PAM2421,PAM2422,PAM2423
3A,4.5A,5.5A PWM Step-Up DC/DC Converter
Features
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Greater than 90% Efficiency
Adjustable Output Voltage Up to 24V
Internal 24V Power MOSFET
Peak Current 3A,4.5A,5.5A
520kHz Frequency
Built-in Over-Voltage Protection (OVP)
Open Protection
Programmable Soft-Start Function
Thermal Shutdowns
Under-Voltage-Lockout
Over-Current Protection
SOP-8(EP) Package
General Description
The PAM242x devices are high-performance,fixed
frequency, current-mode PWM step-up DC/DC
converter that incorporate internal power
MOSFETs. The PAM242x includes an integrated
power MOSFET that supports peak currents of up
to 3A/4.5A/5.5A.
The PAM2 42x utilizes simple ex ternal loop
compensation allowing optimization between
component size, cost, and AC performance across
a wide range of applications. Additional functions
include an externally programmable soft-start
function for easy inrush current control, internal
over-voltage pr otection (OVP) ,c ycle-by- cyc le
current limit protection, under voltage lock-out and
thermal shutdown.
The PAM242x is available in the small SOP-8(EP)
package.
Applications
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TFT LCD Monitors
Battery-Powered Equipment
Set-Top Boxes
DSL and Cable Modems and Routers
Typical Application
SS34
VOUT
12V/800mA
SW
SS
PAM242x
EN
COMP
R3
51k
C7
2.2nF
AGND
C6
47pF
FB
R2
10k
C8
10nF
R1
85k
C4
10uF
C5
470uF
L1
VIN
3.6V~5.5V
C1
470μF
C2
10μF
PGND
6.8
μ
H
VIN
C3
1μF
Power Analog Microelectronics
,
Inc
www.poweranalog.com
02/2012 Rev1.1
1
PAM2421,PAM2422,PAM2423
3A,4.5A,5.5A PWM Step-Up DC/DC Converter
Block Diagram
Pin Configuration & Marking Information
Top View
SOP-8(EP)
PGND
1
VIN
2
EN
3
COMP
4
8
7
6
5
SW
SS
FB
AGND
PCN: Product Code of PAM242x
XXX: Internal Code
V:
Voltage Code
Y:
Year
W: Week
Power Analog Microelectronics
,
Inc
www.poweranalog.com
02/2012 Rev1.1
2
PAM2421,PAM2422,PAM2423
3A,4.5A,5.5A PWM Step-Up DC/DC Converter
Pin Descriptions
Pin Number
1
2
3
4
5
6
Name
PGND
IN
EN
COMP
AGND
FB
Function
Power Ground
Supply Input.
Enable Control. Connect to a logic high level to enable the IC. Connect to a logic low level
to disable the IC. When unused, connect EN pin to IN (do not leave pin floating).
Error Amplifier Compensation Node.
Analog Ground
Feedback Input. Connect this pin a res istor divider from the output to set the output
voltage. FB is regulated to 1.262V.
Sof t Start Control Input. Connect a capacitor from this pin to Ground to set soft-start
7
SS
timing duration. SS is discharged to ground in shutdown. SS may be left unconnected if
soft start is not desired.
8
SW
E xposed
PAD
Switch Output. Connec t this pin to the inductor and the schottky diode. To minimize E MI,
minimize the PCB trace path between this pin and the input bypass capac itor.
Connected to gound
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
.
SW to Ground...................................
–0.3V to 28V
VIN, EN, FB, SS, COMP to Ground........................
......................................................
–0.3V to 6.5V
Continuous SW Current..............Internally Limited
Operating Temperature Range.............................
...................................................
–40
to 150
C
C
Storage Temperature Range
.........
–55
to 150
C
C
Lead Temperature (Soldering, 10 sec)
..........
300
C
Recommended Operating Conditions
Junction Temperature...................
