ams Datasheet

Page 7

[v1-01] 2015-May-22

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AS1383 − Detailed Descriptions

The AS1383 can operate from 2.7V to 5.5V and features fixed

frequency (3.5MHz) and current mode PWM control for

exceptional line- and load regulation. With low RDS(ON) and

gate charge internal NMOS and PMOS switches, the device

maintains high-efficiency from light to heavy loads.

Modern portable devices frequently spend extended time in

low-power or standby modes, switching to high power-drain

only when certain functions are enabled. The AS1383 is ideal

for portable devices since it maintain high-power conversion

efficiency over a wide output power range, thus increasing

battery life in these types of devices.

In addition to high-efficiency at moderate and heavy loads, the

AS1383 includes an automatic powersave mode that improves

efficiency of the power converter at light loads. The powersave

mode is initiated if the output load current falls below a factory

programmed threshold.

Figure 8:

AS1383 Block Diagram

Detailed Descriptions

PWM

Control

Sync Drive

Control

3.5MHz Ramp

Generator

Slope

Compensation

Shu tdown

Control

Powersave

Operation

Control

1.25V

Ref

gm Error

Amp

Σ

PWM

Comp

-

Shutdown

Current

Sense

Powersave

GND

SW

VIN

EN

FB

VOUT

10uF

2.7V to 5.5V

L1

1uH

On

Off

2.7V – 5.0V

0.25Ω

0.35Ω

AS1383

4.7uF