|
|
PDF PT4101 Data sheet ( Hoja de datos )
| Número de pieza | PT4101 | |
| Descripción | White LED Step-Up Converter | |
| Fabricantes | Powtech | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de PT4101 (archivo pdf) en la parte inferior de esta página. Total 7 Páginas | ||
|
No Preview Available !
GENERAL DESCRIPTION
The PT4101 is a step-up DC/DC converter designed for
driving up to 5 white LEDs in series from a single cell
Lithium Ion battery with constant current. Because it
directly regulates output current, the PT4101 is ideal for
driving light emitting diodes (LEDs) whose light
intensity is proportional to the current passing through
them, not the voltage across their terminals. A single
external resistor sets LED current between 2mA and
20mA, which can then be easily adjusted using either a
DC voltage or a pulse width modulated (PWM) signal
up to 100KHz. Its low 104mV feedback voltage
reduces power loss and improves efficiency. The OV
pin monitors the output voltage and turns off the
converter if an over-voltage condition is present due to
an open circuit condition. The PT4101 is available in
SOT23-6 packages.
PT4101
White LED Step-Up Converter
FEATURES
z Drives Up to 5 Series White LEDs from 3V
z Up to 87% Efficiency
z 1.25MHz Fixed Switching Frequency
z Low 104mV Feedback Voltage
z Open Load Shutdown
z PWM Dimming
z SOT23-6 Packages
APPLICATIONS
z Cell Phones
z Handheld Computers and PDAs
z Digital Cameras
z Small LCD Displays
ORDERING INFORMATION
PACKAGE
TEMPERATURE
RANGE
ORDERING PART
NUMBER
SOT23-6
-40 oC to 85 oC
PT4101B23F
TRANSPORT
MEDIA
Tape and Reel
3000 units
MARKING
4101
TYPICAL APPLICATIONS
Figure 1. Li-Ion Driver for Four White LEDs
0.89
Vin=3.6V
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.80
2mA
5mA
10mA
Iout (mA)
2*LED
3*LED
4*LED
5*LED
15mA
20mA
Figure 2. Efficiency vs Number of LEDs
China Resources Powtech (Shanghai) Limited
PT4101_DS Rev EN_2.2
WWW.CRPOWTECH.COM
Page 1
1 page  
PT4101
White LED Step-Up Converter
APPLICATION INFORMATION
z Inductor Selections
For most of the applications of the PT4101, it is recommended to use an inductor of 22uH. Although small size is
one of the major factors in selecting an inductor, the smaller and thinner inductors give higher core losses at
1.25MHz and DRC, resulting in lower efficiencies. The following tab le provides a list of recommended inductors:
PART
NUMBER
LQH3C220
CDRH3D16-220
LB2012B220M
LEM2520-220
EJPC220KF
DCR
（Ω）
0.71
0.53
1.7
5.5
4.0
CURRENT RATING
（mA）
250
350
75
125
160
MANUFACTURER
MURATA
SUMIDA
TAIYO YUDEN
TAIYO YUDEN
PANASONIC
z Capacitor Selection
The small size of ceramic capacitors makes them ideal for PT4101 applications. X5R and X7R types are
recommended because they retain their capacitance over wider voltage and temperature ranges than other types such
as Y5V or Z5U. A 1μF input capacitor and a 0.22 μF output capacitor are sufficient for most PT4101 applications.
z Diodes Selection
Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for PT4101
applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode, while the
diode capacitance (CT or CD) represents the switching losses. For diode selection, both forward voltage drop and
diode capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward
voltage drop and larger diode capacitance, which can cause significant switching losses at the 1.25MHz switching
frequency of the PT4101. A Schottky diode rated at 100mA to 200mA is sufficient for most PT4101 applications.
Some recommended Schottky diodes are listed in the following table:
PART NUMBER
CMDSH-3
CMDSH2-3
BAT54
FORWARD
CURRENT
（mA）
100
200
200
VOLTAGE
DROP
（V）
0.58@100mA
0.49@200mA
0.53@100mA
DIODE
CAPACITANCE
（pF）
7.0@10V
15@10v
10@25v
MANUFACTURER
Central
Central
Zetex
z LED Current Control
The LED current is controlled by the feedback resistor.
The feedback reference is 104mV. The LED current is
104mV/Rfb. In order to have accurate LED current,
precision resistors are preferred (1% is recommended).
The formula and table for RFB selection are shown
below
RFB = 104mV/ILED
ILED（mA）
5
10
15
20
RFB Value（Ω）
20.8
10.4
6.93
5.1
China Resources Powtech (Shanghai) Limited
PT4101_DS Rev EN_2.2
WWW.CRPOWTECH.COM
Page 5
5 Page | ||
| Páginas | Total 7 Páginas | |
| PDF Descargar | [ Datasheet PT4101.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| PT4101 | 15 Watt 48V Isolated DC-DC Converter (Rev. A) |  Texas Instruments |
| PT4101 | White LED Step-Up Converter | Powtech |
| PT4101B23F | White LED Step-Up Converter | Powtech |
| PT4102 | 15 Watt 48V Isolated DC-DC Converter (Rev. A) | Texas Instruments |
| 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 |