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Ultra-Efficient Charge Pumps for Six White/RGB LEDs in 3mm x 3mm Thin QFN

Achieves Industry's Highest Efficiency Using the Industry's First Negative Charge Pump Driving Six White/RGB LEDs Independently

Product Details

Key Features

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 6
# LED Channels 6
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.024
Dimming Ratio (max) 240
Dimming Control I2C Serial
POUT (W) 0.6
ICC (mA) (max) 0.1
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TQFN/16
Budgetary
Price (See Notes)
2.85
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Simplified Block Diagram

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Parameters

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 6
# LED Channels 6
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.024
Dimming Ratio (max) 240
Dimming Control I2C Serial
POUT (W) 0.6
ICC (mA) (max) 0.1
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TQFN/16
Budgetary
Price (See Notes)
2.85

Key Features

  • Six Adaptive Current Regulators
  • Independent Voltage Supply for Each LED
  • Individual LED Brightness Control (MAX8647)
  • 24mA to 0.1mA Dimming Range
    • I²C Interface (MAX8647)
    • Serial-Pulse Dimming Logic (MAX8648)
  • ±2% Accuracy, ±0.4% Matching (typ)
  • Low 70µA Quiescent Current
  • Low 1µA Shutdown Current
  • Inrush Current Limit
  • TA Derating Function Protects LEDs
  • 16-Pin, 3mm x 3mm Thin QFN Package

Applications/Uses

  • Camera Flash or RGB Indicators
  • Cellular Phones and Smartphones
  • PDAs, Digital Cameras, and Camcorders
  • White LED Backlighting, Single or Dual Display
  • Wide-Gamut RGB LED Display Backlighting

Description

The MAX8647/MAX8648 drive up to six white LEDs or two sets of RGB LEDs with regulated constant current for display backlight and fun light applications. By utilizing an inverting charge pump and extremely low-dropout adaptive current regulators, these ICs achieve very high efficiency over the full 1-cell Li+ battery voltage range and even with large LED forward voltage mismatch. The 1MHz fixed-frequency switching allows for tiny external components. The regulation scheme is optimized to ensure low EMI and low input ripple. The MAX8647/MAX8648 include thermal shutdown, open- and short-circuit protection.

The MAX8647 features an I²C serial port, while the MAX8648 features a three-wire serial-pulse logic interface. Both devices support independent on/off and dimming for main and subbacklights. The dimming ranges are pseudo-logarithmic from 24mA to 0.1mA and off in 32 steps. Both devices include a temperature derating function to safely allow bright 24mA full-scale output current setting while automatically reducing current to protect LEDs at high ambient temperatures above +60°C.

The MAX8647/MAX8648 are available in a 16-pin, 3mm x 3mm thin QFN package (0.8mm max height).

Simplified Block Diagram

MAX8647, MAX8648: Typical Operating Circuit MAX8647, MAX8648: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Sampling:
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.