|
|
PDF RT8561A Data sheet ( Hoja de datos )
| Número de pieza | RT8561A | |
| Descripción | High Voltage 8-CH LED Driver | |
| Fabricantes | Richtek | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de RT8561A (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
®
RT8561A
High Voltage 8-CH LED Driver
General Description
The RT8561Ais a 40V 8-CH LEDdriver capable of delivering
30mA to each channel with 10 LEDs (3.6V per diode),
total of 80 LEDs with one driver. The RT8561A is a current
mode boost converter operated at 1MHz, wide VIN range
covers from 6V to 24V and the on-chip current switch is
rated at 2.5A.
The PWM output voltage loop regulates the LED pins to
0.6V with an auto-adjustment circuit allowing voltage
mismatches between LED strings. The RT8561A automati-
cally detects and disconnects any unconnected and/or
broken strings during operation from PWM loop to prevent
VOUT from over voltage.
The 1.5% 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 the RT8561A. Analog dimming is linearly
controlled by an external voltage. With an on-chip output
clamping amplifier and a 300kΩ 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 ACTL pin with a PWM
signal.
Other protecting features include programmable output
over voltage protection, LED current limit, PWM switch
current limit and thermal shutdown.
The RT8561A is packaged with a tiny footprint package of
WQFN-24L 4x4 packages.
Ordering Information
RT8561A
Package Type
QW : WQFN-24L 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.
Features
z High Voltage : VIN up to 24V, VOUT up to 40V, Driving
up to 80 x 3.6V LEDs (10 each channel)
z Channel Current Programmable 10mA to 30mA and
Matched to 1.5%
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 Shutdown
z Providing High Accuracy Digital Dimming by PWM
at ACTL Pin
z VIN Under Voltage Lockout
z Over Temperature Protection
z Current Limiting Protection
z Small 24-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
Pin Configurations
(TOP VIEW)
24 23 22 21 20 19
LED1 1
18 VCC
LED2 2
17 CREG
LED3 3
LED4 4
GND
16 LED8
15 LED7
LED5 5
OVP 6
14 LED6
25 13 EN
7 8 9 10 11 12
WQFN-24L 4x4
Marking Information
CZ= : Product Code
CZ=YM
DNN
YMDNN : Date Code
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
DS8561A-02 April 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1
1 page  
RT8561A
Functional Pin Description
Pin No.
1, 2, 3, 4, 5
6
Pin Name
LED1, LED2,
LED3, LED4,
LED5
OVP
Pin Function
Channel 1 to Channel 5 LED current sink. Leave the pin unconnected if not
used.
Over Voltage Protection. PWM boost converter turns off when VOVP goes
higher than 1.2V.
7 VC
PWM boost converter loop compensation node.
8 NC
No Internal Connection.
9 SS
Soft Start Pin, a capacitor of at least 10nF is required for soft start.
10
RISET
A resistor or a current from DAC on this pin programs the full LED current.
11
12
13
14, 15, 16
17
18
19, 20
21, 22, 23, 24,
25 (Exposed Pad)
ACTL
DCTL
EN
LED6, LED7,
LED8
CREG
VCC
SW
GND
Analog/Digital dimming control. When using analog dimming,
ILED
(mA) =
20 x 4.75
RISET (kΩ)
for VACTL
≥ 1.2V.
By adding a 0.1μF filtering capacitor on the ACTL pin, the PWM dimming
signal on the DCTL pin will be averaged out and converted into analog
dimming signal on the ACTL pin.
Chip enable pin, when pulled low, chip is in shutdown mode.
Channel 6 to Channel 8 LED current sink. Leave the pin unconnected if not
used.
1μF capacitor should be placed on this pin to stabilize the 5V output of the
internal regulator. This regulator is for chip internal use only.
Power supply of the chip. For good bypass, a low ESR capacitor is required.
PWM boost converter switch node.
Ground pin of the chip. The exposed pad must be soldered to a large PCB
and connected to GND for maximum power dissipation.
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
DS8561A-02 April 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
5
5 Page 
R1 = 3.3MΩ,
R2 = 100kΩ
VIN
(10V/Div)
VOUT
(20V/Div)
OVP
SW
(20V/Div)
VIN = 12V, All LED Pin Open
Time (2.5ms/Div)
RT8561A
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
DS8561A-02 April 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
11
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet RT8561A.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| RT8561A | High Voltage 8-CH LED Driver | Richtek |
| RT8561D | High Voltage 8-CH 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 |