Maxim launches step-down regulator with internal switch

Maxim Integrated Products has introduced the MAX8723, a high-efficiency, switch-mode, step-down regulator with a 14V internal power switch. With only a few external passive components, Maxim said this low-cost regulator can generate a fixed 3.3V or adjustable DC output voltage (dual mode) from a 6V to 13.2Vdc source. The 13.2V input voltage makes this device suitable for LCD displays, point-of-load regulators and other 8V/12V industrial-equipment applications.

The new regulator can deliver up to 2A. It features an internal power MOSFET, a built-in bootstrap diode for its MOSFET driver, and an interface for an external synchronous-rectifier MOSFET driver to replace the Schottky diode and improve efficiency, the company said. Its fixed-frequency PWM/skip-mode operation and current-mode control architecture promise fast load-transient response without compensation. The switching frequency is a pin-selectable 500kHz, 1MHz or 1.5MHz, Maxim said, which minimizes the size of external components.

The device has a built-in soft-start function that limits inrush current during startup. This avoids transients that can trigger the front-end protection circuit and lock up the system. The device also features three other important shutdown functions: current-limit, thermal-shutdown and timer-delayed output-fault. These functions protect the power supply against fault conditions.

The new device also includes a linear regulator (VL) that provides a fixed 5V output (25mA) to support small external loads. The reference output is highly precise (2V ±1 percent), and can also supply small external load currents.

The MAX8723 is available in a 16-pin, 4-by-4mm TQFN package and operates over the -40°C to 85°C industrial temperature range. Prices start at $3.65 (1,000-up, FOB USA). A preassembled MAX8723 EV kit is available (with recommended external components) to reduce design time.