LP5520TL/NOPB National Semiconductor, LP5520TL/NOPB Datasheet - Page 8

• Manufacturer Part Number: LP5520TL/NOPB
• Description: IC LED DRIVER RGB 25-USMD
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: RGB LED Driverr

Specifications of LP5520TL/NOPB

• Constant Current: Yes
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 3
• Internal Driver: Yes
• Type - Primary: Backlight, Light Management Unit (LMU)
• Type - Secondary: RGB, White LED
• Frequency: 1.22kHz, 19.52kHz
• Voltage - Supply: 2.9 V ~ 5.5 V
• Voltage - Output: 5 V ~ 20 V
• Mounting Type: Surface Mount
• Package / Case: 25-MicroSMD
• Operating Temperature: -30°C ~ 85°C
• Current - Output / Channel: 60mA
• Internal Switch(s): Yes
• Efficiency: 87%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LP5520TLTR

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START-UP SEQUENCE
RESET:
STANDBY:
STARTUP:
BOOST STARTUP: Soft start for boost output is generated in the BOOST STARTUP mode. The boost output is raised in PWM
NORMAL:
In the RESET mode all the internal registers are reset to the default values and the chip goes to STANDBY
mode after reset. <NSTBY> control bit is low after reset by default. Reset is entered always if NRST input is
low or internal Power On Reset is active. Power On Reset (POR) will activate during the chip startup or when
the supply voltage VDD falls below 1.5V. Once VDD rises above 1.5V, POR will inactivate and the chip will
continue to the STANDBY mode.
The STANDBY mode is entered if the register bit <NSTBY> is LOW. This is the low power consumption
mode, when all circuit functions are disabled. Registers can be written in this mode and the control bits are
effective immediately after power up.
When <NSTBY> bit is written high or there is a rising edge in the BRC input, the INTERNAL STARTUP
SEQUENCE powers up all the needed internal blocks (Vref, Bias, Oscillator etc..). To ensure the correct
initialization, a 10 ms delay is generated by the internal state-machine after the trim EEPROM values are
read. If the chip temperature rises too high, the Thermal Shutdown (TSD) disables the chip operation and
STARTUP mode is entered until no thermal shutdown event is present.
mode during the 20 ms delay generated by the state-machine. All LED outputs are off during the 20 ms delay
to ensure smooth startup. The Boost startup is entered from Internal Startup Sequence if <EN_BOOST> is
HIGH or from Normal mode when <EN_BOOST> is written HIGH.
During NORMAL mode the user controls the chip using the Control Registers or the BRC input in stand-alone
mode. The registers can be written in any sequence and any number of bits can be altered in a register in
one write.
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