|
|
PDF CAT3637 Data sheet ( Hoja de datos )
| Número de pieza | CAT3637 | |
| Descripción | 6-Channel Programmable High Efficiency Quad-Mode LED Driver | |
| Fabricantes | Catalyst Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de CAT3637 (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
6-Channel Programmable High Efficiency
Quad-Mode™ LED Driver
www.DataSheet4U.com
CAT3637
FEATURES
High efficiency 1.33x charge pump
Quad-Mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives 6 LEDs between 30mA and 0mA each
1-wire EZDimTM interface with 2mA step
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
Tiny 3mm x 3mm, 16-pad TQFN package
APPLICATIONS
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
ORDERING INFORMATION
Part Number
CAT3637HV3-GT2
Quantity
per Reel
2000 (1)
Note:
(1) NiPdAu Plated Finish (RoHS-compliant)
16-lead TQFN 3mm x 3mm Package
Package
Marking
JAAM
DESCRIPTION
The CAT3637 is a high efficiency Quad-Mode fractional
charge pump that can drive up to six LEDs program-
mable by a 1-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 2.5V to 5.5V.
The EN/SET logic input functions as a chip enable and a
digital programming interface for setting the current in the
LED channels. The 1-wire pulse-programming interface
supports 15 linear steps from zero current to 30mA full-
brightness in 2mA steps.
The device is available in a tiny 16-pad TQFN 3 x 3mm
package with a maximum height of 0.8mm.
Catalyst Semiconductor’s Quad-Mode 1.33x, charge pump
switching architecture is patented.
For Ordering Information details, see page 13.
PIN CONFIGURATION
(top view)
16 15 14 13
LED6 1
12 C2-
LED5 2
11 C2+
LED4 3
10 C1-
LED3 4
9 C1+
5678
TYPICAL APPLICATION CIRCUIT
1µF 1µF
VIN
2.5V
to
5.5V
CIN
1µF
1-Wire
Programming
C1-
VIN
C1+ C2- C2+
VOUT
CAT3637
EN/SET
GND
LED1
LED2
LED3
LED4
LED5
LED6
VOUT
COUT
1µF
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5033 Rev. A
1 page  
www.DataCShAeetT4U3.c6om37
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Switching Frequency vs. Temperature
1.2
1.1
1.0 1.5x Mode
0.9
0.8
1.33x, 2x Mode
0.7
0.6
-40 -20 0 20 40 60
TEMPERATURE [°C]
80
Output Resistance vs. Input Voltage
10
VF = 3.3V
8
2x
6 1.33x 1.5x
4
2
1x
0
5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0
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
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-5033 Rev. A
5 Page 
www.DataCShAeetT4U3.c6om37
Unused LED Channels
External Components
For applications with 5 LEDs or less, unused LEDs
can be disabled by connecting the LED pin directly to
VOUT, as shown on Figure 4. If LED pin voltage is
within 1V of VOUT, then the channel is switched off
and a 200μA test current is placed in the channel to
sense when the channel moves below VOUT – 1V.
1µF 1µF
The driver requires two external 1μF ceramic
capacitors 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.
VIN
2.5V
to
5.5V
CIN
1µF
1-Wire
Programming
C1-
VIN
C1+ C2- C2+
VOUT
CAT3637
EN/SET
GND
LED1
LED2
LED3
LED4
LED5
LED6
Figure 5. Five LED Application
Protection Mode
VOUT
COUT
1µF
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.
If an LED is disconnected, the output voltage VOUT
automatically limits at about 5.5V. This is to prevent
the output pin from exceeding its absolute maximum
rating.
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
5.0V may be used with the CAT3637. 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 CAT3637 will
stay in 1x mode for lower supply voltage of 0.2V. This
helps improve the efficiency and extends battery life.
Figure 6. Recommended Layout
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-5033 Rev. A
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet CAT3637.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| CAT3636 | 6-Channel LED Driver | Catalyst Semiconductor |
| CAT3637 | 6-Channel Programmable High Efficiency Quad-Mode LED Driver |  ON Semiconductor |
| CAT3637 | 6-Channel Programmable High Efficiency Quad-Mode LED Driver | Catalyst 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 |