50 mA, High Voltage, Micropower Linear Regulator ADP1720 FEATURES TYPICAL APPLICATION CIRCUITS Wide input voltage range: 4 V to 28 V ADP1720 FIXED Maximum output current: 50 mA 1 8 GND GND Low light load current: V = 28V 2 IN GND 7 IN 28 A at 0 A load 1F 3 6 OUT GND 35 A at 100 A load 4 EN GND 5 V = 5V OUT Low shutdown current: 0.7 A 1F Low dropout voltage: 275 mV 50 mA load Initial accuracy: 0.5% Figure 1. ADP1720 with Fixed Output Voltage, 5.0 V Accuracy over line, load, and temperature: 2% Stable with small 1F ceramic output capacitor ADP1720 R2 ADJUSTABLE Fixed 3.3 V and 5.0 V output voltage options 1 ADJ GND 8 R1 Adjustable output voltage option: 1.225 V to 5.0 V V = 12V 2 IN GND 7 IN Current limit and thermal overload protection 1F 3 6 OUT GND Logic controlled enable 4 EN GND 5 V = OUT Space-saving thermally enhanced MSOP package 1.225V(1 + R1/R2) 1F APPLICATIONS Figure 2. ADP1720 with Adjustable Output Voltage, 1.225 V to 5.0 V DC-to-DC post regulation PCMCIA regulation Keep-alive power in portable equipment Industrial applications GENERAL DESCRIPTION The ADP1720 is a high voltage, micropower, low dropout linear The ADP1720 is optimized for stable operation with small 1 F regulator. Operating over a very wide input voltage range of 4 V ceramic output capacitors, allowing for good transient perform- to 28 V, the ADP1720 can provide up to 50 mA of output current. ance while occupying minimal board space. With just 28 A of quiescent supply current and a micropower The ADP1720 operates from 40C to +125C and uses current shutdown mode, this device is ideal for applications that require limit protection and thermal overload protection circuits to low quiescent current. prevent damage to the device in adverse conditions. The ADP1720 is available in fixed output voltages of 3.3 V and Available in a small thermally enhanced MSOP package, the 5.0 V. An adjustable version is also available, which allows the ADP1720 provides a compact solution with low thermal resistance. output to be set anywhere between 1.225 V and 5.0 V. An enable function that allows external circuits to turn on and turn off the ADP1720 output is available. For automatic startup, the enable (EN) pin can be connected directly to the input rail. Rev. A 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 06111-001 06111-002ADP1720 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Performance Characteristics ..............................................7 Applications ....................................................................................... 1 Theory of Operation ...................................................................... 10 Typical Application Circuits ............................................................ 1 Adjustable Output Voltage (ADP1720 Adjustable) ............... 10 General Description ......................................................................... 1 Applications Information .............................................................. 11 Revision History ............................................................................... 2 Capacitor Selection .................................................................... 11 Specif icat ions ..................................................................................... 3 Current Limit and Thermal Overload Protection ................. 11 Absolute Maximum Ratings ............................................................ 5 Thermal Considerations ............................................................ 12 Thermal Resistance ...................................................................... 5 Printed Circuit Board Layout Considerations ....................... 14 ESD Caution .................................................................................. 5 Outline Dimensions ....................................................................... 15 Pin Configurations and Function Descriptions ........................... 6 Ordering Guide .......................................................................... 15 REVISION HISTORY 7/07Rev. 0 to Rev. A Change to Figure 1 ........................................................................... 1 Changes to Table 1 ............................................................................ 3 Changes to Ordering Guide .......................................................... 15 2/07Revision 0: Initial Version Rev. A Page 2 of 16