Launch of 60V Synchronous 4-Switch Buck Boost LED Driver

Linear Technology Korea (CEO Hong Sa-gwak) has announced the launch of a synchronous buck-boost DC/DC LED controller (product name: LT8391) that regulates LED current from input voltages that are higher than, lower than, or equal to the output voltage.

With an input voltage range of 4V to 60V, the company explains that it is suitable for various applications including automotive, industrial, and architectural lighting. Similarly, the output voltage can be set from 0V to 60V, and it can drive LEDs of various voltage ranges configured in a single string.

The buck-boost controller combined with four external N-channel MOSFETs can deliver 10W to over 100W of LED power. The buck-boost performance of this product is well-suited for automotive and similar applications where input voltage can fluctuate rapidly during shutdown/startup, cold crank, and load dump conditions.

Switching between buck, pass-through, and boost operating modes occurs seamlessly while providing regulated output despite variations in various supply voltages. The LT8391 provides both internal (128:1) and external (2,000:1) LED current PWM dimming using an external high-side PMOS switch. This product is available in a 28-pin 4mm x 5mm QFN or thermally enhanced TSSOP package, realizing a very compact solution footprint.

The LT8391 uses four external N-channel MOSFETs capable of delivering continuous LED current up to 100W with a maximum efficiency of 98%. The 3% current accuracy ensures consistent brightness. The proprietary peak-buck and peak-boost current mode control circuit realizes fixed frequency operation in an adjustable and synchronizable range of 150kHz to 650kHz, or can utilize internal spread spectrum operation for low EMI. Additionally, it includes integrated bootstrap diode and open and short LED protection functions with fault reporting capability.

The LT8391EFE is available in a 28-pin thermally enhanced TSSOP package and the LT8391EUFD is supplied in a 28-pin 4mm x 5mm QFN package. Industrial grade versions LT8391IFE and LT8391IUFD are also available. Pricing is $4.65 per unit based on a quantity of 1,000 units. All versions are available immediately.