|
|
PDF RT8560 Data sheet ( Hoja de datos )
| Número de pieza | RT8560 | |
| Descripción | High Voltage 4 Channel LED Driver | |
| Fabricantes | Richtek | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de RT8560 (archivo pdf) en la parte inferior de esta página. Total 15 Páginas | ||
|
No Preview Available !
RT8560
High Voltage 4 Channel LED Driver
General Description
The RT8560 is a 60V 4-channel LED driver capable of
delivering 30mA to each channel with 15 LEDs (3.6V per
diode) total 60 LEDs with one driver. The RT8560 is a
current mode boost converter opearated at 1MHz switching
frequency, wide VIN range covers from 7V to 40V and the
on-chip current switch is rated at 1.5A.
The PWM output voltage loop selects and regulates the
LED pin with the highest voltage string to 0.9V allowing
voltage mismatches between LED strings. The RT8560
automatically detects and disconnects any unconnected
and/or broken strings during operation from PWM loop to
prevent VOUT from over voltage.
The 3% matched LED currents on all channels are simply
programmed with a resistor or a current sink. Both analog
dimming and digitally controlled PWM dimming are
supported by RT8560. Analog dimming is linearly
controlled by an external voltage. With an on-chip output
clampping amplifier and a 200kΩ resistor, PWM dimming
signal is easily low-pass filtered to an analog dimming
signal with one external capacitor for noise-free PWM
dimming. A very high contrast ratio true digital PWM
dimming can be achieved by driving EN pin to PWM
shutdown the chip or by driving ACTL pin.
Other protecting features include programmable PWM
output over voltage protection, LED curren limit, PWM
switch current limit and thermal shutdown. The RT8560
is packaged with a tiny footprint package of WQFN-20L
4x4 packages.
Pin Configurations
(TOP VIEW)
20 19 18 17 16
GND 1
15 LED4
GND 2
14 VC
GND 3
GND
13 SS
SW 4
21 12 OVP
SW 5
11 EN
6 7 8 9 10
WQFN-20L 4x4
DS8560-01 April 2011
Features
z High Voltage : VIN up to 40V, VOUT up to 60V, Driving
up to 60 x 3.6V LEDs (15 each channel)
z Channel Current Programmabe 4mA to 30mA and
Matched to 3% Accuracy
z Current Mode PWM 1MHz Boost Converter
z Easy Analog and Digital Dimming Control
z Programmable Soft Start
z Automatic Detecting Unconnected and/or Broken
Channel
z Programmable Over Voltage Protection
z Disconnects LED in Digital Dimming : Providing
High Accuracy Digital Dimming by PWM at ACTL
Pin or EN Pin
z VIN Under Voltage Lockout
z Over Temperature Protection
z Current Limiting Protection
z Small 20-Lead WQFN Package
z RoHS Compliant and Halogen Free
Applications
z UMPC and Notebook Computer Backlight
z GPS, Portable DVD Backlight
z Desk Lights and Room Lighting
Ordering Information
RT8560
Package Type
QW : WQFN-20L 4x4 (W-Type)
Note :
Lead Plating System
G : Green (Halogen Free and Pb Free)
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
www.richtek.com
1
1 page  
RT8560
Functional Pin Description
Pin Number
Pin Name
Pin Function
1, 2, 3, 19, 20,
21 (Exposed Pad)
GND
Ground pin of the chip. The exposed pad must be soldered to a large PCB
and connected to GND for maximum power dissipation.
4, 5 SW
PWM boost converter switch node.
Bipolar power switch base current supply. Typical beta of the power NPN
6
VCC2
switch is approximately 70. VCC2 can be connected either to VCC1 or to a
separate lower voltage, as low as 3V, for better system efficiency and/or
heat concern. A good bypass is necessary.
7
VCC1
Power supply of the chip. For good bypass, a low ESR capacitor is required.
8
RISET
A resistor or a current from DAC on this pin programs the full LED current.
9
10
11
12
13
14
18, 17, 16, 15
ACTL
DCTL
EN
OVP
SS
VC
LED1, LED2,
LED3, LED4
Analog/Digital dimming control. When using analog dimming,
IL ED
=
20mA
×
5.36k
RISET
for VACTL ≥ 1.2V.
By adding a 0.1uF filtering capacitor on ACTL pin, the PWM dimming signal
on DCTL pin will be averaged out and converted into analog dimming signal
on ACTL pin.
Chip enable pin, when low chip is in shutdown mode.
Over voltage protection. PWM boost converter turns off when VOVP goes
higher than 2.5V.
Soft start pin, a capacitor of at least 10nF is required for soft start.
PWM boost converter loop compensation node.
Channel 1 to Channel 4 LED current sink. Leave the pin unconnected if not
us ed.
DS8560-01 April 2011
www.richtek.com
5
5 Page 
VIN
(5V/Div)
IOUT
(50mA/Div)
Line Transient Response
VIN = 10.8V to 13.2V, RISET = 4.8kΩ
Time (50ms/Div)
VIN
(5V/Div)
VOUT
(20V/Div)
SW
(20V/Div)
RT8560
OVP
VIN = 12V, All LED Pin Open
Time (2.5ms/Div)
DS8560-01 April 2011
www.richtek.com
11
11 Page | ||
| Páginas | Total 15 Páginas | |
| PDF Descargar | [ Datasheet RT8560.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| RT8560 | High Voltage 4 Channel LED Driver | Richtek |
| RT8561A | High Voltage 8-CH LED Driver | Richtek |
| RT8561D | High Voltage 8-CH LED Driver | Richtek |
| RT8562 | High Voltage 8 Channel LED Driver | Richtek |
| 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 |