LP8556 6 Channel High-Efficiency/Efficacy LED Backlight Driver | TI.com

LP8556 (ACTIVE) 6 Channel High-Efficiency/Efficacy LED Backlight Driver

 

Description

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.

Features

  • High-efficiency DC/DC boost converter with integrated 0.19-Ω power MOSFET and three switching frequency options: 312 kHz, 625 kHz, and 1250 kHz
  • 2.7-V to 36-V Boost switch input voltage range supports multi-cell Li-Ion batteries
    (2.7-V to 20-V VDD input range)
  • 7-V to 43-V Boost switch output voltage range supports as few as 3 WLEDs in series per channel and as many as 12
  • Configurable channel count (1 to 6)
  • Up to 50 mA per channel
  • PWM and / or I2C brightness control
  • Phase-shift PWM mode reduces audible noise
  • Adaptive dimming for higher LED drive optical efficiency
  • Programmable edge-rate control and spread spectrum scheme minimize switching noise and improve EMI performance
  • LED fault (short and open) detection, UVLO, TSD, OCP, and OVP (up to 6 threshold options)
  • Available in tiny 20-pin, 0.4-mm pitch DSBGA package and 24-pin, 0.5-mm pitch WQFN package

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Parametrics

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Part number Order Channels (#) Vin (Min) (V) Vin (Max) (V) Vout (Min) (V) Vout (Max) (V) Switching frequency (Max) (kHz) Type LED current per channel (mA) LED (#) Topology Shutdown current (Typ) (uA) Peak efficiency (%) LED configuration Function Features Operating temperature range (C) Package Group Package size: mm2:W x L (PKG)
LP8556 Order now 6     2.7     20     7     48     1250     Inductive     50     60     Boost     0.1     95     Parallel       I2C Control     -30 to 85     DSBGA | 20
WQFN | 24    
See datasheet (DSBGA)
24WQFN: 16 mm2: 4 x 4 (WQFN | 24)    
LP8553 Order now 4     2.7     22     10     40     1250     Inductive     50     40     Boost     1     93         PWM Control     -30 to 85     DSBGA | 25     25DSBGA: 8 mm2: 2.8 x 3 (DSBGA | 25)    
LP8555 Order now 12     2.7     20     7     28     1000     Inductive     50     96     Boost     3     93     6 LED channels
Dual
Parallel    
Backlight     Adjustable Switch Frequency
Analog/PWM Mixed Dimming
CABC
Edge Rate Control
I2C Control
Integrated Switch
OVP
PWM Control
Thermal Shutdown    
-40 to 85     DSBGA | 36     See datasheet (DSBGA)    
LP8557 Order now 6     2.7     5.5     7     28     1000     Inductive     25     48     Boost     0.001     93     6 LED channels
Parallel    
  CABC
Edge Rate Control    
-30 to 85     DSBGA | 16     See datasheet (DSBGA)    
TPS61176 Order now 6     2.7     6.5     2.7     38     1000     Inductive     35     60     Boost     2     90     6 LED channels