MAX1575

White LED 1x/1.5x Charge Pump for Main and Sub-Displays

First 85% Efficient, Fractional, White-LED Charge Pump with Dual, Single-Wire Dimming Control for Main and Sub-Displays


Please check latest availability status for a specific part variant.

Description

The MAX1575 charge pump drives up to four white LEDs in the main display and up to two white LEDs in the sub-display with regulated constant current for uniform intensity. By utilizing adaptive 1x/1.5x charge-pump modes and very-low-dropout current regulators, it achieves high efficiency over the full 1-cell lithium-battery input voltage range. A 1MHz fixed-frequency switching allows for tiny external components, and the regulation scheme is optimized to ensure low EMI and low input ripple.

The MAX1575 uses an external resistor to set the full-scale 100% LED current. Two enable inputs, ENM and ENS, are used for simple on/off controls for the main and sub-displays, respectively. By repeatedly pulsing either enable input, the LEDs can be dimmed in multiple steps down to 5%. Once the desired brightness is set, the MAX1575 maintains that brightness setting as long as the enable input is kept high. If an enable input is kept low for more than 2ms, the LED current for the respective display is set to zero. If both enable inputs are kept low for more than 2ms, the MAX1575 enters shutdown.

The MAX1575 is available in a 16-pin 4mm x 4mm thin QFN package (0.8mm max height).
MAX1575: Typical Operating Circuit MAX1575: Typical Operating Circuit Enlarge+

Key Features

  • Powers Main and Sub-Display LEDs
  • 85% Average Efficiency (PLED / PBATT) Over Li+ Battery Discharge
  • 2% LED Current Matching
  • Up to 30mA/LED Drive Capability
  • Adaptive 1x/1.5x Mode Switchover
  • Low Input Ripple and EMI
  • Individual 5% to 100% Dimming Through Single-Wire Serial Pulse Interface
  • Low 0.1µA Shutdown Current
  • 2.7V to 5.5V Supply Voltage Range
  • Soft-Start Limits Inrush Current
  • Output-Overvoltage Protection
  • Thermal-Shutdown Protection
  • 16-Pin Thin QFN 4mm x 4mm Package

Applications/Uses

  • Cell Phones with Main and Sub-Displays
  • PDAs/Smartphones with Up to Six White LEDs

Technical Documents

Reference Schematic 1804 Driving LEDs in Battery-Operated Applications: Controlling Brightness Power Efficiently

Quality and Environmental Data

Request Reliability Report for: MAX1575 
Lead-Free Package Tin (Sn) Whisker Reports
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

 
Status:
Package:
Temperature:

Related Resources


MAX25024
Automotive Low Input Voltage I2C 4-Channel 150mA Backlight Driver Supporting ASIL B

  • Wide Voltage-Range Operation
  • High Integration
  • Robust and Low EMI

MAX25613
Automotive Infrared LED Controller

  • High-Current LED Driver with Reduced di/dt on the Battery Harness
  • Protection Features Increase System Reliability
  • Automotive Ready

MAX25601C
Synchronous Boost and Synchronous Buck LED Controllers

  • Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Cost
  • Wide Dimming Ratio Allows High Contrast Ratio
  • Protection Features and Wide Temperature Range Increase System Reliability

MAX25601D
Synchronous Boost and Synchronous Buck LED Controllers

  • Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Cost
  • Wide Dimming Ratio Allows High Contrast Ratio
  • Protection Features and Wide Temperature Range Increase System Reliability

MAX25601A
Synchronous Boost and Synchronous Buck LED Controllers

  • Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Cost
  • Wide Dimming Ratio Allows High Contrast Ratio
  • Protection Features and Wide Temperature Range Increase System Reliability

MAX25601B
Synchronous Boost and Synchronous Buck LED Controllers

  • Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Cost
  • Wide Dimming Ratio Allows High Contrast Ratio
  • Protection Features and Wide Temperature Range Increase System Reliability

MAX20056B
Integrated, 6-Channel High-Brightness LED Driver with Very Wide PWM Dimming Ratio and Phase Shifting for Automotive Displays

  • Robust with Respect to EMC and Automotive Battery Transients
  • Spread-Spectrum Mode Reduces Emission at the Switching Frequency and its Harmonics
  • Phase-Shift Dimming of LED Strings

MAX25612
Automotive Synchronous High Voltage LED Controller

  • Integration Minimizes BOM and Cost
  • Simple to Optimize for Efficiency, Board Space, and Input Operating Range
  • Protection Features Increase System Reliability