NCP1421 Datasheet, PDF (1/14 Pages) ON Semiconductor – 600 mA Sync-Rect PFM Step-Up DC-DC Converter Step-Up DC-DC Converter with True-Cutoff and Ring-Killer

NCP1421
600 mA Sync−Rect PFM
Step−Up DC−DC Converter
with True−Cutoff and
Ring−Killer
NCP1421 is a monolithic micropower high−frequency step−up
switching converter IC specially designed for battery−operated
hand−held electronic products up to 600 mA loading. It integrates
Sync−Rect to improve efficiency and to eliminate the external
Schottky Diode. High switching frequency (up to 1.2 MHz) allows
for a low profile, small−sized inductor and output capacitor to be
used. When the device is disabled, the internal conduction path from
LX or BAT to OUT is fully blocked and the OUT pin is isolated from
the battery. This True−Cutoff function reduces the shutdown current
to typically only 50 nA. Ring−Killer is also integrated to eliminate
the high−frequency ringing in discontinuous conduction mode. In
addition to the above, Low−Battery Detector, Logic−Controlled
Shutdown, Cycle−by−Cycle Current Limit and Thermal Shutdown
provide value−added features for various battery−operated
applications. With all these functions on, the quiescent supply
current is typically only 8.5 mA. This device is available in the
compact and low profile Micro8t package.
Features
• Pb−Free Package is Available
• High Efficiency: 94% for 3.3 V Output at 200 mA from 2.5 V Input
88% for 3.3 V Output at 500 mA from 2.5 V Input
• High Switching Frequency, up to 1.2 MHz (not hitting current limit)
• Output Current up to 600 mA at V_IN = 2.5 V and V_OUT = 3.3 V
• True−Cutoff Function Reduces Device Shutdown Current to
typically 50 nA
• Anti−Ringing Ring−Killer for Discontinuous Conduction Mode
• High Accuracy Reference Output, 1.20 V $1.5%, can Supply
2.5 mA Loading Current when V_OUT > 3.3 V
• Low Quiescent Current of 8.5 mA
• Integrated Low−Battery Detector
• Open Drain Low−Battery Detector Output
• 1.0 V Startup at No Load Guaranteed
• Output Voltage from 1.5 V to 5.0 V Adjustable
• 1.5 A Cycle−by−Cycle Current Limit
• Multi−function Logic−Controlled Shutdown Pin
• On Chip Thermal Shutdown with Hysteresis
Typical Applications
• Personal Digital Assistants (PDA)
• Handheld Digital Audio Products
• Camcorders and Digital Still Cameras
• Hand−held Instruments
• Conversion from one to two Alkaline, NiMH, NiCd Battery Cells to
3.0−5.0 V or one Lithium−ion cells to 5.0 V
• White LED Flash for Digital Cameras
http://onsemi.com
8
1
MARKING
DIAGRAM
Micro8
DM SUFFIX
CASE 846A
1421
AYW
1421
A
Y
W
= Device Code
= Assembly Location
= Year
= Work Week
PIN CONNECTIONS
FB 1
LBI/EN ₂
LBO 3
REF 4
8 OUT
7 LX
6 GND
5 BAT
(Top View)
ORDERING INFORMATION
Device
Package
Shipping†
NCP1421DMR2
Micro8 4000 Tape & Reel
NCP1421DMR2G Micro8 4000 Tape & Reel
(Pb−Free)
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
© Semiconductor Components Industries, LLC, 2004
1
October, 2004 − Rev. 6
Publication Order Number:
NCP1421/D