PAM2319
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Features
n
Supply Voltage:2.7V to 5.5V
n
Output Voltage:
Vo1 ADJ/1000mA
Vo2 ADJ/2000mA
n
Low Quiescent Current:
Channel 1: 40uA; Channel 2: 55uA
n
High Efficiency:
n
Switching Frequency: 3MHz(Channel 1)
2.5MHz(Channel 2)
n
Internal Synchronous Rectifier
n
Soft Start
n
Under-Voltage Lockout
n
Short Circuit Protection
n
Thermal Shutdown
n
Small WDFN3X3-12L Pb-Free/Halogen
Free Package
n
RoHS/REACH Compliant
General Description
The PAM2319 is a dual step-down current-mode,
DC-DC converter. At heavy load, the constant-
f r e q u en c y P W M c o n tr o l p e r f o r m s e x c e l l e nt
stability and transient response. To ensure the
longest battery life in portable applications, the
PA M 2 3 1 9 p r o v i d e s a p o w e r - s a v i n g P u l s e -
Skipping Modulation (PSM) mode to reduce
quiescent current under light load operation.
The PAM2319 supports a range of input voltages
from 2.7V 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 adjustable from 1.0V to 3.3V .
Both channels employ internal power switch and
synchronous rectifier to minimize external part
c o u n t a n d r e a l i z e h i g h e f f i c i e n c y. D u r i n g
shutdown, the input is disconnected from the
output and the shutdown current is less than
0.1
μ
A. Other key features include under-voltage
lockout,soft-start,short circuit protection and
thermal shutdown.
Applications
n
Portable Electronics
n
Personal Information Appliances
n
Wireless and DSL Modems
Typical Application
L1
VIN
2.7 V--5 .5V
C in
1 0 uF
VIN1( 4)
Ci 1
n
1 uF
(6 )SW1
1
1 .0u H
2
Co 1
10u F
R 11
300k
C fw1
10 0 pF
Vo1
1 .8 V/1 00 0 m A
0
0
EN 1(9 )
(7 )FB 1
0
R 12
150k
PAM23 19
VIN2 (2 )
C i n2
1uF
L2
0
2
( 12) SW2
1
1 .0 uH
Vo 2
Co 2
10 uF
R 21
150k
C fw2
10 0 pF
1 .2 V/2 00 0 m A
0
EN 2 (1 0)
(1 )FB2
0
R 22
150k
(5 )PGN D1
(8)AGND 1
(3)AGND 2
(1 1)P GN D2
0
0
0
0
0
Figure 1. Adjustable Voltage Regulator
Power Analog Microelectronics
,
Inc
www.poweranalog.com
1
12/2011 Rev1.1
PAM2319
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Block Diagram
3MHz
/2.5MHz
OSC
SLOPE
COMP
+
IAMP
VIN
-
OSC
MAIN
SWITCH
(
PCH
)
FREQ
SHIFT
S Q
-
EA
+
FBx
COMP
SWITCHING
LOGIC
AND
RS LATCH
BLANKING
CIRCUIT
R Q
ANTI
-
SHOOT
-
THRU
SWx
EN
0
.
6VREF
+
IRCMP
SYNCHRONOUS
RECTIFIER
(
NCH
)
-
GND
Note: 1. This block diagram above just shows one channel.
Power Analog Microelectronics
,
Inc
www.poweranalog.com
2
12/2011 Rev1.1
PAM2319
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Pin Configuration and Marking Information
TOP VIEW
WDFN-12L 3x3
FB2
1
2
3
4
5
6
GND
12
11
SW2
VIN2
VIN1
PGND1
SW1
10 E N2
9
8
7
FB
1
EN 1
BN: Product Code of PAM2319
v
1
: Output Voltage 1
v
2
: Output Voltage 2
(refer to “
Ordering
Information”
)
X: Internal Code
Y: Year
W: Week
(Exposed Pad)
Pin Description
QFN3x3
1
2
3
4
5
6
7
8
9
10
11
12
Name
FB2
VIN2
AGND2
VIN1
PGND1
SW1
FB1
AGND1
EN1
EN2
PGND2
SW2
Exposed
PAD
Input voltage pin of
channel 2
.
