AM79C02 - AMD

AM79C02 (AM79C02/03/031) Power-On Reset and Power Sequencing

Power-On Reset and Power Sequencing for the Am79C02/03/031 DSLAC™ Devices Application Note The purpose of this application note is to consider the behavior of the Dual Subscriber Line AudioProcessing Circuit (DSLAC™) device on a linecard during power-up. It is necessary to understand the behavior of the DSLAC device during power-up to ensure a successful lin.

Features

Circuit The reset signal is designed to be Low at initial powerup and become High shortly after VCC reaches its normal operating voltage. Assume the VCC rail has been at 0 V for some time so that capacitors C1 and C2 are completely uncharged and then VCC is applied. It can be seen that initially the gate of the n-channel transistor T1 will still have 0 V applied to it (due to the uncharged state of C1) and will therefore be turned off. C2 is also uncharged, but since one plate of this capacitor is now at +5 V, the input to the inverter will also be at +5 V. The output of the inverter will the.