PAM2308 Datasheet, PDF (1/15 Pages) Power Analog Micoelectronics – Dual High-Efficiency PWM Step-Down DC-DC Coverter

PAM2308
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Features
n Efficiency up to 96%
n Only 40μA(Typ. per Channel) Quiescent
Current
n Output Current: Up to 1A per Channel
n Internal Synchronous Rectifier
n 1.5MHz Switching Frequency
n Soft Start
n Under-Voltage Lockout
n Short Circuit Protection
n Thermal Shutdown
n Small 10L WDFN 3x3
Packages
n Pb-Free Package and RoHS Compliant
Applications
n Cellular Phone
n Portable Electronics
n Personal Information Appliances
n Wireless and DSL Modems
n MP3 Players
General Description
The PAM2308 is a dual step-down current-mode,
DC-DC converter. At heavy load, the constant-
frequency PWM control performs excellent
stability and transient response. To ensure the
longest battery life in portable applications, the
PAM2308 provides a power-saving Pulse-
Skipping Modulation (PSM) mode to reduce
quiescent current under light load operation.
The PAM2308 supports a range of input voltages
from 2.5V to 5.5V, allowing the use of a single
Li+/Li-polymer cell, multiple Alkaline/NiMH cell,
USB, and other standard power sources. The dual
output voltages are available for 3.3V, 2.8V, 2.5V,
1.8V, 1.5V, 1.2V or adjustable. All versions
employ internal power switch and synchronous
rectifier for to minimize external part count and
realize high efficiency. During shutdown, the input
is disconnected from the output and the shutdown
current is less than 0.1μA. Other key features
include under-voltage lockout to prevent deep
battery discharge.
Typical Application
V_OUT1
C_OUT1
10μF
R12
V_IN2
C_IN2
4.7μF
C _Fw1
100nF
L1
R11
PAM2308
1
EN1
10
LX1
2
FB1
VIN1 ⁸
4
GND
GND ⁹
3
VIN2
5 _LX2
FB2 ⁷
EN2 ⁶
C_IN1
4 .7 μF
V_IN1
R21
R22
C_FW2
100pF
L2
V_OUT2
C_OUT2
10μF
( ) ^VOUTx
=
V_REF
1+
Rx1
Rx2
Figure 1. Adjustable Voltage Regulator
Power Analog Microelectronics,Inc
www.poweranalog.com
1
07/2008 Rev 1.0