3-Pin Synchronous Step-Up DC/DC Converter
Features
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Schottky Diode Embedded, Saving Cost
and Space
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Low Start-up Voltage (0.9V)
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High Efficiency up to 88%
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Low Quiescent Current
n
Low Ripple and Noise
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Available Output Voltage: 2.0V,2.7V,2.8V,
3.0V, 3.3V,3.8V and 5.0V
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Space Saving Packages: SOT-89, SOT-23
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Pb-Free Package
PAM2400
General Description
The PAM2400 is a high efficiency step-up DC/DC
converter, delivering a fixed output voltage of
2.0V, 2.7V, 2.8V, 3.0V, 3.3V, 3.8V or 5.0V. The
device starts up with an input voltage as low as
0.9V at 1mA load. The Pulse Frequency
Modulation (PFM) scheme provides optimized
performance for applications with light load and
low input voltages.
The PAM2400 employs a built-in synchronous
rectifier, instead of requiring an external Schottky
diode, so that to improve system efficiency and
save system cost and PCB area.
The internal PFM control circuit operates at
constant switching frequency of 100KHz. Only
three external components are required. The
space saving SOT-89 and SOT-23 packages make
t h e PA M 2 4 0 0 i d e a l f o r s p a c e c o n s c i o u s
applications.
Applications
n
n
n
n
n
n
Pagers
Cameras
Wireless Microphones
Pocket Organizers
Battery Backup Suppliers
Portable Instruments
Typical Application
V
IN
L1
100 μ H
V
O
Block Diagram
SW
PAM2400
VOUT
VOUT
1M
SW
-
GND
+
C
IN
22 μ F
+
+
C
O
47 μ F
1.25V REF
Enable
GND
OSC 100KHz
Power Analog Microelectronics
,
Inc
www.poweranalog.com
12/2007 Rev 1.0
1
3-Pin Synchronous Step-Up DC/DC Converter
Pin Configuration & Marking Information
SOT89-3
V: Voltage Code
X: Internal Code
Y: Year
W: Week
PAM2400
P2400V
XXXYW
1
2
SOT23-3
3
3
CC: Product Code of PAM2400
V: Voltage Code
Y: Year
W: Week
CCVYW
1
Pin Number
1
2
3
2
Name
GND
VOUT
SW
Ground
Output
Switch Pin
Function
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
.
Supply Voltage............................................ 6.0V
SW pin Voltage.............................................
6.0V
SW pin Switch Current..................................0.4A
Operating Temperature Range.........-40
°
C to 85
°
C
Storage Temperature Range...........-65
°
C to 150
°
C
Lead Temperature (Soldering 5 Sec.)...........300
°
C
Thermal Information
Parameter
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient)
Internal Power Dissipation
Symbol
θ
JC
θ
JA
P
D
Package
SOT89-3
SOT-23
SOT89-3
SOT-23
SOT89-3
SOT-23
Maximum
45
130
160
250
550
400
Unit
°C/W
°C/W
mW
Power Analog Microelectronics
,
Inc
www.poweranalog.com
12/2007 Rev 1.0
2
3-Pin Synchronous Step-Up DC/DC Converter
Electrical Characteristic
C
IN
=22 μ F,C
O
=47 μ F,T
A
=25°C, unless otherwise noted.
Parameter
Output Voltage Accuracy
Input Voltage
Start-Up Voltage
Hold-on Voltage
Supply Current
(Vo pin)
V
IN
V
STA RT
V
HOLD
I
DD1
I
DD2
I
O
=1mA
I
O
=0mA,V
IN
=2V to 0V
V
O
=V
O
X 1.05
V
O
=V
O
X 0.95
Vo=2.0V
Vo=2.7V
No-Load Input Current
I
IN
I
O
=0mA，
V
IN
=1.5V
Vo=2.8V
Vo=3.0V
Vo=3.3V
Vo=3.8V
Vo=5.0V
SW Leakage Current
SW Switch-On Resistance
Oscillator Duty Cycle
Oscillator Frequency
Efficiency (Note 2)
R
ON
DC
f
OS C
η
V
SW
=5V,V
IN
=V
O
+0.5V
Isw=50mA
V
IN
=V
O
* 90%
Current Limit Appears
PAM2400
Symbol
Test Conditions
V
IN
=1.5V, I
O
=1mA
MIN
-3
TYP
MAX
+3
5.5
UNIX
%
V
V
V
μA
μA
0.9
0.4
8.5
33
19
23
25
26
29
34
45
1.0
0.6
12
μA
1.0
1.0
70
70
80
100
85
90
130
μA
Ω
%
kHz
%
Peak value
Note 1: V
O
means the nominal output voltage
Note 2: Refer to “Efficiency vs Output Current” curve
Power Analog Microelectronics
,
Inc
www.poweranalog.com
12/2007 Rev 1.0
3
3-Pin Synchronous Step-Up DC/DC Converter
Typical Performance Characteristics
C
IN
=22 μ F,C
O
=47 μ F,T
A
=25°C, unless otherwise noted.
Vo=2.0V
1.Output voltage vs Output current
4. Output Voltage vs Temperature
PAM2400
2.4
2.2
2.1
Output voltage(V)
Output voltage(V)
Vin=0.9V
Vin=1.2V
Vin=1.5V
2.06
2.02
1.98
1.94
1.9
2
1.8
1.6
1.4
0
30
60
90
120
150
Output current(mA)
0
30
60
90
120
150
Temperature(℃)
90
80
70
2.Efficiency vs Output Current
14
12
10
5. I
DD1
vs Temperature
Efficiency(%)
IDD1(uA)
Vin=0.9V
Vin=1.2V
Vin=1.5V
60
50
40
30
20
10
0
0
20
40
60
80
100
120
Output current(mA)
8
6
4
2
0
0
30
60
90
120
150
Temperature(℃)
1.2
1
3.Start up Voltage and Hold on voltage vs
Output Current
Input voltage(V)
0.8
0.6
0.4
0.2
0
0
5
10
15
Output current(mA)
20
25
Start up
Hold on
Power Analog Microelectronics
,
Inc
www.poweranalog.com
12/2007 Rev 1.0
4
3-Pin Synchronous Step-Up DC/DC Converter
Typical Performance Characteristics
(continued)
C
IN
=22 μ F,C
O
=47 μ F,T
A
=25°C, unless otherwise noted.
Vo=2.7V
3
2.5
PAM2400
1.Output voltage vs Output current
2.8
4. Output Voltage vs Temperature
Output voltage(V)
2
Output voltage(V)
2.76
2.72
2.68
2.64
2.6
1.5
1
Vin=0.9V
Vin=1.2V
Vin=1.5V
0.5
0
0
30
60
Output current(mA)
90
120
0
30
60
90
120
150
Temperature(℃)
90%
80%
70%
2.Efficiency vs Output Current
16
14
12
5. I
DD1
vs Temperature
IDD1(uA)
Vin=0.9V
Vin=1.2V
Vin=1.5V
Efficiency
60%
50%
40%
30%
20%
10%
0%
0
20
40
60
80
100
120
Output current(mA)
10
8
6
4
2
0
0
30
60
90
120
150
Temperature(℃)
1.2
1
0.8
3.Start up Voltage and Hold on voltage vs
Output Current
Vin(V)
0.6
0.4
0.2
0
0
5
10
15
Output current(mA)
20
25
Start up
Hold on
Power Analog Microelectronics
,
Inc
www.poweranalog.com
12/2007 Rev 1.0
5
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