LM3492HC-Q1 Datasheet, PDF (1/29 Pages) Texas Instruments – Two-Channel, Individual Dimmable LED Driver

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LM3492HC-Q1, LM3492HC
SNVS797B – MARCH 2012 – REVISED OCTOBER 2015
LM3492HC/-Q1 Two-Channel, Individual Dimmable, LED Driver
With Boost Converter and Fast Current Regulator
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.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM3492HC
LM3492HC-Q1
PWP (20)
6.50 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Application
L1
C_IN
C_CDHC
C_VCC
R_COMM
LM3492HC
LM3492HC-Q1
VIN
SW
CDHC
VCC
EN
RT
VOUT
FB
PGND
IREF
GND
ILIM
COMM
LGND
DIM1/CLK IOUT1
DIM2
IOUT2
R_RT
R_IREF
C_FB
R_FB1
C_OUT
R_FB2
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.