1 Features

• Boost Converter:
  • LM3492-Q1 is an Automotive Grade Product That is AEC Q100 Grade 1 Qualified
  • Very Wide Input Voltage Ranged
    From 4.5 V to 65 V
  • Programmable Soft Start
  • No Loop Compensation Required
  • Stable With Ceramic and Other Low ESR Capacitors With No Audible Noise
  • Nearly Constant Switching Frequency Programmable From 200 kHz to 1 MHz
• Current Regulators:
  • Programmable LED Current from 50 mA to 200 mA
  • 1000:1 Contrast Ratio at a Dimming Frequency of More Than 3 kHz, Minimum LED Current Pulse Width is 300 ns
  • Two Individual Dimmable LED Strings up to
    65 V, Total 15 W (Typically 28 LEDs at
    150 mA)
  • Dynamic Headroom Control Maximizes Efficiency
  • Over-Power Protection
  • ±3% Current Accuracy
• Supervisory Functions:
  • Precision Enable
  • COMM I/O Pin for Diagnostic and Commands
  • Thermal Shutdown Protection
  • Thermally Enhanced 20-Pin HTSSOP package

2 Applications

• Ultra-High Contrast Ratio 6.5”-10” LCD Display Backlight up to 28 LEDs
• Automotive or Marine GPS Displays

3 Description

The LM3492/-Q1 integrates a boost converter and a two-channel current regulator to implement a high efficient and cost effective LED driver for driving two individually dimmable LED strings with a maximum power of 15 W and an output voltage of up to 65 V. The boost converter employs a proprietary Projected-On-Time control method to give a fast transient response with no compensation required, and a nearly constant switching frequency programmable from 200 kHz to 1 MHz. The application circuit is stable with ceramic capacitors and produces no audible noise on dimming. The programmable peak current limit and soft-start features reduce current surges at start-up, and an integrated 190 mΩ, 3.9-A N-Channel MOSFET switch minimizes the solution size.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application