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Adaptive Step-Up Converters with 1.5A Flash Driver

1.5A White LED Flash Driver is Ideal for 5 Megapixel Camera Applications in Cell Phones

Product Details

Key Features

Parametric specs for LED Drivers
VIN (V) (min) 2.5
VIN (V) (max) 5.5
Max. No. of LEDs 3
# LED Channels 3
Regulation Topology Inductor Based
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.75
Dimming Ratio (max) 30
Dimming Control Digital
I2C Serial
POUT (W) 6
ICC (mA) (max) 0.6
LED String Volt. (V) (max) 5.5
Switching Frequency (kHz) 2000
Package/Pins WLP/20
Budgetary
Price (See Notes)
2.17
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Simplified Block Diagram

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Parameters

Parametric specs for LED Drivers
VIN (V) (min) 2.5
VIN (V) (max) 5.5
Max. No. of LEDs 3
# LED Channels 3
Regulation Topology Inductor Based
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.75
Dimming Ratio (max) 30
Dimming Control Digital
I2C Serial
POUT (W) 6
ICC (mA) (max) 0.6
LED String Volt. (V) (max) 5.5
Switching Frequency (kHz) 2000
Package/Pins WLP/20
Budgetary
Price (See Notes)
2.17

Key Features

  • 2.5V to 5.5V Operation Range
  • Step-Up DC-DC Converter
    • 1.5A Guaranteed Output Current
    • Adaptive or I²C Programmable Output Voltage
    • 2MHz and 4MHz Switching Frequency Options
  • Two Flash/Movie LED Current Regulators
    • I²C Programmable Flash and Movie Current
    • Low-Dropout Voltage (110mV max) at 500mA
  • LED Indicator Current Regulator
    • I²C Programmable Output Current
    • Ramp and Blink Timers for Indicator Mode
    • Low-Dropout Voltage (130mV max) at 16mA
  • I²C Programmable Safety and Watchdog Timers
  • GSM Blank Logic Input
  • MAXFLASH System Lockup Protection
  • Remote Temperature Sensor Input
  • Open/Short LED Detection
  • Thermal Shutdown Protection
  • < 1µA Shutdown Current
  • 20-Bump, 0.5mm Pitch, 2.5mm x 2.0mm WLP

Applications/Uses

  • Cell Phones and Smart Phones
  • PDAs, Digital Cameras, and Camcorders

Description

The MAX8834Y/MAX8834Z flash drivers integrate a 1.5A PWM DC-DC step-up converter and three programmable low-side, low-dropout LED current regulators. The step-up converter features an internal switching MOSFET and synchronous rectifier to improve efficiency and minimize external component count. An I²C interface provides flexible control of stepup converter output voltage setting, movie/flash mode selection, flash timer duration settings, and current regulator settings. The MAX8834Y/MAX8834Z operate down to 2.5V, making them future proof for new battery technologies.

The MAX8834Y/MAX8834Z consist of two current regulators for the flash/movie mode. Each current regulator can sink 750mA in flash mode and 125mA in movie mode. The MAX8834Y/MAX8834Z also integrate a 16mA low-current regulator that can be used to indicate camera status. The indicator current regulator includes programmable ramp and blink timer settings. A programmable input current limit, invoked using the GSMB control, reduces the total current drawn from the battery during PA transmit events. This ensures the flash current is set to the maximum possible for any given operating condition. Additionally, the MAX8834Y/MAX8834Z include a MAXFLASH function that adaptively reduces flash current during low battery conditions to help prevent system undervoltage lockup.

Other features include an optional NTC input for finger-burn protection and open/short LED detection. The MAX8834Y switches at 2MHz, providing best overall efficiency. The MAX8834Z switches at 4MHz, providing smallest overall solution size. The MAX8834Y/MAX8834Z are available in a 20-bump, 0.5mm pitch WLP package (2.5mm x 2.0mm).

Simplified Block Diagram

MAX8834, MAX8834Y, MAX8834Z: Typical Operating Circuit MAX8834, MAX8834Y, MAX8834Z: 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 .