www.ams.com/DC-DC_Step-Up/AS7620

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1 General Description

The AS7620 is an easy-to-use, high-efficiency, high-voltage,

hysteretic step-down DC-DC converter, operating in asynchronous

mode. Its low-power architecture extends hold-up time in battery-

backed and critical applications where maximum up-time over a wide

input supply voltage range is needed, while still providing for high

efficiencies of up to 90% during peak current demands.

Although the AS7620 is optimized for 24V applications found in

industrial and medical systems, its ability to support 100% Duty

Cycle makes the AS7620 ideal for applications demanding maximum

up-time and soft power fail behavior. In combination with low idle

current of only 30µA, on-demand switching reduces operating

current at low load currents.

By selecting an appropriate inductor value, operating current can be

lowered and switching frequencies tuned to certain load conditions.

A pin-strapped current limit input minimizes inductor peak current

and thus inductor size and cost for any given application.

The device further includes output short-circuit protection and

thermal shutdown. In shutdown mode, only 1µA (typ) of current is

consumed.

Figure 1. AS7620 - Block Diagram

2 Key Features

Low quiescent current for efficient partial load operation

Wide Supply Voltage Range, 3.6V to 32V

100% Duty Cycle extends operating range

Pin-programmable cycle-by-cycle current limit

Integrated PMOS eliminates bootstrap capacitor

Resistor-programmable Early Power Fail Warning Input

Power-Good Flag

Thermal Shutdown

Small 4x4mm 12-Lead MLPQ Enhanced Power Package

Specified from -40ºC to +125ºC junction and 85ºC maximum

ambient temperatures

3 Applications

The AS7620 is suitable for Industrial 24VDC applications like PLCs,

robotics; Home Security and Building Control applications; Solid-

state utility meters; Signage and LED column power; and Sensor

interfaces.

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LX

ILIM

PG

PF

VIN

SHDN

FB

VEPF

LDO

Temp

Level

Shifter

Soft-Start

Hysteretic

Controller

AS7620