|
|
PDF LSP5502 Data sheet ( Hoja de datos )
| Número de pieza | LSP5502 | |
| Descripción | 2A Synchronous Step Down DC/DC Converter | |
| Fabricantes | Lite-On | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LSP5502 (archivo pdf) en la parte inferior de esta página. Total 11 Páginas | ||
|
No Preview Available !
LSP5502
2A Synchronous Step Down DC/DC Converter
FEATURES
2A Output Current
Wide 4.5V to 27V Operating Input Range
Integrated 120mΩ Power MOSFET Switches
Output Adjustable from 0.925V to 24V
Up to 96% Efficiency
Programmable Soft-Start
Stable with Low ESR Ceramic Output Capacitors
Fixed 400KHz Frequency
Cycle-by-Cycle Over Current Protection
Input Under Voltage Lockout
8-Pin SOP Package
GENERAL DESCRIPTION
The LSP5502 is a monolithic synchronous buck
regulator. The device integrates 120mΩ MOSFETS
that provide 2A continuous load current over a wide
operating input voltage of 4.5V to 27V. Current mode
control provides fast transient response and
cycle-by-cycle current limit.
An adjustable soft-start prevents inrush current at turn
on. In shutdown mode, the supply current drops
below 1µA.
This device, available in an 8-pin SOP package,
provides a very compact system solution with minimal
reliance on external components.
TYPICAL APPLICATION
Distributed Power Systems
Networking Systems
FPGA, DSP, ASIC Power Supplies
Green Electronics/ Appliances
Notebook Computers
PIN ASSIGNMENT
SOP-8L
(TOP View)
BS 1
8 SS
IN 2
7 EN
SW 3
6 COMP
GND 4
5 FB
PIN DESCRIPTION
Name
BS
No.
1
IN
SW
GND
FB
2
3
4
5
COMP
6
EN 7
SS 8
Description
Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver.
Connect a 0.01uF capacitor between BS and SW.
Input Supply. Bypass this pin to G with a low ESR capacitor. See Input Capacitor
in the Application Information section.
Switch Output. Connect this pin to the switching end of the inductor.
Ground.
Feedback Input. The voltage at this pin is regulated to 0.925V. Connect to the
resistor divider between output and ground to set output voltage.
Compensation Pin. See Stability Compensation in the Application Information
section.
Enable Input. When higher than 2.5V, this pin turns the IC on. When lower than
1.3V, this pin turns the IC off. Output voltage is discharged when the IC is off. This
pin should not be left open.
Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from
SS to GND to set the soft-start period. A 0.1µF capacitor sets the soft-start period
to 15ms. To disable the soft-start feature, leave SS unconnected.
1/11 Rev. 1.7
www.liteon-semi.com
Free Datasheet http://www.nDatasheet.com
1 page  
LSP5502
2A Synchronous Step Down DC/DC Converter
The input capacitor needs to be carefully selected to maintain sufficiently low ripple at the supply input of the
converter. A low ESR capacitor is highly recommended. Since large current flows in and out of this capacitor during
switching, its ESR also affects efficiency.
The input capacitance needs to be higher than 10µF. The best choice is the ceramic type; however, low ESR
tantalum or electrolytic types may also be used provided that the RMS ripple current rating is higher than 50% of the
output current. The input capacitor should be placed close to the IN and G pins of the IC, with the shortest traces
possible. In the case of tantalum or electrolytic types, they can be further away if a small parallel 0.1µF ceramic
capacitor is placed right next to the IC.
Output Capacitor
The output capacitor also needs to have low ESR to keep low output voltage ripple. The output ripple voltage is:
VRIPPLE = IOUTMAX K RIPPLE RESR
+
8
•
VIN
f SW 2 LCOUT
(3)
where IOUTMAX is the maximum output current, KRIPPLE is the ripple factor, RESR is the ESR of the output capacitor, fSW
is the switching frequency, L is the inductor value, and COUT is the output capacitance. In the case of ceramic output
capacitors, RESR is very small and does not contribute to the ripple. Therefore, a lower capacitance value can be
used for ceramic capacitors. In the case of tantalum or electrolytic capacitors, the ripple is dominated by RESR
multiplied by the ripple current. In that case, the output capacitor is chosen to have sufficiently low ESR.
For ceramic output capacitors, typically choose a capacitance of about 22µF. For tantalum or electrolytic capacitors,
choose a capacitor with less than 50mΩ ESR.
Optional Schottky Diode
During the transition between high-side switch and low-side switch, the body diode of the low side power MOSFET
conducts the inductor current. The forward voltage of this body diode is high. An optional Schottky diode may be
paralleled between the SW pin and GND pin to improve overall efficiency. Table 2 lists example Schottky diodes and
their Manufacturers.
Table 2-Diode Selection Guide
Part Number Voltage/Current Rating
Vendor
B130
30V,1A
Lite-on Semiconductor Corp.
MBRS130
30V,1A
International Rectifier
VIN = 12V
R4
100k
C1
22 uF /16 V
C2
0.1uF
1
2 IN
BS 3
SW
LSP 5502
7 EN
FB 5
SS GND COMP
8
C3
0.1uF
46
C4
2.2nF
C5
R3 47pF
6.8k
C6
10nF
L1
VOUT = 5V/2A
15uH/2A
R1
44.2k
C7
R2
10k
D1
B130/SK13
22µF/10V
CERAMIC
x2
(Option)
5/11
www.liteon-semi.com
Rev. 1.7
Free Datasheet http://www.nDatasheet.com
5 Page 
LSP5502
2A Synchronous Step Down DC/DC Converter
PACKAGE INFORMATION
Symbol
A
A1
A2
B
C
D
E
e
H
L
θ
Dimensions In Millimeters
Min.
Nom.
Max.
1.35 1.6 1.75
0.1 0.25
1.25
1.45
1.55
0.31
0.41
0.51
0.1 0.2 0.25
4.8 4.9
5
3.8 3.9
4
1.27 BSC
5.7 6 6.3
0.4
0.71
1.27
0ο 8ο
Dimensions In Inches
Min.
Nom.
Max.
0.053
0.004
0.063
0.069
0.01
0.049
0.012
0.057
0.016
0.061
0.02
0.0039
0.008
0.01
0.192
0.196
0.2
0.148
0.154
0.16
0.050 BSC
0.224
0.236
0.248
0.015
0ο
0.028
0.05
8ο
11/11
www.liteon-semi.com
Rev. 1.7
Free Datasheet http://www.nDatasheet.com
11 Page | ||
| Páginas | Total 11 Páginas | |
| PDF Descargar | [ Datasheet LSP5502.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LSP5502 | 2A Synchronous Step Down DC/DC Converter | Lite-On |
| LSP5503 | 3A Synchronous Step Down DC/DC Converter |  Liteon Semiconductor |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |