2.1 Latch-Up Standard

The current Latch-Up standard, JESD78, stresses pins categorized by type. These types are input, output, bi-directional (I/O), power supply and ground. Input, output and bi-directional pins, in most cases, receive a current stress pulse. The power supply receives an over-voltage stress, a voltage pulse. The pulse widths can be chosen from a range of values but most often in the industry, 2 ms to 10 ms is preferred. The current pulse height typical values are 100 mA while the over-voltage is 1.5 x VMAX (operating). Products requiring clocking or other timing signals can use test vectors in either a Latch-Up tester or an ATE. Timing or pins receiving vectors generally are not stressed since the stress pulse may interfere with the part set-up creating a false failure. Figure 4, Figure 5 and Figure 6 show the stress waveforms from JESD78.

Figure 4. Positive Current Pulse Waveform

Figure 5. Negative Current Pulse Waveform

Figure 6. Over-Voltage Stress Waveform