|
|
PDF PT4107 Data sheet ( Hoja de datos )
| Número de pieza | PT4107 | |
| Descripción | Universal High Brightness LED Driver | |
| Fabricantes | Powtech | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de PT4107 (archivo pdf) en la parte inferior de esta página. Total 10 Páginas | ||
|
No Preview Available !
PT4107
Universal High Brightness LED Driver
with Improved Current Regulation and EMI Performance
GENERAL DESCRIPTION
The PT4107 is a high voltage buck control IC for
constant LED current regulation. It allows efficient
operation of High Brightness (HB) LEDs from voltage
sources ranging from 18VDC up to 450VDC or
110VAC/220VAC. The PT4107 controls an external
MOSFET at fixed switching frequency from 25 kHZ to
200 kHZ. The frequency can be programmed using an
external resistor. A proprietary peak current control
method keeps constant average LED currents for wide
input and output ranges. The output current can be
programmed from a few milliamps up to more than 1A.
The output current on one LED string also can be
programmed to any value between zero and its
maximum value by applying an external control voltage
at the linear dimming control input of the PT4107.
Moreover, PT4107 provides a low-frequency PWM
dimming input that can accept an external control
signal with duty ratio of 0-100% and a frequency of up
to a few kilohertz.
Frequency jittering is used to reduce the EMI.
ORDERING INFORMATION
FEATURES
z Proprietary constant-current control.
z Wide input range from 18V to 450V or
110VAC/220VAC
z Applications from a few mA to more than 1A
Output
z up to hundreds of LEDs
z PWM Low-Frequency Dimming via Enable pin
z Linear Dimming via LD pin
z Frequency jittering for better EMI performance
z Programmable Over temp Protection (OTP)
APPLICATION
z AC/DC LED Driver applications
z RGB Backlighting LED Driver
z Signal and Decorative LED lighting
TEMPERATURE
PACKAGE
RANGE
ORDERING PART
NUMBER
SOP-8
-40℃ to 85℃
PT4107ESOH
Note:
xxxxxX
Assembly Factory Code
Lot Number
TRANSPORT
MEDIA
Tape and Reel
2500 units
MARKING
PT4107
xxxxxX
TYPICAL APPLICATION CIRCUIT
D1
1N4004
1N4004
C1
400V
C2
AC 22µF
R1
47KO
C3
1µF
VIN
LD GATE
PWMD
CS
D2
SBD
L1 LED(s)
2mH
Q1
4N60
1N4004
1N4004
NTC
ROTP GND RI
SW RT1
5K NTC
R2
300KO
R3
0.71
O
China Resources Powtech (Shanghai) Limited
PT4107_DS Rev EN_1.3
WWW.CRPOWTECH.COM
Page 1
1 page  
PT4107
Universal High Brightness LED Driver
with Improved Current Regulation and EMI Performance
OPERATION DESCRIPTION
PT4107 is a high voltage buck controller for LED
driver. The high input voltage from the rectified
110VAC or 220VAC is clamped to about 20V by an
external resistor and an internal Zener. When the
voltage at the VIN pin exceeds the UVLO threshold the
gate drive is enabled. The output current is controlled
by means of limiting peak current in the external power
MOSFET. A current sense resistor is connected in
series with the source terminal of the MOSFET. The
voltage from the sense resistor is applied to the CS pin
of the PT4107. When the voltage at CS pin exceeds a
peak current sense voltage threshold, the gate drive
signal terminates, and the power MOSFET turns off.
The threshold is internally set, or it can be programmed
externally by applying voltage to the LD pin. When soft
start is required, a capacitor can be connected to the LD
pin to allow this voltage to ramp at a desired rate,
therefore, assuring that output current of the LED
ramps gradually.
frequency.
And Ipd is the additional current due to the system
delay. Normally the system delay is about 400 ns.
( )I pd
=
VIN − n × Vled
L
× Td
(2)
The changed peak current is used to compensate the
different inductor ripple current at different application
to make sure the average LED current is constant at a
wide range of input and output voltage.
After the peak current compensation, the LED current
is programming easily when the inductor, operating
frequency, and startup resistor is determined.
I LED
= Vref
Rcs
=
275mV
Rcs
(3)
The application note provides more information how to
choose them.
LED Current Control
The peak current of the LED is programmed by an
external resistor connected to CS pin. And the peak
current is changed adaptively at different input and
output to get the constant average LED current. The
peak current Ip*
Ip* = Vref _ cs + Ipd
Rcs
(1)
= Vref × (1+ 0.8× D) + [(VIN −VDD )/ R1− IDD ] + Ipd
Rcs
K
VIN
Vref
D
K*VIN
R1
R2
D*Vref
R3
A1
Vref_cs
R5
R4
Where Vref = 275mV, D=VOUT/VIN is the duty cycle of
the controller, VIN is the rectified voltage from the AC,
VDD = 20V, R1 is the start up resistor connected between
VIN and VDD, IDD is the operating current dependent on
the operating frequency and the MOSFET
connected to GATE. It increases with operating
frequency and gate capacitance of the MOSFET. It is
about 2mA when 4N60 is used at 100 kHZ operating
Dimming
The PT4107 can drive up to tens of High-Brightness
(HB) LEDs or multiple strings of HB LEDs. The LED
arrays can be configured as a series or series/parallel
connection. The PT4107 regulates constant current that
ensures controlled brightness and spectrum of the LEDs,
and extends their lifetime. The PT4107 features an
enable pin (PWMD) that allows PWM control of
brightness. To keep the user from seeing the LED turn
on and off, the switching speed must be greater than
100 Hz. Above 100 Hz, the human eye averages the on
and off times, seeing only an effective brightness that is
proportional to the LED’s on-time duty cycle. The
dimming frequency of PT4107 is up to 20 kHz.
The PT4107 can also control brightness of LEDs by
programming continuous output current of the LED
driver (so-called linear dimming) when a control
voltage is applied to the LD pin.
Thermal Protection
A thermistor (NTC) connected to ROTP pin can prevent
the LED from overheating. An internal current
IROTP = 24000/ (RI [kΩ]) [μA] is sourcing from the
ROTP pin. The current is about 80μA when RI is equal to
300k Ohm. And the controller will shut down the
system when the voltage of ROTP pin is less than 1V.
When the overheating situation is released, the system
recovers to normal operation.
Frequency shuffling for EMI improvement
The frequency jittering (switching frequency
modulation) is implemented in PT4107. The oscillator
frequency is modulated with a random source so that
the tone energy is spread out. The spread spectrum
China Resources Powtech (Shanghai) Limited
PT4107_DS Rev EN_1.3
WWW.CRPOWTECH.COM
Page 5
5 Page | ||
| Páginas | Total 10 Páginas | |
| PDF Descargar | [ Datasheet PT4107.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 |