* ISO 10605 ed.2 test standard is also described after the description on IEC 61000-4-2
The international immunity test standard which applies to electronic equipment against ESD generated directly from a human body or near metal objects in condition chemical fiber carpets or clothings are used in low hhumidity relatively. This standard assumes cases an charged human body discharges to electonic equipment and testing with the circuit to simulate current waveform generated in such conditions.
discharge current waveform and its characteristics
It is necessary to leave equipment brought in from different climatic conditions fully before performing the test. Also, in order to stabilize the discharging condition certainly, it is necessary to fix the climatic conditions in the test room. Fulfillment of the conditions listed in following table must be required to perform testing in conformance with IEC 61000-4-2.
Direct discharge test: Contact discharge (at 1 second interval ) and air discharge
Indirect discharge test: Discharge to VCP and HCP
At least 10 single discharges shall be applied at 1 second or linger interval in both positive and negative polarities.
* A preliminary test which discharges 20 times or more per second may be done in order to select the points to which single discharges should be applied.
The tests results are classified into following 4 patterns according to specifications of EUT and operating conditions.
1. Normal operation within the tolerance of the spefication
2. Temporary degradation or loss in the operation or the function which is able to be revocered by a self-recovery function
3. Temporary degradation or loss in the operation or the funcition which needs to be recovered by user intervention or reset in the system
4. Damage of the system (parts) or software, and unrecoverable degradation in the function due to loss of the data.
Generally, as far as the EUT is immune to the ESD during testing and it satisfies the functional requirements according to the product sepcification after testing, the test result can be perceived as "Pass". The test report shall contain the test conditions and the result.
Note: This test procedure and test set-up are extracted from IEC 61000-4-2.
Electrostatic discharges which are generated both in vehicles and while we get on and off there can be factors to cause malfunction of the electrical devices and components. Nowadays, more attention has been paid, as vehicles install more and more electronic devices and components. This standard provides that static electricity is discharged to the electronic devices or equipment from the charged human body and tests are simulated by electrical circuit to reproduce the electric current waveform at the discharge.
In addition to procedures for the immunity tests and evaluations in state that the electronic devices or equipment work while the vehicle is driving, also the standard provides tests procedures to evaluate the immunity of the each module against simulated human discharges during the assembly process or in servicing.
The following tests level are reference. The categories are classified according to functional importance of the electronics devices/components.
Following specifications must be satisfied with the simulator for the test.
Following discharges characteristics should be verified.
The waveform shall be verified with an osilloscope whose bandwidth is 1GHz or more in a Faraday cage or with a 1.2m x 1.2m metallic board mouting an ESD current target in the center of the cage or the board. The discharge electrode (Discharge tip of the gun) shall be touched onto the target and the discharge mode shall be set at the contact discharge mode. The discharge return cable shall be turned up the center of the length and connected to vertically 0.5m under the target on surface of the Faraday cage or board.
For testing powered DUT immunity to direct ESD - contact discharge and air discharge -
For testing powered DUT immunity to indirect ESD
For testing (unpowered) packaging and handling ESD sensitivity
Vehicle test - Internal and external points
Optional test set-up and procedure for electronic modules (powered-up test)
- Direct and indirect discharge -