Maxim Introduces New Step-Down Regulator with Internal Switch for LCD Displays
Maxim Integrated Products Inc. introduced the MAX8723, a high-efficiency, switch-mode, step-down regulator with a 14V internal power switch. With only a few external passive components, 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 range makes this part ideal for LCD displays, point-of-load regulators, and other 8V/12V industrial-equipment applications.
The MAX8723 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 drive to replace the Schottky diode and improve efficiency. Its fixed-frequency PWM/skip-mode operation and current-mode control architecture provide fast load-transient response without compensation. The switching frequency is a pin-selectable 500kHz, 1MHz, or 1.5MHz, which minimizes the size of external components.
The MAX8723 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 MAX8723 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%), and can also supply small external load currents.
The MAX8723 is available in a 16-pin, 4mm x 4mm TQFN package and operates over the -40°C to +85°C industrial temperature range. Prices start at $3.65 (1000-up, FOB USA). A preassembled MAX8723 EV kit is available (with recommended external components) to reduce design time.
