NCP6361 Datasheet, PDF (1/20 Pages) ON Semiconductor – Buck Converter with Bypass Mode for RF Power Amplifiers

NCP6361
Buck Converter with
Bypass Mode for RF Power
Amplifiers
The NCP6361, a PWM synchronous step−down DC−to−DC
converter, is optimized for supplying RF Power Amplifiers (PAs) used
in 3G/4G wireless systems (Mobile / Smart Phones, Tablets,…)
powered by single−cell Lithium−Ion batteries. The device is able to
deliver up to 2 A current in bypass mode and 800 mA in buck mode.
The output voltage is monitorable from 0.4 V to 3.5 V by an analog
control pin VCON. The analog control allows dynamically optimizing
the RF Power Amplifier’s efficiency through the monitoring of the PA
output power. With an improved overall system efficiency the
communication time and phone autonomy can be consequently
increased. At light load for optimizing the DC−to−DC converter
efficiency, the NCP6361 enters automatically in PFM mode and
operates in a slower switching frequency. The NCP6361 enters in
bypass mode when the desired output voltage becomes close to the
input voltage (e.g.: low battery conditions). The device operates at
3.429 MHz or 6 MHz switching frequency. This way the system
tuning can focus respectively either on a better efficiency (3.249 MHz)
or on employing smaller value inductor and capacitors (6 MHz).
Synchronous rectification and automatic PFM / PWM / By−Pass
operating mode transitions improve overall solution efficiency. The
NCP6361 has two versions: NCP6361A and NCP6361B. Version B
has a spread spectrum function for low EMI operation. The NCP6361
is available in a space saving, low profile 1.36 x 1.22 mm CSP−9
package.
http://onsemi.com
MARKING
DIAGRAM
WLCSP9
CASE 567GM
6361x
ALYWW
G
6361x = Specific Device Code
x = A or B
A = Assembly Location
L = Wafer Lot
Y = Year
WW = Work Week
G = Pb−Free Package
ORDERING INFORMATION
See detailed ordering, marking and shipping information on
page 19 of this data sheet.
Features
• Input Voltage from 2.5 V to 5.5 V for Battery Powered
Applications
• Adjustable Output Voltage (0.4 V to 3.50 V)
• 3.429 / 6 MHz Selectable Switching Frequency
• Uses 470 nH Inductor and 4.7 mF Capacitor for
Optimized Footprint and Solution Thickness
• PFM /PWM/Bypass Automatic Mode Change for High
Efficiency
• Low 45 mA Quiescent Current
• Thermal Protections to Avoid Damage of the IC
• Small 1.36 x 1.22 mm / 0.4 mm Pitch CSP Package
• This is a Pb−Free Device
Typical Applications
• 3G / 4G Wireless Systems, Smart−Phones and Webtablets
NCP6361
VBATT
Battery or
System
Supply
Bypass
FB
Enable
BPEN
Bypass Control
Bypass
VCON
AGND
FSEL
EN
Vout Control
Thermal
Protection
Enabling
DCDC
1.0A
3.43/6.00 MHz
PVIN
10uF
SW
0.47uH
PGND
V_OUT
4.7uF
Figure 1. NCP6361 Block Diagram
© Semiconductor Components Industries, LLC, 2014
1
April, 2014 − Rev. 5
Publication Order Number:
NCP6361/D