|
|
PDF CAT3647 Data sheet ( Hoja de datos )
| Número de pieza | CAT3647 | |
| Descripción | 3-Channel Ultra High Efficiency Quad-Mode LED Driver | |
| Fabricantes | Catalyst Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de CAT3647 (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
CAT3647
3-Channel Ultra High Efficiency Quad-Mode™
LED Driver with 32 Dimming Levels
FEATURES
High efficiency 1.33x charge pump
Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives up to 3 LEDs at 30mA each
1-wire EZDim™ 32 linear steps
Power efficiency up to 92%
Low noise input ripple in all modes
“Zero” current shutdown mode
Soft start and current limiting
Short circuit protection
Thermal shutdown protection
RoHS-compliant 16-pad TQFN package
APPLICATION
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
ORDERING INFORMATION
Part Number
CAT3647HV3-GT2
Package
TQFN-16
3mm x 3mm(1)
Notes:
(1) NiPdAu Plated Finish (RoHS-compliant)
(2) Quantity per reel is 2000
Marking
JAAP
PIN CONFIGURATION
(Top View)
DESCRIPTION
The CAT3647 is a high efficiency quad-mode
fractional charge pump that can drive up to three
LEDs programmable by a one wire digital interface.
The inclusion of a 1.33x fractional charge pump mode
increases device efficiency by up to 10% over
traditional 1.5x charge pumps with no added external
capacitors.
Low noise input ripple is achieved by operating at a
constant switching frequency which allows the use of
small external ceramic capacitors. The multi-fractional
charge pump supports a wide range of input voltages
from 2.4V to 5.5V.
The EN/DIM logic input functions as a chip enable and
a digital dimming interface for setting the current in all
the LED channels. The 1-wire pulse-dimming interface
supports 32 linear steps from full-scale down to zero
current.
The device is available in the tiny 16-pad TQFN 3mm
x 3mm package with a max height of 0.8mm.
Catalyst Semiconductor’s Quad-Mode™ 1.33x,
charge pump switching architecture is patented.
TYPICAL APPLICATION CIRCUIT
1µF 1µF
16 15 14 13
LED2 1
12 C2-
LED3 2
11 C2+
NC 3
10 C1-
RSET 4
9 C1+
5678
VIN
2.4V
to
5.5V
CIN
1µF
1-Wire
EZDimTM
Programming
3.74kΩ
C1+
VIN
C1- C2+
C2-
VOUT
CAT3647
EN/DIM
RSET
GND
LED1
LED2
LED3
VOUT
COUT
1µF
20mA
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5030 Rev. A
1 page  
www.DataCShAeetT4U3.c6om47
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 60mA (3 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Switching Frequency vs. Temperature
1.3
Output Resistance vs. Input Voltage
12
1.2
1.5x Mode
1.1
10 2x
8
1.0
0.9 1.33x, 2x Mode
0.8
6
1.5x
4
2
1x
1.33x
0.7
-40
0 40 80
TEMPERATURE [°C]
120
0
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE [V]
Power Up in 1x Mode
Power Up in 1.33x Mode
Power Up in 1.5x Mode
Power Up in 2x Mode
© 2007 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-5030 PD1
5 Page 
Unused LED Channels
For applications not requiring all the channels, it is
recommended the unused LED pins be tied directly to
VOUT (see Figure 4).
1µF 1µF
VIN
CIN
1µF
ENABLE
DIMMING
RSET
C1+
VIN
C1- C2+
C2-
VOUT
CAT3647
EN/DIM
RSET
GND
LED1
LED2
LED3
COUT
1µF
Figure 4. Application with 2 LEDs
Protection Mode
If an LED is disconnected, the driver senses that and
automatically ignores that channel. When all LEDs are
disconnected, the driver goes to 1x mode where the
output is equal to the input voltage.
As soon as the output exceeds about 6V, the driver
resets itself and re-evaluates the mode.
If the die temperature exceeds +150°C, the driver will
enter a thermal protection shutdown mode. When the
device temperature drops by about 20°C, the device
will resume normal operation.
LED Selection
LEDs with forward voltages (VF) ranging from 1.3V to
4.3V may be used. Selecting LEDs with lower VF is
recommended in order to improve the efficiency by
keeping the driver in 1x mode longer as the battery
voltage decreases.
For example, if a white LED with a VF of 3.3V is
selected over one with VF of 3.5V, the driver will stay
in 1x mode for lower supply voltage of 0.2V. This
helps improve the efficiency and extends battery life.
www.DataCShAeetT4U3.c6om47
External Components
The driver requires four external 1μF ceramic capaci–
tors for decoupling input, output, and for the charge
pump. Both capacitors type X5R and X7R are
recommended for the LED driver application. In all
charge pump modes, the input current ripple is kept
very low by design and an input bypass capacitor of
1μF is sufficient.
In 1x mode, the device operates in linear mode and
does not introduce switching noise back onto the
supply.
Recommended Layout
In charge pump mode, the driver switches internally at
a high frequency. It is recommended to minimize trace
length to all four capacitors. A ground plane should
cover the area under the driver IC as well as the
bypass capacitors. Short connection to ground on
capacitors CIN and COUT can be implemented with the
use of multiple via. A copper area matching the TQFN
exposed pad (TAB) must be connected to the ground
plane underneath. The use of multiple via improves
the package heat dissipation.
Figure 5. TQFN-16 Recommended Layout
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-5030 Rev. A
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet CAT3647.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| CAT3643 | 3-Channel Ultra High Efficiency Quad-Mode TM LED Driver | Catalyst Semiconductor |
| CAT3643 | 3-Channel Ultra High Efficiency LED Driver |  ON Semiconductor |
| CAT3644 | 4-Channel Ultra High Efficiency Quad-Mode TM LED Driver | Catalyst Semiconductor |
| CAT3644 | 4-Channel Ultra High Efficiency LED Driver | ON 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 |