|
|
PDF AAT3176 Data sheet ( Hoja de datos )
| Número de pieza | AAT3176 | |
| Descripción | 500mA LED Flash Driver IC | |
| Fabricantes | Anadigics | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AAT3176 (archivo pdf) en la parte inferior de esta página. Total 15 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
ChargePumpTM
General Description
The AAT3176 is a high output current, high efficiency, low
noise, low profile charge pump converter IC, ideal for
multi-function LED photo-flash applications where solu-
tion cost, size, and efficiency are critical. The charge
pump is capable of delivering up to 500mA of output cur-
rent and can be easily programmed in 16 steps with a
single GPIO output through AnalogicTech's S2Cwire™
(Simple Serial Control) interface. This allows smooth
transitions and flexible adjustment of brightness in flash
or other lighting modes. Operating at a fast 1MHz switch-
ing frequency, the dual-mode (1x/2x) operation of the
internal charge pump offers excellent power efficiency for
both flash and movie modes and combined with a low
external parts count (one 1μF flying capacitors and small
bypass capacitors at VIN and OUT), the AAT3176 is ide-
ally suited for small, battery-powered applications.
The maximum current for both Flash and Movie mode is
set by two independent external resistors. The MODE pin
is adopted to select the LED current between Movie
(Torch) and Flash mode.
The AAT3176 has a thermal management system to pro-
tect the device in the event of short-circuit, open-circuit,
and over-temperature condition. Built-in soft-start cir-
cuitry prevents excessive in-rush current during start-
up. The shutdown feature disconnects the load from VIN
and reduces quiescent current to less than 1.0μA.
The AAT3176 is available in the 2.2 x 2.2mm Pb-free
10-pin TDFN package.
PRODUCT DATASHEET
AAT3176
500mA LED Flash Driver IC
Features
• 2.7V to 5.5V Supply Voltage Range
• Up to 500mA Output Drive Capability at 3.6V VIN
• Flexible Brightness Control
▪ 16 Step Output Current by S2Cwire
• Separate External Resistors to Set Maximum Flash and
Movie-Mode Current
• Dual Mode 1x/2x Charge Pump
• < 1.0μA in Shutdown
• Small Application Circuit
• Automatic Soft-Start Limits Inrush Current
• Open- and Short-Circuit Protection
• Thermal Shutdown Protection
• -40 to +85°C Temperature Range
• 10-pin TDFN2.2x2.2 Package
Applications
• Digital Still Cameras (DSC)
• LED Photo Flash/Torch
• Mobile Handsets
• PDAs and Notebook PCs
Typical Application
C1
1µF
2.7V to 5.5V
Movie
C1+
VIN
C1-
VOUT
CIN
4.7µF
AAT3176
EN
Flash
EN/SET
MODE
GND
FL
RSETF
RSETM
COUT
2.2µF
Flash
LED
RM RF
3176.2009.04.1.0
www.analogictech.com
1
1 page  
www.DataSheet4U.com
ChargePumpTM
Typical Characteristics
Quiescent Current vs. Input Voltage
(VF = 3.6V; RSET = 105kΩ)
5.0
-40°C
4.5 25°C
4.0 85°C
3.5 0°C
3.0
2.5
2.0
1.5
1.0
0.5
0.0
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
100%
90%
80%
70%
Efficiency vs. Input Voltage
(RSET = 105kΩ; IF = 100mA)
VF = 2.7V
VF = 3.0V
VF = 3.3V
VF = 3.6V
60%
50%
40%
30%
2.7
3.1
3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
100%
90%
80%
70%
60%
50%
40%
30%
2.7
Efficiency vs. Input Voltage
(RSETF = 35.7kΩ; IF = 300mA)
VF = 2.7V
VF = 3.0V
VF = 3.3V
VF = 3.6V
3.1 3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
PRODUCT DATASHEET
AAT3176
500mA LED Flash Driver IC
Shutdown Current vs. Input Voltage
(VF = 3.6V; EN = 0V)
1
0.9 -40°C
0°C
0.8 25°C
0.7 85°C
0.6
0.5
0.4
0.3
0.2
0.1
0
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
100%
90%
80%
70%
60%
50%
40%
30%
2.7
Efficiency vs. Input Voltage
(RSETF = 52.3kΩ; IF = 200mA)
VF = 2.7V
VF = 3.0V
VF = 3.3V
VF = 3.6V
3.1 3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
100%
90%
80%
70%
60%
50%
40%
30%
2.7
Efficiency vs. Input Voltage
(RSETF = 21kΩ; IF = 500mA)
VF = 2.7V
VF = 3.0V
VF = 3.3V
VF = 3.6V
3.1 3.5 3.9 4.3 4.7 5.1 5.5
Input Voltage (V)
3176.2009.04.1.0
www.analogictech.com
5
5 Page 
www.DataSheet4U.com
ChargePumpTM
Application Information
Flash and Movie Mode
LED Current Setting
The AAT3176 has two independent LED current setting
pins for LED current in flash and movie mode: RSETF and
RSETM. The MODE pin is designed to select which current
set flows through the LED. When MODE is high, the cur-
rent set by RSETF is the maximum LED current; when
MODE is low, the maximum current is set by RSETM. The
calculation method of the LED current set resistor value
RSET is the same for either mode and can be calculated
using the following formula:
1.22
RSETF = RSETM = ILED · 8652
Table 2 shows some examples of 1% standard metal film
resistor values for different maximum LED currents
(DATA = 1) in movie and flash mode.
