Synchronous Rail-to-Rail Single Resistor, ±5A Sink/Source in 0V ~ 14.5VOUT Voltage Range

Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of a high-efficiency current-mode synchronous buck regulator with ±5A output (product name: LTC3623).

This product enables output voltage adjustment from 14.5V down to 0V with a single resistor. Based on Linear Technology's excellent linear regulators and switching regulators, this innovative architecture uses a 50µA current reference along with a single resistor to set the output voltage. The product also enables easy current sharing among multiple regulators through its unique design approach, allowing output voltage setting for all regulators with a single external resistor.

The LTC3623 provides bipolar ±5A sink and source capability, wide input and output voltage (VIN and VOUT) range, current-mode control for tight line and load regulation, high efficiency, minimal external component count, and parallel capability, making it ideal for modern multi-rail systems including tracking supplies, portable devices, distributed power supply systems, battery-powered equipment, and thermoelectric cooling systems.

The LTC3623 features a wide input voltage range of 4V to 15V, making it ideal for dual-cell lithium-ion applications and fixed 5V to 12V intermediate bus systems. Additionally, the low RDS(ON) integrated N-channel power MOSFET and synchronous rectification characteristics deliver high efficiency reaching 96%.

This device incorporates a new design approach that dynamically adjusts the output voltage within the range of 0V to VIN ~ 0.5V, providing virtually rail-to-rail performance. The LTC3623 can sink down to a minimum of 0VOUT at maximum 5A, enabling individual rail power shutdown in the system when needed. The on-chip trimmed reference features exceptional accuracy of ±1%.

Furthermore, output regulation and transient voltage are independent of the output voltage. Users can directly drive the LTC3623's ISET pin using an external voltage supply to program the converter's output voltage. Additionally, output voltage tracking or soft start can be easily programmed through the ISET pin for applications requiring power sequencing.

The LTC3623 offers a switching frequency range of 400kHz to 4MHz, allowing use of ultra-compact, low-cost capacitors and inductors, and comes in a compact QFN package, providing a very compact solution footprint for multi-rail applications. Other features include programmable wire-drop compensation, input supply voltage regulation loop for power extraction from high-impedance sources such as solar panels, output current monitor, power-good voltage monitor, external synchronization capability, and thermal protection.

The LTC3623 is offered in a thermally enhanced 24-pin 3mm x 5mm QFN package, with E and I grades featuring an operating junction temperature range of 40°C to 125°C. Product inventory is currently available, and the E grade pricing starts at $3.95 per unit based on quantities of 1,000 units.