AME5251A Datasheet, PDF (1/19 Pages) Analog Microelectronics – Dual 1A, 1.5MHz Synchronous Step-Down Converter

AME
AME5251A
n General Description
The AME5251A is a high efficiency monolithic synchro-
nous dual buck regulator using a constant frequency, cur-
rent mode architecture. Capable of delivering 1A output
cur-rent each channel over a wide input voltage range from
2.5V to 5.5V.
Supply current with no load is 400µA and drops to<1µA
in shutdown.The 2.5V to 5.5V input Voltage range makes
the AME5251A ideally suited for single Li-Ion battery-
powered applications. 100% duty cycle provides low drop-
out operation, extending battery life in portable systems.
PWM pulse skipping mode operation provides very low
output ripple voltage for noise sensitive applications. At
very light load, the AME5251A will automatically skip
pulses in pulse skip mode operation to maintain output
regulation.
The internal synchronous switch increases efficiency
and eliminates the need for an external Schottky diode.
Low output voltages are easily supported with the 0.6V
feedback reference voltage. The AME5251A is available
in small DFN-12A packages.
Other features include soft start, lower internal refer-
ence voltage with 2% accuracy, over temperature protec-
tion, and over current protection.
Dual 1A, 1.5MHz Synchronous
Step-Down Converter
n Features
l High Efficiency: Up to 95%
l Shutdown Mode Draws <1µA Supply Current
l 2.5V to 5.5V Input Range
l Adjustable Output From 0.6V to V_IN
l 1A Output Current Per Channel
l Low Dropout Operation: 100% Duty Cycle
l No Schottky Diode Required
l 1.5MHz Constant Frequency PWM Opera
tion
l Small DFN-12A Packages
l Green Products Meet RoHS Standard
n Applications
l Cellular Telephones
l Personal Information Appliances
l Wireless and DSL Modems
l MPS Players
l Portable Instruments
n Typical Application
VIN1
CIN2
R2
C1
VOUT1
COUT2
L2
VOUT2
AME5251A
ON
OFF
IN2
EN2
SW2
NC2
R3
C2
GND
FB2
FB1
GND
R4
NC1
SW1
CIN1
R1
EN1
IN1
ON
VIN1
OFF
L1
COUT1
Rev.A.04
1