PMIC integrates display power & backlight LED driver

18th August 2014

Nat Bowers

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Increasing smartphone battery life by an hour or more, the ISL98611 power management IC integrates the display power and backlight LED driver functions in a single chip. Significantly improving the efficiency of both functions, Intersil's PMIC also improves display brightness uniformity and colour consistency.

Generating two output rails at +5 and -5V, the ISL98611 integrates a boost regulator, LDO, inverting charge pump and a boost regulator with 3-channel current sinks for the LED backlight driver.

The backlight LEDs and display power can consume the majority of a smartphone's battery power. The ISL98611 backlight LED driver can deliver up to 93% efficiency. Using a 2.5x2mm² inductor, the device generates ±5V display power supplies with greater than 88% efficiency at 15mA load. Claimed to use 24% less PCB area compared to competing devices, the PMIC requires only eight external devices and therefore enables the phone to house a larger battery.

The ISL98611 provides excellent LED current matching at very low LED current, achieving ±2.2% matching down to 1mA and ±2.8% at 50μA. The device also includes hybrid dimming to eliminate white LED colour shift issues at low LED current.

Andrew Cowell, Senior Vice President, Mobile Power Products, Intersil, commented: “With each new product generation, smartphone designers are challenged to add more features, reduce size and extend battery life. The ISL98611 delivers the integration, extended battery life and display image quality improvement our customers want in their next-generation smartphone designs.”

Available now in a 2.33x2.61mm², 30-ball WLCSP, the ISL98611 display power and LED driver is priced from $1.50 in 1,000 unit quantities. Intersil also offers the ISL98611EVAL1Z evaluation board for $100 each.