The TPS6734 is a fixed 12-V output boost converter capable of delivering 120 mA from inputs as low as3.75 V. The device is pin-for-pin compatible with the MAX734 regulator and offers the following advantages: lower supply current, wider operating input-voltage range, and higher output currents. As shown in Figure 1, the only external components required are: an inductor, a Schottky rectifier, an output filter capacitor, an input filter capacitor, and a small capacitor for loop compensation. The entire converter occupies less than 0.7 in2of PCB space when implemented with surface-mount components. An enable input is provided to shut down the converter and reduce the supply current to 3 uA when 12 V is not needed.

The TPS6734 is a 170-kHz current-mode PWM ( pulse-width modulation) controller with an n-channel MOSFET power switch. Gate drive for the switch is derived from the 12-V output after start-up to minimize the die area needed to realize the 0.7-MOSFET and improve efficiency at input voltages below 5 V. Soft start is accomplished with the addition of one small capacitor. A 1.22-V reference (pin 2) is brought out for external use.

High efficiency at low supply voltages and low supply current in shutdown make the TPS6734 particularly attractive for flash memory programming supplies, PCMCIA cards, and operational amplifiers in battery-powered equipment. The TPS6734 is available in 8-pin DIP and SOIC packages and operates over a free-air temperature range of -40°C to 85°C.Read more