TPS60140

The TPS6014x step-up, regulated charge pumps generate a 5-V ±4% output voltage from a 1.8-V to 3.6-V input voltage range. The devices are typically powered by two alkaline, NiCd, or NiMH battery cells and provide an output current of minimum 100 mA from a 2-V input. Only four external capacitors are needed to build a complete voltage tripler charge pump.

The devices regulate the output by using the pulse-skip topology. The controller is optimized for lowest output voltage ripple over the complete output current range. The output peak current and therefore the output voltage ripple are drastically reduced compared to a conventional pulse-skip topology by regulating the charge pump output resistance. At light loads the maximum output resistance is limited to assure a low quiescent current.

The TPS60140 includes a low-battery comparator that issues a warning if the battery voltage drops below a user-adjustable threshold voltage. The TPS60141 features a power-good output that goes active when the output voltage reaches 90% of its nominal value.

The logic shutdown function disables the converter, reduces the supply current to a maximum of 1 µA and disconnects the output from the input. Special current-control circuitry prevents excessive current from being drawn from the battery during start-up. This DC/DC converter requires no inductors, therefore, EMI is of little concern. The TPS6014x operates over a free-air temperature range of –40°C to 85°C. It is available in the small, thermally enhanced 20-pin HTSSOP package (PWP).