) test
500 V
Vrms
VIOTM
Maximum transient isolation voltage
VTEST = VIOTM, t = 60 seconds (qualification test)
VTEST = 1.2 x ViOTM, t = 1 second (100% production test)
4243 V
Vpk
VIMP
Maximum pulse voltage(3)
1.2/50μs surge waveform according to IEC 62368-1, tested in air
5000 V
Vpk
VIOSM
Maximum surge isolation voltage(4)
VIOSM≥1.3× Vimp; 1.2/50μs surge waveform according to IEC 62368-1. tested in oil (qualification test)
10400 V
Vpk
Qpd
Partial discharges (5)
(apparent charge)
Method a, input/output safety test subgroup 2/3 after Vini = VIOTM, Tini = 60 s; Vpd(m) = 1.2 × VIORM, Tm = 10 s
≤5
pC (piku)
Method a, after environmental test subgroup 1, Vini = VIOTM, Tini = 60 s; Vpd(m) = 1.6 × VIORM, Tm = 10 s
≤5
pC (piku)
Method b, conventional test (100% production test), Vini = 1.2 × VIOTM, Tini = 1 sec;
Vpd(m) = 1.875 x VIORM, Tm = 1 s (method b1)
Vpd(m) = Vini, Tm= Tini= 60 seconds (method b2).
≤5
pC (piku)
CIO
Barrier capacitor, input to output (6)
VIO = 0.4 × sin(2 π ft), f = 1MHz
≈1.1
pF
RIO
/
Isolation Resistors, Input to Output (6)
VIO = 500V, Ta = 25°C
>10^12
Ω
VIO=500V, 100℃≤Ta≤125℃
>10^11
Ω
VIO = 500V, Ts = 150°C
>10^9
Ω
/
Contamination level
/
2
/
/
Climate category
/
40, 125, 21
/
“Reminder: swipe tables left and right”

(1) The creepage distances and clearances shall meet the requirements in the application-specific equipment isolation standards. Care should be taken to maintain the board design creepage distance and clearance so that the mounting pads of the isolators on the printed circuit board do not result in a shortening of this distance. Under certain circumstances, the creepage distances and clearances on the printed circuit board become equal. Insertion of a bevel or rib on the printed circuit board or simultaneous application of a

These two technologies can help improve these specifications.

(3), test in air to determine the surge immunity of the package.

(4), testing in oil to determine the inherent surge immunity of the barrier.

(5), the apparent charge is the electrical discharge caused by partial discharge (pd); we recommend the use ofHT-9464M Device Measurement.

(6), all pins on each side of the isolation layer are connected together to form a two-pin device.

UL 1577 Insulation test items and test methods:

“Reminder: swipe tables left and right”
Test Item Abbreviations
Test Item Name
Test Methods
Test value (1)
unit (of measure)
VISO
Withstand isolation voltage
Vtest = Viso, t = 60 seconds (qualification test); Vtest = 1.2 × Viso, t = 1 second (100% production test)
3000 V
Vrms
“Reminder: swipe tables left and right”

Note: For sine wave signals, the RMS value is equal to the peak value divided by the root sign 2; the peak value = RMS * 1.414; and the peak-to-peak value is equal to twice the peak value.

The above is a list of three common standards for insulation certification test items for digital isolator products, and of course there are other test standards such as “What standards to look for in an optocoupler or digital isolator for safe electrical isolation”，“What isolation safety approvals are required for digital isolators or optocoupler chips”。

Test specifications are determined based on the product package:

In the actual digital isolator certification process, we not only pay attention to the test standards, but also according to different product package specifications, as well as the certification of the country category to determine the different digital isolators need to do what insulation test items, as well as the need to do what kind of voltage level.

Note: The following table (DBQ, DW lamps are product package specifications)

“Reminder: swipe tables left and right”
Type of country of accreditation
VDE certification
CSA certification
UL listed
CQC certification
TUV Certification
test standard
DIN EN IEC 60747-17 (VDE 0884-17)
IEC
62368-1 and IEC 60601-1
UL 1577
GB 4943.1
EN 61010-1 and EN
62368-1
Certification Requirements
Reinforced insulation; maximum transient isolation voltages, 8000 VPK (DW-16) and 4242 VPK (DBQ-16); maximum repetitive peak isolation voltages, 2121 VPK (DW-16) and 566 VPK (DBQ-16); maximum inrush isolation voltages, 12800 VPK (DW-16) and 10000 VPK (DBQ-16)
800 VRMS (DW-16) and 370 VRMS (DBQ-16) Maximum Operating Voltage (Pollution Class 2, Material Group I); DW-16: Maximum Operating Voltage Certification 250 VRMS per 2 MOPP (Measures of Protection for Patients) per CSA 60601-1 and IEC 60601-1
DW-16: single heavy protection, 5000 VRMS; DBQ-16: single heavy protection, 3000 VRMS
DW-16: reinforced insulation, altitude ≤ 5000 m, tropical climate, max. operating voltage 700 VRMS;
DBQ-16: Basic insulation, altitude ≤ 5000 m, tropical climate, max. operating voltage 400 VRMS
5000 VRMS reinforced insulation according to EN 61010-1 for operating voltages up to 600 VRMS (DW-16) and 300 VRMS (DBQ-16) 5000 VRMS reinforced insulation according to EN 62368-1 for operating voltages up to 800 VRMS (DW-16) and 370 VRMS (DBQ-16)
“Reminder: swipe tables left and right”

As can be seen from the above table, the product needs to be certified by which country, it determines the subsequent basis of standards and certification requirements, but also with the product package has a relationship, so only this article for the majority of customers to provide a reference to the specific test items and indicators still need to be confirmed by the customer themselves.