ANSI SP5.4.1:2017 pdf free download – Transient Latch-up Testing Device Level
ground pin. The common or zero-potential pin(s) of the DUT. NOTE: These pins are generally biased to 0 volts and all measurements are made relative to this reference. maximum operating voltage (maximum V supply ). Value listed in the device data sheets for which the device will still meet all specifications under operating conditions. It is not the same as the absolute maximum voltage allowed without causing permanent damage. maximum stress voltage (MSV). The maximum voltage allowed to be applied to the stressed pin during TLU testing without causing catastrophic damage to the device. NOTE: MSV might depend on the TLU stress pulse width; it can be larger than the absolute maximum rated voltage. nominal supply current (I nom ). The measured DC supply current for each V DD supply. The nominal supply current is in the range of supply currents possible under all normal operating states. preconditioning. The process of setting the input states of a device and applying appropriate electrical signals until a particular desired functional state is achieved. signal pins. Any connected pin that does not supply power or ground to the component. signaling (transient) latch-up. Latch-up phenomenon which occurs between any signal pin (input, output, I/O) and any other pin; for example, neighboring inputs, outputs, I/O, VSS, or VDD. The signaling latch-up can be triggered at the pin under stress or any other pin which is powered in the chip.
7.1 Schematic of the TLU Characterization Set-up
In its most simple implementation, a TLU characterization set-up comprises a pulse source which generates the transient trigger pulse and a DC voltage/current source which supplies the DUT. In typical applications, the set-up is much more complex. Typically, several DC voltage sources are required to power-up the DUT. Voltage and current probes are required to capture the voltage and current stress parameters, which are recorded at an oscilloscope. Decoupling devices protect the DC sources from damage due to the TLU trigger. The DC currents and voltages should be measured by appropriate DC voltage/current meters.
The connection of the devices to the DUT depends on the type of latch-up which should be triggered. In general, for TLU three essentially different tests can be carried out:
1 . Overvoltage TLU test of a power supply.
2. Injection of current to signal pins and monitoring the power supplies.
3. Injection of current to signal pins and monitoring the pin current. This test is part of an extended characterization methodology.