LM3492 Two-Channel Individual Dimmable LED Driver with Boost Converter and Fast Current Regulator | TI.com

LM3492 (ACTIVE)

Two-Channel Individual Dimmable LED Driver with Boost Converter and Fast Current Regulator

 

Recommended alternative parts

  • LM3492-Q1  -  Automotive qualified version of LM3492

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.

The fast slew rate current regulator allows high frequency and narrow pulse width dimming signals to achieve a very high contrast ratio of 1000:1 at a dimming frequency of more than 3 kHz. The LED current is programmable from 50 mA to 200 mA by a single resistor.

To maximize the efficiency, Dynamic Headroom Control (DHC) automatically adjusts the output voltage to a minimum. DHC also facilitates a single BOM for different number of LED in a string, which is required for backlight panels of different size, thereby reducing overall development time and cost. The LM3492/-Q1 comes with a versatile COMM pin which serves as a bidirectional I/O pin interfacing with an external MCU for the following functions: power-good, overtemperature, IOUT overvoltage and undervoltage indications, switching frequency tuning, and channel 1 disabling. Other supervisory functions of the LM3492/-Q1 include precise enable, VCC undervoltage lockout, current regulator over-power protection, and thermal shutdown protection. The LM3492/-Q1 is available in the thermally enhanced 20-pin HTSSOP package.

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

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Parametrics Compare all products in General lighting LED drivers

 
Input voltage (type)
Vin (Min) (V)
Vin (Max) (V)
Iout (Max) (A)
Vout (Min) (V)
Vout (Max) (V)
Regulated outputs (#)
Topology
Dimming method
Power factor correction (Min)
Type
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Vref (V)
UVLO thresholds on/off (V)
Features
Rating
Operating temperature range (C)
Package Group
Package size: mm2:W x L (PKG)
LM3492 LM3492HC
DC/DC     DC/DC    
4.5     4.5    
65     65    
0.2     0.25    
5     5    
65     65    
2     2    
Boost
Boost with Current Sink
Multi-Channel    
Boost
Boost with Current Sink
Multi-Channel    
PWM     PWM    
   
   
Converter
Inductive
Linear    
Converter
Inductive
Linear    
200     200    
1000     1000    
3.6     3.6    
1.25     1.25    
3.78 / 3.48     4 / 3.7    
Adjustable Switch Frequency
Enable/Shutdown
Integrated Switch
Power Good
Soft Start
Thermal Shutdown    
Adjustable Switch Frequency
Enable/Shutdown
Integrated Switch
Power Good
Soft Start
Thermal Shutdown    
Catalog     Catalog    
-40 to 125     -40 to 125    
HTSSOP | 20     HTSSOP | 20    
20HTSSOP: 42 mm2: 6.4 x 6.5 (HTSSOP | 20)     20HTSSOP: 42 mm2: 6.4 x 6.5 (HTSSOP | 20)    

Design tool

WEBENCH® Designer LM3492

  V in Lower V in Upper
4.5 ≤  V  V ≤ 65.0
Ambient Temp  °C ≤ 125°C
Light Output (optional)  Lumens