The LP8556 device is a white-LED driver featuring an asynchronous boost converter and six
high precision current sinks that can be controlled by a PWM signal or an
I2C master.The boost converter uses adaptive output voltage control for setting the optimal LED
driver voltages as low as 7 V and as high as 43 V. This feature minimizes the power consumption by
adjusting the output voltage to the lowest sufficient level under all conditions. The converter can
operate at three switching frequencies: 312 kHz, 625 kHz, and 1250 kHz, which can be
set with an external resistor or pre-configured via EPROM. Programmable slew rate control and
spread spectrum scheme minimize switching noise and improve EMI performance.LED current sinks can be set with the PWM dimming resolution of up to 15 bits.
Proprietary adaptive dimming mode allows higher system power saving. In addition, phase shifted LED
PWM dimming allows reduced audible noise and smaller boost output capacitors.The LP8556 device has a full set of fault-protection features that ensure robust
operation of the device and external components. The set consists of input undervoltage lockout
(UVLO), thermal shutdown (TSD), overcurrent protection (OCP), up to 6 levels of overvoltage
protection (OVP), LED open and short detection.The LP8556 device operates over the ambient temperature range of –30°C to +85°C. It is
available in space-saving 20-pin DSBGA and 24-pad WQFN packages.
