LM3477A

The LM3477A is a high-side N-channel MOSFET switching regulator controller.It can be used into pologies requiring a high side MOSFET such as buck,inverting(buck-boost) and zetare gulators.The LM3477/A's internal push pull driver allows compatibility with awide range of MOSFETs.This,the wide input voltage range,use of discrete power components and adjust able current limit allows the LM3477/ A to beopti- mized for a wide variety of applications.

The LM3477A usesa highs witch ingfre quency of 500kHz to reduce the over all solution size.Current-mode controlre- quires only asing leresistor and capacitor for frequency compensation.The current modearchi tecture also yields superior line and load regulation and cycle-by-cycle current limiting.A 5µA shutdown state can be used for power sav-ing sand for power supply sequencing.Other feature sin-clude internal soft-start and output over voltage protection. The internal soft-start reduces in rush current.Over voltage protection is a safet feature to ensure that the output volt-age stays with in regulation.

The LM3477A is similar to the LM3477.The primary differ-ence between the two is the point at which the device transitions in to hysteretic mode.The hysteretic thres hold of the LM3477A is one-third of the LM3477.