Single-chip display power and LED driver for smartphones delivers higher power efficiency - Embedded.com

Single-chip display power and LED driver for smartphones delivers higher power efficiency

The ISL98611 display power and LED driver for smartphones from Intersil Corporation is the first power management IC that integrates the display power and backlight LED driver functions in a single chip. It significantly improves efficiency of both functions to increase smartphone battery life by an hour or more.

The ISL98611 also improves display brightness uniformity and color consistency. The highly integrated IC has a boost regulator, LDO, and inverting charge pump for generating two output rails at +5V and -5V in a single device. It also includes a boost regulator with 3-channel current sinks for the LED backlight driver. This single-chip solution offers designers four key benefits:

  • Extended battery life: When used for web browsing and emails, a smartphone’s backlight LEDs and display power consume the majority of its battery power. The ISL98611 backlight LED driver delivers seven percent higher efficiency (up to 93 percent) than competitive multi-chip solutions and generates +/-5V display power supplies with greater than 88 percent efficiency at 15mA load using a 2.5x2mm2 size inductor, compared to 85 percent efficiency of the nearest competitor.
  • Improved display uniformity: The ISL98611 provides excellent LED current matching at very low LED current: it achieves +/- 2.2 percent matching down to 1mA and +/- 2.8 percent at 50µA.
  • Improved display color consistency: The ISL98611 includes hybrid dimming to eliminate white LED color shift issues at low LED current, which occur with DC dimming.
  • Smallest footprint: The ISL98611’s total display power plus backlight solution uses 24 percent less PCB area compared to the competition, while requiring only eight external components. This provides additional space to house the phone’s battery.

Features and Specifications:

  • Powers two or three strings of backlight LEDs with up to 93 percent efficiency
  • Generates +/-5V display power supplies with 88 percent efficiency at 15mA load using a 2.5x2mm2 size inductor
  • Analog, PWM and hybrid dimming
  • +/-2.2 percent current matching down to 1mA and +/-2.8 percent at 50µA
  • 2.5V to 5V input voltage range
  • VP and VN output adjustable from +/4.5V up to +/-6V with 50mV steps
  • I2C, adjustable output voltage settings
  • 1uA shutdown supply current

More information

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