ISL97686

4-Channel LED Driver with Independent Channel Control for Dynamic Dimming

Product Status: Mass Production(*)

OVERVIEW

The ISL97686 is a PWM controlled LED driver that supports 4 channels of LED current, for Monitor and TV LCD backlight applications. It is capable of driving 160mA per channel from a 9V to 32V input supply, with current sources rated up to 75V absolute maximum.

The ISL97686’s current sources achieve typical current matching to ±1%, while dynamically maintaining the minimum required VOUT necessary for regulation. This adaptive scheme compensates for the non-uniformity of forward voltage variance in the LED strings.

The ISL97686 dimming can be controlled by a high speed SPI interface for independent channel control for dynamic dimming function synthesized on chip at 10-bit resolution.

The ISL97686 has an advanced dynamic headroom control function, which monitors the highest LED forward voltage string, and regulates the output to the correct level to minimize power loss. This proprietary regulation scheme also allows for extremely linear PWM dimming from 0.02% to 100%. The LED current can also be switched between two current levels, giving support for 3D applications. The ISL97686 incorporates extensive protections of string open and short circuit detections, OVP, and OTP.

KEY FEATURES

  • 4 x 160mA, 75V rated channels with integrated channel regulation FETs
  • Channels can be ganged for high current
  • 2 x 350mA
  • 1 x 700mA
  • 9V~32V input voltage
  • Dimming modes:
  • Independent channel dimming control with SPI
  • PWM Dimming with adjustable output frequency
  • 10-bit dimming resolution
  • VSYNC mode
  • 2 selectable current levels for 3D applications
  • Current matching of ±1%
  • Integrated fault protection features such as string open circuit protection, string short circuit protection, overvoltage protection, and over-temperature protection
  • 28 Ld 5x5mm TQFN and 28 Ld 300mil SOIC packages available

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL97686
Basic Information
Production Status
Mass Production(*)
# of Devices/ Channels
4
Total Current for DC/DC Lighting (mA)
700
Output Current Max/Channel (mA)
160
Output Voltage Max (V)
75
Brightness Control
PWM or LED DC current control
Bus/Output Interface
SPI
Input Voltage Max (V)
32
Input Voltage Min (V)
9
Backlight for LCD Size (min) (in)
0
Backlight for LCD Size (max) (in)
29
Qualification Level
Standard
Peak Efficiency (%)
90
# of LEDs (max)
4-Channel 75V 160mA LED Driver
Frequency
0.2, 0.6, 1.2 MHz
IS (max)
5.5 mA
IQ (max)
5 µA
ISW (typ) (mA)
3400
Integrated Diode
Yes
Over Voltage Protection
Yes
Fault Switch
Yes
Topologies
Inductor Boost
Input Voltage Range (V)
9 to 32
Backlight for LCD Size
up to 29
Temperature Range
-40 to +105

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