A Product Line of
Diodes Incorporated
PAM2308
DUAL HIGH-EFFICIENCY PWM STEP-DOWN DC-DC CONVERTER
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 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.
Pin Assignments
Features
•
•
•
•
•
•
•
•
•
•
•
Efficiency up to 96%
Only 40μA (typ per channel) Quiescent Current
Output Current: Up to 1A per Channel
Internal Synchronous Rectifier
1.5MHz Switching Frequency
Soft-Start
Under-Voltage Lockout
Short Circuit Protection
Thermal Shutdown
Small WDFN3x3-10L Packages
Pb-Free Package and RoHS Compliant
Applications
•
•
•
•
•
Cellular Phone
Portable Electronics
Personal Information Appliances
Wireless and DSL Modems
MP3 Players
Typical Applications Circuit
Rx1
⎞
⎛
⎟
Figure 1. Adjustable Voltage Regulator
V
OUTx
=
V
REF
⎜
1
+
Rx2
⎠
⎝
PAM2308
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January 2013
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2308
Typical Applications Circuit
(cont.)
V
OUTx
= 1.2V, 1.5V, 1.8V, 2.5V, 2.8V or 3.3V
Figure 2. Fixed Voltage Regulator
Pin Descriptions
Pin
Name
EN1
FB1
VIN2
GND
LX2
EN2
FB2
VIN1
LX1
Pin
Number
1
2
3
4, 9
5
6
7
8
10
Feedback of Channel 1.
Power Input of Channel 2.
Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power
dissipation.
Pin for Switching of Channel 2.
Chip Enable of Channel 2 (Active High).V
EN2
≤
V
IN2
.
Feedback of Channel 2.
Power Input of Channel 1.
Pin for Switching of Channel 1.
Function
Chip Enable of Channel 1(Active High). V
EN1
≤
V
IN1
.
PAM2308
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© Diodes Incorporated
A Product Line of
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PAM2308
Functional Block Diagram
Absolute Maximum Ratings
(@T
A
= +25°C, unless otherwise specified.)
These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may
affect device reliability. All voltages are with respect to ground.
Parameter
Input Voltage
EN1, FB1, LX1, EN2, FB2 AND LX2 Pin Voltage
Maximum Junction Temperature
Storage Temperature Range
Soldering Temperature
Rating
-0.3 to +6.5
-0.3 to (V
IN
+0.3)
150
-65 to +150
260, 10sec
Unit
V
V
°C
°C
°C
Recommended Operating Conditions
(@T
A
= +25°C, unless otherwise specified.)
Parameter
Supply Voltage
Ambient Temperature Range
Junction Temperature Range
Rating
2.5 to 5.5
-40 to +85
-40 to +125
Unit
V
°C
Thermal Information
Parameter
Thermal Resistance (Junction to Ambient)
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Case)
Symbol
θ
JA
θ
JC
P
D
Package
W-DFN3x3-10
W-DFN3x3-10
W-DFN3x3-10
Max
60
8.5
1.66
Unit
°C/W
W
PAM2308
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PAM2308
Electrical Characteristics
(@T
A
= +25°C, V
IN
= 3.6V, V
O
= 1.8V, C
IN
= 10µF, C
O
= 10µF, L = 2.2µH, unless otherwise specified.)
Parameter
Input Voltage Range
Regulated Feedback Voltage
Reference Voltage Line Regulation
Regulated Output Voltage Accuracy
Peak Inductor Current
Output Voltage Line Regulation
Output Voltage Load Regulation
Quiescent Current (per channel)
Shutdown Current (per channel)
Oscillator Frequency
Drain-Source On-State Resisitance
SW Leakage Current
High Efficiency
EN Threshold High
EN Threshold Low
EN Leakage Current
Over Temperature Protection
OTP Hysteresis
Symbol
V
IN
V
FB
ΔV
FB
V
O
I
PK
LNR
LDR
I
Q
I
SD
fosc
R
DS(ON)
I
LSW
η
V
EH
V
EL
I
EN
OTP
OTH
±0.01
150
30
1.5
0.3
I
O
= 100mA
V
IN
= 3V, V
FB
= 0.5V or V
O
= 90%
V
IN
= 2.5V TO 5V, I
O
= 10mA
I
O
= 1mA to 1A
No load
V
EN
= 0V
V
O
= 100%
V
FB
= 0V or V
O
= 0V
I
DS
= 100mA
P MOSFET
N MOSFET
1.2
-3
1.5
0.2
0.5
40
0.1
1.5
500
0.3
0.35
±0.01
96
0.45
0.5
1
0.5
1.5
70
1
1.8
Test Conditions
Min
2.5
0.588
0.6
0.3
+3
Typ
Max
5.5
0.612
Units
V
V
%/V
%
A
%/V
%
µA
µA
MHz
kHz
Ω
Ω
µA
%
V
V
µA
°C
°C
PAM2308
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© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2308
Typical Performance Characteristics
(@T
A
= +25°C, C
IN
= 10µF, C
O
= 10µF, L = 4.7µH, unless otherwise specified.)
PAM2308
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