-
40
℃
to 125
℃
Ambient Temperature .....................
-
40
℃
to 85
℃
Thermal Information
Parameter
Thermal Resistance
(Junction to Case)
Thermal Resistance
(Junction to Ambient)
Package
SOP-8(EP )
SOP-8(EP )
Symbol
θ
JC
θ
JA
Maximum
75
℃/W
180
Unit
Power Analog Microelectronics
,
Inc
www.poweranalog.com
02/2012 Rev1.1
3
PAM2421,PAM2422,PAM2423
3A,4.5A,5.5A PWM Step-Up DC/DC Converter
Electrical Characteristic
At T
A
=25
,V
IN
=V
EN
=5V,,unless otherwise specified.
C
PARAMETER
Input Voltage
Under Voltage Lockout
Thres hold
Under Voltage Lockout
Hysteresis
Quiescent Supply Current
Supply Current in S hutdown
Switching Frequency
Maximum Dut y Cyc le
FB Feedback Voltage
FB Input Current
FB Volt age Line Regulation
Switch Current Limit
VFB from 2.7V to 5.5V
PAM2421
PAM2422
PAM2423
PAM2421
Switch On Res istance
Switch Leak age Current
Soft Start Pin Bias Current
Logic High Threshold
Logic Low Threshold
EN Pull Down Resistor
Thermal Shutdown
Temperature
Thermal Shutdown
Hysteresis
PAM2422
PAM2423
VSW = 10V, EN = Ground
VSS = 1.2V
EN Pin
EN Pin
2
1.4
0.4
1
160
40
VIN=3.2V
Duty Cycle = 70%
3
4.5
5.5
130
100
70
15
4.5
7
uA
uA
V
V
MΩ
℃
℃
mΩ
A
VIN Rising
CONDITIONS
MIN
2.7
2.5
200
VFB = 1.4V,
Not Switching
VFB = 1.0V,
Switc hing
EN = Ground
85
1.237
1.262
0
0.05
1.287
80
0.15
0.25
3
0.1
520
0.35
5
1
TYP
MAX
5.5
UNIT
V
V
mV
mA
uA
kHz
%
V
nA
%/V
Power Analog Microelectronics
,
Inc
www.poweranalog.com
02/2012 Rev1.1
4
PAM2421,PAM2422,PAM2423
3A,4.5A,5.5A PWM Step-Up DC/DC Converter
Typical Operating Characteristics
At T
A
=25
,V
IN
=V
EN
=5V,V
FREQ
=0V,unless otherwise specified.
C
Efficiency vs Output Current (Vo=12V)
100 %
90 %
80 %
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0%
1
10
100
Lo ad Cu rren t (mA)
10 00
Vin=3.6V
Vin=4.2V
Vin=5V
Efficiency vs Output Current (Vo=15V)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1
10
100
Lo ad Current (m A)
1 000
Vin=3 .6V
Vin=4 .2V
Vin=5 V
Efficiency vs Output Current (Vo=5V)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1
10
100
1000
O ut put Current (mA )
10000
V in=2. 7V
V in=3. 6V
V in=4. 2V
1 00%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Efficiency vs Input Voltage (Vo=5V)
Io=1m A
Io=10 mA
Io=10 0m A
Io=50 0m A
Io=1A
2. 5
3
3 .5
4
4.5
5
Inp ut Vo lt ag e(V )
Efficiency vs Input Voltage (Vo=12V)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
3
3.5
4
4.5
5
5. 5
Inpu t Voltage (V)
1mA
10mA
100mA
500mA
1A
1 00 %
90 %
80 %
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0%
3
Efficiency vs Input Voltage (Vo=15V)
1mA
10mA
100m A
500m A
3 .5
4
4 .5
Inp ut Vo lta ge (V)
5
5 .5
Power Analog Microelectronics
,
Inc
www.poweranalog.com
02/2012 Rev1.1
5
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