|
|
Número de pieza | AA1700 | |
Descripción | Constant Current White LED driver | |
Fabricantes | Agamem Microelectronic | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de AA1700 (archivo pdf) en la parte inferior de esta página. Total 10 Páginas | ||
No Preview Available ! www.DataSheet4U.com
AA1700Agamem Microelectronics Inc.
PRELIMINARY
Constant Current White LED driver
OVERVIEW
The AA1700 is a high frequency boost DC/DC converter with constant current output that drives white LEDs
or similar. The LED current is set with the external resistor. Soft start circuitry prevents excessive current
drawn from the supply during power on. Any number of LEDs can be connected in series as long as the
summed forward voltages do not lead to exceed the specified operating output voltage range. This IC works
with a wide operating supply range (1.8V to 15V) and low current consumption, is optimal for use in
high-efficiency white LED driver.
FEATURES
• Drives Up to 8 LEDs in Series.
• Second or more string of LEDs can be added.
• Low current consumption: Typically 5.5 mA in operation, 1 µA or less in stand-by.
• PWM mode operation of the boost circuit (frequency range: 10 kHz to 1 MHz).
• Incorporates a soft start circuit and adjustable soft start time.
• Timer latch LED short-circuit protection circuit (SP).
• On/off control function.
• Available in an 8-pin TSSOP or SOP package.
PIN Configuration
(TOP VIEW)
IN 1
SP 2
VCC 3
CTL 4
8 ER
7 CLK
6 GND
5 P0
APPLICATIONS
• LCD Bias Supplies
• White LED Backlighting
• Handheld Devices
• Digital Cameras
• Portable Applications
©Copyright Agamem Microelectronics Inc.
1
www.agamem.com.tw 2007/1/22
1 page www.DataSheet4U.com
AA1700Agamem Microelectronics Inc.
PRELIMINARY
Constant Current White LED driver
(Continued)
Parameter
Symbol
Condition
Output section
Output current
setting section/
Control section
Entire device
Output voltage
Output source
current
Output sink current
Pull down resistance
Pin voltage
Input off condition
Input on condition
Pin current range
Stand-by current
Average supply
current
VOH1
VOH2
VOL1
VOL2
IO+
IO –
RO
VCTL
IOFF
ION
ICTL
ICCS
ICC
RB = 390 Ω , IO = –15 mA
RB = 750 Ω , VCC = 1.8 V
IO = –10 mA
RB = 390 Ω , IO = 15 mA
RB = 750 Ω , VCC = 1.8 V
IO = 10 mA
RB = 390 Ω , VO = 0.9 V
RB = 390 Ω , VO = 0.3 V
—
RB = 390 Ω
—
CTL pin open or VCC
RB = 390 Ω
Value
Unit
Min Typ Max
1.0 1.2 — V
0.8 1.0 — V
— 0.1 0.2 V
— 0.1 0.2 V
— –30 –20 mA
30 60 — mA
20 30 40 kΩ
0.2 0.3 0.4 V
–20 —
0 µA
— — –45 µ A
–1.8 — –0.1 mA
——
1 µA
— 5.5 9.3 mA
HOW TO SET THE TIME CONSTANT FOR SOFT START AND SHORT CIRCUIT DETECTION
1. Soft Start
A soft start function, which gradually increases the width of the output pulses at power on, will be applied if a
capacitor is connected to the SP pin. This can prevent rush currents and overshoot when the power supply is
turned on.
Soft start time can be measured by the following equation. (The time until the output ON duty reaches
approximately 50%)
tS [s] = 0.35 × CPE [uF]
2. Timer Latch Short Circuit Protection
When the load conditions suddenly change due to load effect, the short-circuit protection comparator outputs the
high-level signal (VOM+) and the capacitor CPE connected to the SP terminal starts charging. When the external
capacitor CPE has been charged to approximately 0.8V, the latch circuit is set, the output terminal is fixed to low
level, and the dead-time is set to 100%. However, the latch circuit is not reset unless the power for the latch
circuit is turned off or restarted by the on/off control.
• Short circuit detection time
tPE [s] = 0.8 × CPE [uF]
©Copyright Agamem Microelectronics Inc.
5
www.agamem.com.tw 2007/1/22
5 Page |
Páginas | Total 10 Páginas | |
PDF Descargar | [ Datasheet AA1700.PDF ] |
Número de pieza | Descripción | Fabricantes |
AA1700 | Constant Current White LED driver | Agamem Microelectronic |
AA170EB01 | SXGA Display Module | Mitsubishi |
AA170EC01 | SXGA | Mitsubishi |
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 |