Preliminary
Datasheet
LP3205
1.5MHZ,800mA,High Efficiency Synchronous
PWM Step-Down DC/DC Convert
General Description
The LP3205 is a constant frequency, current mode,
PWM step-down converter. The device integrates a
main switch and a synchronous rectifier for high
efficiency. The 2.5V to 5.5V input voltage range makes
the LP3205 is ideally suited for portable electronic
devices that are powered from 1-cell Li-ion battery or
from other power sources within the range such as
cellular phones, PDAs and handy-terminals. Internal
synchronous rectifier with low RDS(ON) dramatically
reduces conduction loss at PWM mode. The internal
synchronous
switch
increases
efficiency
while
eliminate the need for an external Schottky diode.The
switching ripple is easily smoothed-out by small
package filtering elements due to a fixed operation
frequency of 1.5MHz. This along with small SOT-23-5
package provide small PCB area application. Other
features include soft start, lower internal reference
voltage with 2% accuracy, over temperature protection,
and over current protection。
◆ High Efficiency: 93%
◆ 1.5MHz Fixed-Frequency PWM Operation
◆ Adjustable Output From 0.6V to VIN
◆ 1.2V, 1.5V, 1.8V, 2.5V, 3.0Vand 3.3V Fixed
◆ 800mA Output Current, 1.1A Peak Current
◆ No Schottky Diode Required
◆ 95% Duty Cycle Low Dropout Operation
◆ Available in SOT23-5/TSOT23-5 Package
◆ Short Circuit and Thermal Protection
◆ Low than 1µA Shutdown Current
Features
Applications
Portable Media Players
Cellular and Smart mobile phone
PDA
DSC
Wireless Card
Pin Configurations
Ordering Information
LP3205 -
□ □ □ □
□
F: Pb-Free
Package Type
B5: SOT23-5
J5: SOT23-5
Output Voltage Type
A: Adjustable type
12: 1.2V
15: 1.5V
18: 1.8V
25: 2.5V
33: 3.3V
LP3205 – Ver. 1.0 Datasheet
Feb.-2007
Page 1 of 10
Marking Information
Please see website.
Preliminary
Functional Pin Description
Pin Number
1
2
3
4
5
Pin Name
VIN
GND
EN
FB/Vout
LX
Datasheet
LP3205
Pin Function
Power Input
Ground.
Chip Enable(Active High).
Feedback Input Pin,Reference voltage is 0.6 V
Pin For Switching
Function Block Diagram
Absolute Maximum Ratings
■
■
■
■
■
■
■
■
■
■
Input Supply Voltage
EN,VFB Voltage
P-Channel Switch Source Current(DC)
N-Channel Switch Current(DC)
Peak SW Sink and Source Current
Operation Temperature Range
Junction Temperature
Storage Temperture
Lead Temp(Soldering,10sec)
ESD Rating(HBM)
-0.3V to 6.5V
-0.3V to V
in
1100mA
1100mA
1.4A
0℃ to 85℃
125℃
-65℃
to 150℃
260℃
2KV
LP3205 – Ver. 1.0 Datasheet
Feb.-2007
Page 3 of 10
Preliminary
Electrical Characteristics
Datasheet
LP3205
(VIN = 3.6V, VOUT = 2.5V, VREF = 0.6V, L = 4.7µH, CIN= 4.7µF, COUT= 10µF, TA= 25°C, IMAX = 800mA
unless otherwise specified)
Parameter
Input Voltage Range
Operating Supply Current
Standby Mode Supply
Current
Shutdown Current
Reference Voltage
Adjustable Output Range
Symbol
VIN
I
OUT
=0mA,V
FB
=0.5V or V
OUT
=90%
I
OUT
=0mA,V
FB
=0.62V or V
OUT
=103%
I
SHDN
VREF
VOUT
ΔVOUT
ΔVOUT
Output
Voltage
Accuracy
Fixed
ΔVOUT
ΔVOUT
ΔVOUT
ΔVOUT
ΔVOUT
VFB =
VIN
IOUT =
200mA
IOUT =
200mA
VIN =2.2
to 5.5V
VIN = 2.2 to 5.5V, VOUT = 1.2V 0A <
IOUT < 800mA
VIN = 2.2 to 5.5V, VOUT = 1.5V 0A <
IOUT < 800mA
VIN = 2.2 to 5.5V, VOUT = 1.8V 0A <
IOUT < 800mA
VIN = 2.8 to 5.5V, VOUT = 2.5V 0A <
IOUT < 800mA
VIN = 3.5 to 5.5V, VOUT = 3.3V 0A <
IOUT < 800mA
VIN = VOUT + 0.2V to 5.5V, VIN
≧
3.5V 0A < IOUT < 800mA
VIN = VOUT + 0.4V to 5.5V, VIN
≧
2.2V 0A < IOUT < 800mA
EN = GND,Vin=4.2V
For adjustable output voltage
0.58
VREF
−3
−3
−3
−3
−3
−3
−3
-30
VIN = 3.6V
VIN = 3.6V
0.4
0.35
Test Conditions
Min
2.5
300
22
0.1
0.6
Typ
Max
5.5
400
35
1
0.62
VIN
−
0.2
+3
+3
+3
+3
+3
+3
+3
30
0.58
V
V
%
%
%
%
%
%
%
nA
Ω
Ω
uA
Units
V
Adjustable
FB Input
Current
PMOSFET
RON
NMOSFET
RON
P-Channel
Current Limit
EN
Threshold
EN Leakage
Current
IFB
PRDS(ON)
NRDS(ON)
IP(LM)
VEN
VENL
0.9
0.4
--
1
1.5
1.5
A
V
uA
2
LP3205 – Ver. 1.0 Datasheet
Feb.-2007
Page 4 of 10
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