The ISL97691 is Intersil’s highly integrated 4 channel LED driver

for single cell Li-Ion battery operated mobile displays requiring

analog dimming, and for 3D mobile display applications. It drives

four 40mA channels of LEDs up to 26V from an input supply 2.4V

to 5.5V. The ISL97691 will also drive 60mA channels up to 21V at

30 duty for high peak current 3D modes.

The ISL97691 provides 4 channels of current with 2 independent

analog dimming controls and 2 independent PWM dimming

controls. Channels 1 and 2 form one channel group and channels

3 and 4 form the other channel group. Each channel group’s

analog dimming is controlled through 1-Wire communication

with 6-bit resolution and each channel group’s PWM dimming is

controlled by a separate PWM input. This unique setup allows 2D

or 3D application where independent and dynamic channel

control of LED peak current and PWM dimming duty cycle are

possible. The ISL97691 employs adaptive boost architecture that

allows ultra low dimming duty cycle as low as 0.005 at 100Hz

dimming frequency.

The driver features dynamic headroom control that monitors the

highest LED forward voltage string and uses its feedback signal

for the minimum output regulation.

The ISL97691 incorporates extensive protection functions

including string open and short circuit detections, OVP, and OTP.

The switching frequency can be adjusted from 400kHz to 1.5MHz.

The device is offered in a 16 Ld TQFN 3x3mm package and can

operate in ambient temperature from -40°C to +85°C.

Features

• 2.4V Minimum input voltage, no need for higher voltage

supplies

• 4 x 60mA (Note 1) and 4 x 40mA (Note 2) LED current

• 2 Groups of independent analog and pwm current controls

- 1-Wire interfaces for 6-bit analog dimming

- PWM inputs for PWM dimming

- 0.005 Minimum PWM dimming duty cycle at 100Hz

• Low 0.8mA quiescent current

• ±2.5 current matching

• Adjustable switching frequency from 400kHz to 1.5MHz

• Fault protection

- OVP, OTP, channel open/short circuit protections

Applications

• Tablet, notebook PC and smart phone displays LED

backlighting

• Mobile displays for 2D or 3D LED backlighting