NCP1550SN18T1 Datasheet, PDF (1/18 Pages) ON Semiconductor – 600 kHz PWM/PFM Step-Down DC-DC Controller

NCP1550
600 kHz PWM/PFM
Step−Down DC−DC
Controller
The NCP1550 is a monolithic micropower high frequency
voltage mode step−down controller IC, specially designed for battery
operated hand−held electronic products. With appropriate external
P−type MOSFET, the device can provide up to 2.0 A loading
current with high conversion efficiency. The device operates in
Constant−Frequency PWM mode at normal operation, that ensures
low output ripple noise, and which will automatically switch to PFM
mode at low output loads for higher efficiency. Additionally,
value−added features of Chip Enable to reduce IC Off−State current
and integrated feedback resistor network, make it the best choice for
portable applications. The device is designed to operate for voltage
regulation with minimum external components and board space. This
device is available in a TSOP−5 package with six standard output
voltage options.
Features
• Pb−Free Packages are Available
• High Efficiency 92%, Typical
• Low Quiescent Bias Current of 50 mA (Typical at PFM Mode with
No Load)
• Output Voltage Options from 1.8 V to 3.3 V with High Accuracy
$2.0%
• Low Output Voltage Ripple, 50 mV, Typical
• PWM Switching Frequency at 600 kHz
• Automatic PWM/PFM Switchover at Light Load Condition
• Very Low Dropout Operation, 100% Max. Duty Cycle
• Chip Enable Pin with On−Chip 150 nA Pullup Current Source
• Low Shutdown Current, 0.3 mA, Typical
• Input Voltage Range from 2.45 V to 5.5 V
• Built−in Soft−Start
• Internal Undervoltage Lockout (UVLO) Protection
• Low Profile and Minimum External Components
• Micro Miniature TSOP−5 Package
Typical Applications
• Personal Digital Assistant (PDA)
• Camcorders and Digital Still Camera
• Hand−Held Instrument
• Distributed Power System
• Computer Peripheral
• Conversion from Four NiMH or NiCd or One Lithium−ion Cells to
3.3 V/1.8 V
http://onsemi.com
5
1
MARKING
DIAGRAM
TSOP−5
SN SUFFIX
CASE 483
xxxYW
xxx = Device Code
Y = Year
W = Work Week
PIN CONNECTIONS
CE ₁
5 ^VIN
GND 2
V_{OUT 3}
4 EXT
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 16 of this data sheet.
© Semiconductor Components Industries, LLC, 2004
1
September, 2004 − Rev. 6
Publication Order Number:
NCP1550/D