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480mA White LED 1x/1.5x/2x Charge Pump for Backlighting and Camera Flash

Product Details

Key Features

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 8
# LED Channels 8
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.4
PWM Dimming Freq. (kHz) (max) 5
Dimming Control Analog
PWM
Serial Pulse
POUT (W) 2
ICC (mA) (max) 6
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TQFN/24
Budgetary
Price (See Notes)
3.45
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Simplified Block Diagram

Technical Docs

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Parameters

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 8
# LED Channels 8
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.4
PWM Dimming Freq. (kHz) (max) 5
Dimming Control Analog
PWM
Serial Pulse
POUT (W) 2
ICC (mA) (max) 6
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TQFN/24
Budgetary
Price (See Notes)
3.45

Key Features

  • Powers Up to 8 LEDs
    Up to 30mA/LED Drive for Backlight
    Up to 400mA Total Drive for Flash
  • 85% Average Efficiency (PLED / PBATT) Over Li+ Battery Discharge
  • 0.7% Typical LED Current Matching
  • Adaptive 1x/1.5x/2x Mode Switchover
  • Flexible Brightness Control
  • Single-Wire, Serial Pulse Interface (5% to 100%)
    2-Bit (3 Levels) Logarithmic Logic
  • Low Input Ripple and EMI
  • Low 0.1µA Shutdown Current
  • 2.7V to 5.5V Supply Voltage Range
  • Soft-Start Limits Inrush Current
  • Output Overvoltage Protection
  • Thermal-Shutdown Protection
  • 24-Pin Thin QFN, 4mm x 4mm Package
  • Applications/Uses

    • Camera Phones
    • Cell Phones/Smartphones
    • LCD Backlights
    • LED Camera Flashes
    • PDAs, Digital Cameras, and Camcorders

    Description

    The MAX1576 charge pump drives up to 8 white LEDs with regulated constant current for uniform intensity. The main group of LEDs (LED1-LED4) can be driven up to 30mA per LED for backlighting. The flash group of LEDs (LED5-LED8) are independently controlled and can be driven up to 100mA per LED (or 400mA total). By utilizing adaptive 1x/1.5x/2x charge-pump modes and very-low-dropout current regulators, the MAX1576 achieves high efficiency over the full 1-cell lithium-battery voltage range. The 1MHz fixed-frequency switching allows for tiny external components, and the regulation scheme is optimized to ensure low EMI and low input ripple.

    The MAX1576 uses two external resistors to set the main and flash full-scale (100%) LED currents. Four control pins are used for LED dimming by either serial control or 2-bit logic per group. ENM1 and ENM2 set the main LEDs to 10%, 30%, or 100% of full scale. ENF1 and ENF2 set the flash LEDs to 20%, 40%, or 100% of full scale. In addition, connect either pair of control pins together for single-wire, serial pulse dimming control.

    The MAX1576 is available in a 24-pin thin QFN, 4mm x 4mm package (0.8mm max height).

    Simplified Block Diagram

    MAX1576: Typical Application Circuit MAX1576: Typical Application 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.