RSETM
(kΩ)
210.0
174.0
150.0
130.0
118.0
105.0
Maximum LED
Current (mA)
50
60
70
80
90
100
RSETF
(kΩ)
105.0
69.8
52.3
42.2
35.7
30.1
26.1
23.7
21.0
Maximum LED
Current (mA)
100
150
200
250
300
350
400
450
500
Table 2: Maximum LED Current
RSETM and RSETF Example.
LED current can be set to levels lower than maximum via
S2C DATA transferred through the EN/SET pin, corre-
sponding to percentage of the maximum setting value.
In movie mode, continuous high level of EN/SET lights
the LED light continuously at the programmed current.
In flash mode, EN/SET high level duration controls flash
time; the maximum flash time is 1 second for 500mA
LED current limited by the thermal characteristics of the
package. Figure 2 shows the operating waveform of the
AAT3176 driving an LED for 500ms flash time in flash
mode with 500mA LED current at 3.6V VIN (2x mode).
PRODUCT DATASHEET
AAT3176
500mA LED Flash Driver IC
VIN
(5V/div)
IIN
(1A/div)
VF
(2V/div)
ILED
(1A/div)
VC1
(5V/div)
VRSETF
(2V/div)
Time (100ms/div)
Figure 2: AAT3176 Operating Waveform
at 500mA LED Current with
500ms Flash Time (RSETF = 21kΩ).
Thermal Considerations
The AAT3176 is designed to deliver continuous LED cur-
rent in movie mode. The limiting characteristic for max-
imum safe operating output LED current is package
power dissipation. In order to obtain high operating cur-
rents, careful device layout and circuit operating condi-
tions must be taken into account. The following discus-
sions assume that the AAT3176 is mounted on a printed
circuit board utilizing the minimum recommended foot-
print as stated in the “Printed Circuit Board Layout
Recommendations” section of this datasheet.
At any given ambient temperature (TA), the maximum
package power dissipation can be determined by the fol-
lowing equation:
PD(MAX) =
(TJ(MAX) - TA)
θJA
The AAT3176 is available in the TDFN2.2x2.2-10 pack-
age, which has 71.4°C/W of thermal resistance (θJA).
With 125°C TJ(MAX), its PD(MAX) is 1.4W. The maximum
power dissipation occurs when the mode transfers from
1x to 2x. If the die temperature rises above the thermal
limit of 140°C, the internal thermal protection circuit
activates to shut down the charge pump and recovers
when the die temperature drops below 125°C.
To avoid entering thermal protection in flash mode at the
500mA high flash LED current setting, the flash time
should not exceed 1 second at 25°C ambient tempera-
ture. Longer flash time causes the junction temperature
to increase quickly, causing thermal shut down. The LED
current recovers automatically when the junction tem-
perature decreases.
3176.2009.04.1.0
www.analogictech.com
11
11 Page | ||
| Páginas | Total 15 Páginas | |
| PDF Descargar | [ Datasheet AAT3176.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AAT3170 | High Current LED Flash Driver Charge Pump IC |  ANALOGICTECH |
| AAT3171 | High Efficiency Charge Pump |  AAT |
| AAT3172 | High Current LED Flash Driver Charge Pump IC | ANALOGICTECH |
| AAT3174 | High Current LED Flash Driver Charge Pump IC | ANALOGICTECH |
| 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 |