The TPS6735 is a fixed negative 5-V output inverting dc/dc converter capable of delivering 200 mA from inputs as low as 4.5 V. The only external components required are an inductor, an output filter capacitor, an input filter capacitor, a reference filter capacitor, and a Schottky rectifier. An enable input is provided to shut down the inverter when a -5-V output is not needed. The typical supply current is 1.9 mA at no-load and is further reduced to 1-uA when the enable input is low.

The TPS6735 is a 160-kHz current-mode pulse-width-modulation (PWM) controller with a p-channel MOSFET power switch. The gate drive uses the -5-V output to reduce the die area needed to realize the 0.4- MOSFET. Soft start is accomplished with the addition of one small capacitor at SS. A 1.22-V reference is available for external loads up to 125 uA.

The TPS6735 is attractive for board-level dc/dc conversion in computer peripherals and in battery-powered equipment requiring high efficiency and low supply current.

The TPS6735 is available in 8-pin DIP and SOIC packages and operates over a free-air temperature range of -40°C to 85°C.

• Negative 5-V 200-mA Output (VCC >= 4.5 V)
• \x95 4-V to 6.2-V Input Operating Range
• \x95 78% Typical Efficiency
• \x95 160-kHz Fixed-Frequency Current-Mode PWM Controller
• \x95 EN Input Inhibits Operation and Reduces Supply Current to 1 uA
• \x95 Soft Start
• \x95 8-Pin SOIC and DIP Packages
• \x95 -40°C to 85°C Free-Air Temperature Range
• \x95 Pin-for-Pin Compatible with MAX735