1 Features
1• Boost Converter
– Automotive Grade Product, Q100 Grade-1
Qualified
– Very Wide Input Voltage Range: 4.5 V to 65 V
– Programmable Soft-Start Period
– 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 Regulator
– Programmable LED Current: 50 mA to 250 mA
– 10000:1 Contrast Ratio, 300-ns Minimum
Pulse Width
– 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 PWP, 20-Pin Package

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

3 Description
The LM3492HC/-Q1 device integrates a boost converter and a two-channel current regulator to
implement a highly efficient and cost effective LED
driver. This device drives 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. The nearly constant
switching frequency can be set to a level from 200
kHz to 1 MHz. Ceramic capacitors stabilize the
application circuit and produce no audible noise on
dimming. The programmable peak current limit and
soft-start features reduce current surges at start-up.
An integrated, 190-mΩ, 3.9-A, N-Channel MOSFET
switch minimizes the solution size. The fast slew rate
current regulator allows high frequency and narrow
pulse width dimming signals to achieve a very high contrast ratio of 10000:1. The LED current can be set
from 50 mA to 250 mA by a single resistor.