Features: · Up to 1A total drive current
·Flash timeout protection
· Independent Torch/Flash/Shutdown modes
· LED disconnect in shutdown
· Programmable soft-start limits inrush current
· Over-voltage protection
· Wide voltage range 2.7 to 5.5V
· 1.25MHz constant switching frequency
· Small, low profile package, non-pullback LLP14 (4mm x 4mm)Application· White LED Camera Flash
· White LED Torch (Flashlight)
· DSC (Digital Still Camera) Flash
· Cellular Camera Phone Flash
· PDA Camera Flash
·Camcorder Torch (Flashlight) lampSpecifications
| Regulated LEDs |
1 |
| Total LED Current |
1000 mA |
| Boost Type |
Inductive |
| Switching Frequency |
1250 kHz |
| Efficiency (peak) |
93 % |
| Input Min Voltage |
2.7 Volt |
| Input Max Voltage |
5.5 Volt |
| LED Configuration |
Series |
| Current Matching |
Perfect |
| OutputMax Voltage |
20 Volt |
| Supply Current |
1.47 mA |
| Switching Type |
PWM |
| Special Features |
Up to 4 LEDs, Flash LED driver, timeout protection, active low enable |
| PWM BrightCtrl |
Yes |
| Analog-V BrightCtrl |
No |
| Ambient Light Compensation |
No |
| RGB-LED |
No |
| Temperature Min |
-40 deg C |
| Temperature Max |
85 deg C |
| RegType |
WhiteLED Driver |
| PowerWise |
Yes |
| View Using Catalog |
VIN pin: Voltage to GND ....................7.5V
SW pin: Voltage to GND....................21V
FB pin: Voltage to GND...................... 7V
VC pin: Voltage to GND ............... 1.26V ± 0.3V
SD,T/F pins: Voltage to GND ................ 7.5V
FET-T, FET-F: Voltage to GND.................. 6V
Continuous Power Dissipation (Note 3) ..Internally Limited
Junction Temperature (TJ-MAX ).............. 150°C
Storage Temperature Range .......... -65°C to +150
Maximum Lead Temperature
(Soldering) ........................ (Note 4)
ESD Rating..........................(Note 5)
Human Body Model ......................2.0kVDescriptionThe LM3551 and LM3552 are fixed frequency, current mode step-up DC/DC converters with two integrated NFETs that can be used for precision LED brightness control. The devices are capable of driving loads up to 1A from a single-cell Li-Ion battery.
The LM3551 and LM3552 can drive one or more high current flash LEDs either in a high power Flash mode or a lower power Torch mode using the TORCH/FLASH pin. A programmable Timeout function on the FTO pin forces the internal NFETs to turn off after a certain user defined time. An external SD pin (LM3551) or EN pin (LM3552) is available to put the device into low power shutdown mode. During shutdown, the feedback resistors and the load are disconnected from the input to avoid leakage current paths to ground.
User programmable soft-start circuitry has been integrated to eliminate large inrush currents at start-up. Over-voltage protection circuitry and a 1.25MHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings.
The LM3551 and LM3552 are available in a low profile 14 pin LLP package.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM3551SD |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
| LM3551SDX |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.For more information on Reliability Metrics, please click here.
More Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1495: Application Note 1495 LM3552 White LED Flash Driver Evaluation Board |
626 Kbytes |
27-Sep-06 |
Download |
AN-1495 (Chinese): Application Note 1495 LM3552 White LED Flash Driver Evaluation Board
|
208 Kbytes |
|
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
| AN-1780: Application Note 1780 LM3553 1.2A Dual Flash LED Driver System with I2C Compatible Interface |
1427 Kbytes |
12-Mar-08 |
Download |
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
The LM3551 and LM3552 are fixed frequency, current mode step-up DC/DC converters with two integrated NFETs that can be used for precision LED brightness control. The devices are capable of driving loads up to 1A from a single-cell Li-Ion battery.
The LM3551 and LM3552 can drive one or more high current flash LEDs either in a high power Flash mode or a lower
power Torch mode using the TORCH/FLASH pin. A programmable Timeout function on the FTO pin forces the internal NFETs to turn off after a certain user defined time. Anexternal SD pin (LM3551) or EN pin (LM3552) is available to put the device into low power shutdown mode. During shutdown, the feedback resistors and the load are disconnected from the input to avoid leakage current paths to ground. User programmable soft-start circuitry has been integrated
to eliminate large inrush currents at start-up. Over-voltage protection circuitry and a 1.25MHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings.
The LM3551 and LM3552 are available in a low profile 14 pin LLP package.
LM3551 Data Sheet
