SN74AHCT126-Q1: SN74AHCT126-Q1，Effect of overcurrent use on service life

Where exactly does this current flow? Please show the schematic.

1.Output current from the chip side

2.The schematic is simplified as follows：

Thank you for your reply, we will choose to increase the current resistance. Based on our current current state, can you provide an assessment of the lifetime of the device?

The current in the manual is DC current, and it appears as pulse current in our application, whether the device can withstand pulse current better. If it's based on the magnitude and pulse width of our current pulse current, as well as the number of pulses per unit of time, please evaluate the device.here will be a current of 120mA with a pulse width of 1uS when it is powered on. Then when it is working normally, there will be 10 times in 1S with 35mA & pulse width of 1uS. 

Hi sir

Question 1: In order to ensure the life of the IC, is it safe to limit the current to less than 20mA?
Question 2: We previously encountered a maximum pulse current of 130mA. If the pulse width is controlled at the 200nS level, can the chip be considered safe?
Question 3: The VOH and VOL voltages in the chip were tested at 50mA, which is greater than the 25mA required by the manual. Does this mean that it is OK to exceed 25mA for a short time?

Hello Expert,

The customer's IOUT is a pulse wave not a continue wave. Do you have SOA curve or pulse power consumption wave for them?

Best regards,

Wenting 

The limit must not be exceeded for any amount of time.

Hello Expert,

We look at the test data of the chip and find that its output waveform edge is 1nS (The minimum time for 50% of the input end and 50% of the output end is 1nS. It can be known that the time for the output voltage waveform from 0 to 90% is less than 1nS.)when the load capacitance is 50pF. According to the calculation, it can be known that the pulse current is 250mA.I=C*du/dt=50pF*5V/1nS=250mA

For loads up to about 50 pF, this is indeed allowed. But not for anything larger.

When we test the load of 50pF, the output current is 250mA in pulse. Does it mean that the chip can accept 250mA pulse current?

It can accept whatever current happens with a 50 pF load. It cannot accept a load of more than 25 mA in any other circumstances.

Hi team

The latest manual clearly states that the output can carry a 50pF capacitor, which must have a 250mA current. The limit capacitance parameter provided by the manual has exceeded the current value required by the manual itself, and the manual is contradictory. If we follow the 50pF load in the manual, the current can support 250mA.
So is the manual wrong, or do we need to believe the value of the 50pF load?