Signal ground of
channel 2
for small signal components.
Input voltage pin of
channel 1
.
Main power ground pin of
channel 1
Channel 1
switching pin. The drains of the internal main and s ynchronous power
Function
Channel 2
feedback pin internally set to 0.6V.
MOSFET.
Channel 1
feedback pin internally set to 0.6V.
Signal ground of
channel 1
for small signal components.
Enable control input. Pull logic high to enable Vo1. Pull logic low to disable.
Enable control input. Pull logic high to enable Vo2. Pull logic low to disable.
Main power ground pin of
channel 2
Channel 2
switching pin. The drains of the internal main and s ynchronous power
MOSFET.
Connect to GND
Power Analog Microelectronics
,
Inc
www.poweranalog.com
3
12/2011 Rev1.1
PAM2319
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Absolute Maximum Ratings
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
.
Input Voltage...................................-0.3V to 6.5V
E N1, FB1, SW1, EN2, FB 2 and SW2 Pin Voltage....
-0.3V to (V
IN
+0.3V)
Maximum Junction Temperature..................150°
C
Storage Temperature Range...........-65° to 150°
C
C
Soldering Temperature.....................260° 10sec
C,
Recommended Operating Conditions
Supply Voltage..................................2.7V to 5.5V
Ambient Temperature Range............-40 ° to 85 °
C
C
Junction Temperature Range..........-40° to 125 °
C
C
Thermal Information
Parameter
Thermal Resistanc e (Junction to ambient)
Thermal Resistance (Junction to case)
Symbol
θ
JA
θ
JC
Package
WDFN 3x3-12L
WDFN 3x3-12L
Maximum
60
8.5
Unit
°
C/W
°
C/W
Power Analog Microelectronics
,
Inc
www.poweranalog.com
4
12/2011 Rev1.1
PAM2319
Dual High-Efficiency PWM Step-Down DC-DC Coverter
Electrical Characteristic
T
A
=25 C, V
IN
=3.3V, V
O
=1.8V, C
IN
=10µF, C
O
=10µF, L=1.0µH, unless otherwise noted.
Channel 1
PARAMETER
Input Voltage Range
UVLO Threshold
Regulated Feedback Voltage
Reference Voltage Line Regulation
Regulated Output Voltage Acc uracy
Peak Inductor Current
Output Voltage Line Regulation
Output Voltage Load Regulation
Quiescent Current
Shutdown Current
Oscillator Frequenc y
Drain-Sourc e On-State Resistance
SW Leakage Current
Efficiency
PSM Threshold
EN Threshold High
EN Threshold Low
EN Leak age Current
Soft-start
Over Temperature Protection
OTP
Hys teresis
SYMBOL
V
IN
V
IN
Rising
V
UVLO
V
FB
ΔV
F B
V
O
I
PK
LNR
LDR
I
Q
I
SD
f
OSC
R
DS(O N)
I
LSW
η
I
TH
V
EH
V
EL
I
EN
T
ON
OTP
OTH
From EN1 to Output
±
0.01
2
150
30
Output1, Io=500mA,VIN=3.3V
Vin=3.3V
1.5
0.3
I
O
= 100mA
V
O
=90%
V
IN
= 2.7V to 5V, I
O
=10mA
I
O
=1mA to 1000mA
No load
V
EN
= 0V
V
O
= 100%
V
FB
= 0V or V
O
= 0V
P MOSFET
N MOSFET
-2
40
0.1
3
1
0.35
0.35
±
0.01
84
100
0.45
0.45
1
-3
1.5
0.2
0.5
2
80
1
Hysteresis
V
IN
Falling
1.8
0.588
0.6
0.3
+3
0.612
Test Conditions
MIN
2.7
2.4
240
TYP
MAX
5.5
2.5
UNITS
V
V
mV
V
V
% /V
%
A
% /V
%
µA
µA
MHz
MHz
Ω
Ω
µA
%
mA
V
V
µA
mS
°
C
°
C
O
Power Analog Microelectronics
,
Inc
www.poweranalog.com
5
12/2011 Rev1.1
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