IEC PAS 60747-17:2011 pdf – Semiconductor devices – Discrete devices- Part 17: Magnetic and capacitive coupler for basic and reinforced isolation.
A production lot is defined here as the number of devices which have been produced using the same production line and production conditions Examples of different package types are:
DIP-4, -6, -8, SOlC-8. etc. Thus, it a manufacturer has five different package types, then 20 samples each would be pulled for this destructive partial discharge test for a total of (5 20 – 100 couplers) per quarter. Multiple channels does not constitute a package type difference. The purpose of this random testing per quarter is to monitor the quality of the manufacturing with respect to selected criteria. The minimum sampling size is n — 80 of which the failures shall be c — 0, i.e. there shall be no failure.
7.4.3 Type Test
Type test has to be performed with the introduction of a new coupler, which differs from already tested couplers in one or more of the following items:
— Package or die materials relevant I or insulation: mold materials, silicone gels, foils. etc.
— Lead frame: if the new lead frame affects the external creepage distance or external clearance or the thermal resistance of the package and thereby P5 or or s are
aftected. — —
— Package or die construction relevant for isolation.
(Examples: change from single mold coplanar to a double mold coplanar package)
Any changes of one or more of those items are considered major changes, which require a
new type test for an existing product.
Type tests shall include at least the following subgroups (7.4,3.1 to, with the
— Zero faIlure must be achieved.
— If one failure occurs out of the 100 devices, further quantities of devices must be subjected to the subgroup (in which the failure occurred), with no more failures.
NOTE Safety Limiting Values 50 T5)
FOr components to provide sate electrical esolat.on, the requirements for satisfactory Isolation have the first pnorlty.
Tile Salely Umiting values to be defined by tile manutacturer for a coupler device are tile input power dissipation (PS ). ,naximum output current (‘s 0) maximum output power dissipation (P5 , or the maximum ambient safety temperature (Ta) that can be Ilowed In the event of a fault or a failure wiIhdbT causing the insulation of the device to breakdown.
The Safely Umiting Values determine the maximum range 01 ioput or output power dissipations allowed over which. although the digital (unction of the isolating elements may be destroyed. the isolation specification of th, device remains Intact. The safety limit temperature (Ts) is tile highest enclosure temperature permitted In the event of a fault,
Tile requirement for isolation remains even when the operation o4 the coupler is no longer In existence due to
external electrical or thermal stress, when toe example
1) The internal digital circuitry becomes faulted due to excessive current or input power.
2) Internal bond wires melt.
3) OperatIon of tile coupler Is impeded by an external heat source (e.g. a resIstor).
The safety limiting values are governed by the materials and circuit desIgn parameters adopted by the manutacturer. and the user must ensure that the safety limiting values are not exceeded, to ensure thai the isolation resistance Or in*ufat ion of tile coupler remaine intact.
Th, user will ensure the safety limiting values are not exceeded through adequate safety arrangements in the circuit design and application conditions of the coupler, e.g.:
a) Current limitation of the lnput’output circuit.
b) Voltage limitation of the ‘nput,outpul circuit,
C) Thermal management of the circuit, which ensures absolute maximum junction temperatures or absolute maximum operating temperature as specified In the manufacturer’s datasheet is not exceeded.
d) The surrounding circuit to be ignition resistant.