TLE 7276

Data Sheet

9

Rev. 1.11, 2010-11-22

influences from load surges to the voltage levels. This one can either be an aluminum

electrolytic capacitor or a tantalum capacitor following the application requirements.

A general recommendation is to keep the drop over the equivalent serial resistor (ESR)

together with the discharge of the blocking capacitor below the allowed Headroom of

Since the regulator output current roughly rises linearly with time the discharge of the

capacitor can be calculated as follows:

The drop across the ESR calculates as:

To prevent a reset the following relationship must be fullfilled:

22µF and a typical regulator reaction time under normal operating conditions of dt ~

25µs and for special dynamic load conditions, such as load step from very low base

load, a reaction time of dt ~ 75µs.

So for the ESR we can allow

The permissible ESR becomes:

During design-in of the TLE7469 product family, special care needs to be taken with

regards to the regulators reaction time to sudden load current changes starting from very

low pre-load as well as cyclic load changes. The application note “TLE7x Voltage

Regulators - Application Note about Transient Response at ultra low quiescent current

Voltage Regulators” (see 3_cip05405.pdf) gives important hints for successful design-in

of the Voltage Regulators of the TLE7x family.