peculiarity
High voltage DC/DC boost converter with four switching frequency options with integrated FET: 156/312/625/1250 kHz
Supports 1X ... 5-fold cell lithium-ion battery
Programmable PWM resolution from 8 bits to 13 bits
I 2C and PWM brightness control
The PWM output frequency and the resistance current pass through the LED
4 LED outputs for LED fault (short/open) detection
Low input voltage, overtemperature, overcurrent detection and shutdown
Minimum number of external components
Micro SMD - 25 package, 2.466 x 2.466 x 0.6 mm
illustrate
The LP8551 is a driver for a white LED integrated boost converter. It has 4 adjustable current sinks that can be controlled via PWM input or a serial interface compatible with my 2C.
Adaptive output voltage control of boost converter LED drive voltage. This feature minimizes power consumption by adjusting the minimum adequate level of the voltage under various conditions.
There is 8-bit LED output current resolution and up to 13-bit PWM resolution for smooth and precise brightness control. A proprietary phase-shifted PWM control LED output is used to reduce peak current in a boost converter, resulting in a smaller boost capacitor. The phase shift plan also eliminates noise.
Internal EEPROM is used to store configuration data. This makes it possible to have a minimal external component count, making this solution very small.
The LP8551 has a safety feature that allows it to detect open or short fault LED outputs. Overcurrent conditions as well as low input voltage and increased monitoring and chip are turned on in case of these events. By reducing the brightness of the backlight when it has reached the set temperature, the thermal derating function prevents the device from overheating.
The LP8551 is a national micro SMD-25 package.
Note: This file is not a complete data sheet. For more details about this product or to order samples, please contact your local national semiconductor sales office or visit //www.national.com/support/dir.html.
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