Triple Output LED Driver Drives Up to 30 x 300mA LEDs & Offers 3000:1 True Color PWM Dimming
Linear Technology Corporation announces the LT3492, a 2.1MHz DC/DC converter designed to operate as a three-channel constant current LED driver. Each of the LT3492’s three channels can drive up to ten 300mA LEDs in series, enabling it to drive up to 30 x 300mA LEDs at efficiencies up to 96%.
All three channels are operated by an independent True Color PWM™ signal, enabling each to be dimmed independently to ratios as high as 3,000:1. A fixed frequency, current mode architecture ensures stable operation over a wide range of supply and output voltages. A frequency adjust pin enables the user to program the frequency between 330kHz and 2.1MHz to optimize efficiency while minimizing external component size. The LT3492’s thermally enhanced 4mm x 5mm QFN (or thermally enhanced TSSOP) package provides a highly compact solution footprint for up to 50W LED applications.
The LT3492 senses output current at the high side of the LED, enabling buck, buck-boost or boost configurations. With an external sense resistor, the user can program the output current range of each channel. Each of the three independent driver channels utilizes an internal 600mA, 60V NPN switch and has a built-in gate driver for PMOS disconnect. Other features include open LED protection and thermal limiting.
Typical Applications:
• RGB Lighting
• Billboards and Large Displays
• Automotive and Avionic Lighting
• Constant-Current Sources
Summary of Features: LT3492
• True Color PWM™ Dimming Delivers up to 3000:1 Dimming Ratio
• Built-In Gate Driver for PMOS LED Disconnect
• Three Independent Driver Channels with 600mA, 60V Internal Switches
• Operates in Buck, Boost & Buck-Boost Modes
• Wide Input Voltage Range: Operation from 3V to 30V, Transient Protection to 40V
• CTRL Pin Accurately Sets LED Current Sense Threshold over a Range of 10mV to 100mV
• Adjustable Frequency: 330kHz to 2.1MHz
• Open LED Protection
• 28-Lead (4mm × 5mm) QFN & TSSOP Packages
The LT3492EUFD is available in a thermally enhanced 28-lead 4mm x 5mm QFN package, and the LT3492EFE is available in a thermally enhanced TSSOP-28 package. Pricing starts at $3.70 and $3.85 each, respectively in 1,000 piece quantities. Industrial grade versions, the LT3492IUFD and LT3492IFE, are tested and guaranteed to operate from -40°C to 125°C operating junction temperature and are priced at $4.35 and $4.53 each, respectively in 1,000 piece quantities. All versions are available from stock. For more information, visit www.linear.com.
