LT86xx High-Voltage Buck Regulators Linear Technology/Analog Devices LT86xx High-Voltage Synchronous Buck Regulators product line features high-performance step-down buck switching regulator ICs. The LT86xx High-Voltage Buck Regulators work from input voltages of 3V up to 100V+, with switching frequencies of up to 4MHz, and high-efficiency operation of up to 96%.