The MCP1253-33X50 and MCP1253-ADJ are inductorless, positive regulating, low noise charge pump DC-to-DC converters. The MCP1253-33X50 has selectable outputs of either 3.3 or 5.0 V, while the MCP1253-ADJ has an adjustable output between 1.5 and 5.5 V. Both can deliver 120 mA of load current at the selected regulated output voltage. Since the device incorporates an automatic buck/boost feature, it will maintain the regulated output voltage whether the input voltage is above or below the output voltage. These charge pumps operateat a switching frequency of 1 MHz (reducing capacitor sizes), and feature power saving shutdown pins, short circuit protection, thermal shutdown, and power-good pins that report out-of-regulation conditions.

  Wide 2.1 to 5.0V input range

  Fixed, regulated 3.3 V, 5.0 V, or adjustable (1.5 to 5.5 V) outputs

  Supplies regulated output voltages for up to 120 mA loads

  Low 60 µA supply current in no load conditions

  High 2.5% voltage accuracy (on fixed voltage outputs)

  High 1 MHz operation to aoivd interference with IF bands and allows for small capacitor use to save board space and cost

  Logic level shutdown control reduces current consumption to 0.1 µA during standby operation

  Power-good output indicator with hysteresis

  Thermal shutdown protection with hysteresis

  Short circuit protection

  Soft-start circuitry to minimize inrush current

  -40 ºC to +85 ºC operation