TPS62A01A: Slow down the EN signal

Hello Ryu,

thanks for reaching out in E2E.

It is OK to delay the enabling with an R/C circuit. Please be aware that the EN threshold can vary from device to device. If the EN ramp is slow then this can lead to timing variation between devices. Devices with so called Precise Enable feature (i.e. TPS628501 or TPS628511) have a trimmed EN threshold, which allows a better timing accuracy when using an R/C filter.

Anyway, the hysteresis of the EN pin of the TPS62A01A is typically 140mV.

The given threshold limits of minimum 1.2V and maximum 0.4V can be understood as the device variation worst cases. Means in turn, when applying an EN voltage above 1.2V it will for sure enable all devices, even those with the highest threshold in the statistical distribution. Similarly for the low level, an EN voltage below 0.4V is save to disable all devices in the given statistical distribution.

Best regards,

Andreas.

Hello Ryu,

The higher 1.2V limit is stated as a minimum, because you have to apply a minimum of 1.2V signal voltage (or higher) to the EN pin to enable the device for sure.

The actual rising enable threshold is located between 0.4V and 1.2V. The falling threshold is also located between 0.4V and 1.2V, but it is located ca. 140mV lower than the rising threshold due to the hysteresis. Both thresholds are forming statistical distributions when looking at a huge number of devices. The datasheet limits are specifying the required operating conditions. Means, voltage above 1.2V will be safely located above the rising threshold distribution and enabling for sure, and voltages below 0.4V will be safely located below the falling distribution and disabling all devices for sure.

Here is a quick drawing for illustrating the behavior in general but not in accurate numbers:

Best regards,

Andreas.