GENERAL DEscriptION

The SGM3122 is a current-regulated white LED driver with integrated low dropout current sources and a high efficiency charge pump. The charge pump has 1×/1.5× fractional operation mode. The SGM3122 is designed for LCD display backlight applications.

The supply voltage operates from 2.7V to 5.5V and is well suited for various applications powered by a 1-cell Li-Ion battery, as well as 3-cell or 4-cell NiCd, NiMH or Alkaline batteries.

The ISET reference current is set through an external resistor on the ISET pin. The SGM3122 supports up to 4 LED strings for total maximum 120mA current. In addition, the charge pump with current control reduces input current ripple and ensures low EMI. Low capacitance makes the SGM3122 ideal for small battery-powered applications.

The SGM3122 is available in a Green TQFN-3×3-16L package. It operates over an ambient temperature range of -40℃ to +85℃.

FEATURES

• Input Voltage Range: 2.7V to 5.5V

• Support up to 4 LEDs at 30mA Each

• LED Brightness Control through PWM Signal

• 1× and 1.5× Charge Pump for High Conversion Efficiency

• Switching Frequency: 1MHz

• 0.5% Regulated Output Current Matching

• Built-in Soft-Start for Reducing Inrush Current

• Low Input Ripple and Low EMI

• Protection Features

  Over-Current Protection

  Under-Voltage Lockout

  Thermal Shutdown

• Available in a Green TQFN-3×3-16L Package

APPLICATIONS

Cellular Phones, Smart Phones

Digital Cameras, Camcorders, PDAs

Handheld PCs

Keypad Backlight