NCP1508 Datasheet, PDF (1/15 Pages) ON Semiconductor – Up to 500 mA, 1 MHz, High Efficiency Synchronous Step−Down DC−DC Converter in DFN Package

NCP1508
Up to 500 mA, 1 MHz, High
Efficiency Synchronous
Step−Down DC−DC
Converter in DFN Package
The NCP1508 step−down PWM DC−DC converter is optimized
for portable applications powered from 1−cell Li−ion or 3 cell
Alkaline/NiCd/NiMH batteries. This DC−DC converter utilizes a
current−mode control architecture for easy compensation and better
line regulation. It also uses synchronous rectification to increase
efficiency and reduce external part count. The NCP1508 optimizes
efficiency in light load conditions when switched from a normal
PWM mode to a “pulsed switching” mode. The device also has a
built−in 1 MHz (nominal) oscillator for the PWM circuitry, or it can
be synchronized to an external 500 kHz to 1000 kHz clock signal.
Finally, it includes an integrated soft−start, cycle−by−cycle current
limiting, and thermal shutdown protection. The NCP1508 is
available in a space saving, low profile 3x3 mm 10 pin DFN package.
Features
• High Efficiency:
93% for 1.89 V Output at 3.6 V Input and 125 mA Load Current
91% for 1.89 V Output at 3.6 V Input and 300 mA Load Current
• Digital Programmable Output Voltages: 1.0, 1.3, 1.5 or 1.89 V
• Output Current up to 500 mA at V_in = 3.6 V
• Low Quiescent Current of 14 mA in Pulsed Switching Mode
• Low 0.2 mA Shutdown Current
• −30°C to 85°C Operation Temperature
• Low Profile DFN Package
• Pb−Free Package is Available
Application
• Cellular Phones, Smart Phones and PDAs
• Digital Still Cameras
• MP3 Players and Portable Audio Systems
100
• Wireless and DSL Modems
90
• Portable Equipment
80
V_in
2.7 V − 5.2 V
5 _VCC
C_in
4 _VCCP
10 mH _{9 SHD}
LX ^{3 6.8 mH}
FB ⁶
V_out
C_out
22 mH
70
60
50
40
CB1 ⁸ CB0 and CB1
10 _{SYNC CB0} 7 _{Control Input}
30
20
GNDA GNDP
10
0
0.001
Figure 1. Typical Application Circuit
http://onsemi.com
MARKING
DIAGRAM
1
10 PIN DFN
1508
MN SUFFIX
ALYW
1
CASE 485C
1508 = Specific Device Code
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
ORDERING INFORMATION
Device
Package
Shipping†
NCP1508MNR2 10 Pin DFN 3000 Tape & Reel
NCP1508MNR2G 10 Pin DFN 3000 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.
Pulsed Mode
PWM Mode
V_in = 3.6 V
V_out = 1.5 V
0.01
0.1
1
10
I_out (mA)
100 1000
Figure 2. Efficiency vs. Output Current
© Semiconductor Components I1dustries, LLC, 2006
1
July, 2006 − Rev. 1
Publication Order Number:
NCP1508/D