Harman Kardon AVR 171/230, Руководство по обслуживанию

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ESMT/EMP
EML3418
Elite Semiconductor Memory Technology Inc./
Elite Micropower Inc.
Publication Date: Jan. 2011
Revision: 2.3 1/17
1.3MHz 2A, Synchronous Step-Down Regulator
General Description
EML3418 is designed with high efficiency step
down DC/DC converter for portable devices
applications. It features with extreme low
quiescent current with no load which is the best
fit for extending battery life during the standby
mode. The device operates from 2.5V to 5.5V
input voltage and up to 2.0A output current
capability. High 1.3MHz internal frequency
makes small surface mount inductors and
capacitors possible and reduces overall PCB
board space. Further, build-in synchronous
switch makes external Schottky diode is no
longer needed and efficiency is improved.
EML3418 is designed base on pulse width
modulation (PWM) for low output voltage ripple
and fixed frequency noise, low dropout mode
provides 100% duty cycle operation. Low
reference voltage is designed for achieving
regulated output down to 0.6V.
The device is available in an adjustable version
for TDFN-8 and SOP-8FD package.
Features
„
Achieve 95% efficiency
„
Input Voltage : 2.5V to 5.5V
„
Output Current up to 2A
„
Reference voltage 0.6V
„
Quiescent Current 240
μ
A with No
Switching
„
Internal switching frequency 1.3MHz
„
No Schottky Diode needed
„
Low Dropout Operation: 100% Duty Cycle
„
Shutdown current < 1
μ
A
„
Excellent Line and Load Transient
Response
„
Over-current and Over-temperature
Protection
Applications
„
Blue-Tooth devices
„
Cellular and Smart Phones
„
Personal multi-media Player (PMP)
„
Wireless networking
„
Digital Still Cameras
„
Portable applications
Typical Application (adjustable)
Fig. 1
Fig. 2
Harman Kardon AVR 171 Service Manual
Page 83 of 174