Compact, 800 mA, 3 MHz,
Step-Down DC-to-DC Converter
ADP2138/ADP2139
GENERAL DESCRIPTION
FEATURES
Input voltage: 2.3 V to 5.5 V
Peak efficiency: 95%
3 MHz fixed frequency operation
Typical quiescent current: 24 μA
The ADP2138 and ADP2139 are high efficiency, low quiescent
current, synchronous step-down dc-to-dc converters. The
ADP2139 has the additional feature of an internal discharge
switch. The total solution requires only three tiny external
components. When the MODE pin is set high, the buck
regulator operates in forced PWM mode, which provides low
peak-to-peak ripple for power supply noise sensitive loads at
the expense of light load efficiency. When the MODE pin is set
low, the buck regulator automatically switches operating modes,
depending on the load current level. At higher output loads, the
buck regulator operates in PWM mode. When the load current
falls below a predefined threshold, the regulator operates in power
save mode (PSM), improving light load efficiency.
Very small solution size
Fast load and line transient response
100% duty cycle low dropout mode
Internal synchronous rectifier, compensation, and soft start
Current overload and thermal shutdown protections
Ultralow shutdown current: 0.2 μA (typical)
Forced PWM and automatic PWM/PSM modes
APPLICATIONS
PDAs and palmtop computers
Wireless handsets
Digital audio, portable media players
Digital cameras, GPS navigation units
The ADP2138/ADP2139 operate on input voltages of 2.3 V to
5.5 V, which allows for single lithium or lithium polymer cell,
multiple alkaline or NiMH cell, PCMCIA, USB, and other
standard power sources. The maximum load current of 800 mA
is achievable across the input voltage range.
The ADP2138/ADP2139 are available in fixed output voltages of
3.3 V, 3.0 V, 2.8 V, 2.5 V, 1.8 V, 1.5 V, 1.2 V, 1.0 V, and 0.8 V. All
versions include an internal power switch and synchronous rect-
ifier for minimal external part count and high efficiency. The
ADP2138/ADP2139 have internal soft start and they are internally
compensated. During logic controlled shutdown, the input is
disconnected from the output and the ADP2138/ADP2139
draw 0.2 μA (typical) from the input source.
Other key features include undervoltage lockout to prevent deep
battery discharge, and soft start to prevent input current over-
shoot at startup. The ADP2138/ADP2139 are available in a 6-ball
wafer level chip scale package (WLCSP).
TYPICAL APPLICATIONS CIRCUIT
1.0µH
V
OUT
2.3V TO 5.5V
VIN
SW
4.7µF
4.7µF
ADP2138/
ADP2139
ON
EN
VOUT
OFF
FORCE
PWM
MODE
AUTO
GND
Figure 1.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2011 Analog Devices, Inc. All rights reserved.
5秒后页面跳转
全球首块英伟达H200交付 黄仁勋“送货上门”
常用8脚开关电源芯片型号大全
74HC04芯片引脚图及功能、应用电路图讲解
CR6842芯片参数、引脚配置、应用电路图详解
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
