Description of the LP8862-Q1
3
Description of the LP8862-Q1
The LP8862-Q1 is an automotive high-efficiency LED driver with integrated boost/SEPIC converter. It has
2 high-precision current sinks that can be controlled by a PWM input signal.
The boost converter has adaptive output voltage control based on the LED current sink headroom
voltages. This feature minimizes the power consumption by adjusting the voltage to lowest sufficient level
in all conditions. Boost controller supports spread spectrum for switching frequency and an external
synchronization with dedicated pin. The high switching frequency allows the LP8862-Q1 to avoid
disturbance for AM radio band.
The LP8862-Q1 can drive an external p-FET to disconnect the input supply from the system in the event
of a fault, reduce inrush current and standby power consumption.
The input voltage range for LP8862-Q1 is from 4.5 V to 40 V to support automotive stop/start and load
dump condition. LP8862-Q1 supports PWM brightness dimming ratio up to 10 000:1 for input PWM
frequency of 200 Hz. The LP8862-Q1 integrates extensive safety and protection features.
3.1
Features
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Two High-Precision Current Sinks
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Current Matching 1% (typical)
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Output Current up to 160 mA/Channel
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Dimming Ratio 10 000:1 at 200 Hz PWM input
•
Integrated Boost/SEPIC for LED String Power
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Output Voltage up to 45 V
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Switching Frequency 300 kHz to 2.2 MHz
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Boost Synchronization Input
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Spread Spectrum
•
Input Voltage Operating Range 4.5 V to 40 V
•
Power-Line FET Control for Inrush Current Protection and Standby Energy Saving
•
Extensive Safety and Fault Tolerance Features
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Fault Output
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Input Voltage OVP, UVLO, and OCP
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Open and Shorted LED Fault Detection
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Thermal Shutdown
•
Minimum Number of External Components
3.2
Applications
•
Automotive Infotainment, Instrument Cluster and Backlighting Systems
5
SNVU478A – July 2015 – Revised October 2015
LP8862-Q1EVM Evaluation Module
Copyright © 2015, Texas Instruments Incorporated