Features and Benefits

  • 1mVp-p Output Voltage Ripple
  • 2.5V to 10V Input Range
  • Uses 0.22µF Capacitors
  • -2V Regulated Output (or Adjustable)
  • 4mA Output Current
  • Surface-Mount Technology

Product Details

The MAX840/MAX843/MAX844 ICs are inverting, charge-pump DC-DC converters with low-noise, regulated outputs. Their low output ripple voltage makes these devices ideal for biasing the GaAsFETs commonly found in cellular telephone transmitters.

The MAX840 evaluation kit (EV kit) is a fully assembled and tested surface-mount board. The board is shipped with a MAX840 mounted, but it can be replaced by the MAX843 or MAX844. Provisions are made for mounting two additional resistors, which are required for output voltages other than -2V. A special scope-probe socket is also mounted on the board, so output noise can be observed on an oscilloscope.


  • Cell Phones
  • Continuously Adjustable GaAsFET Bias
  • GaAsFET Power Amplifier Modules
  • LCD-Bias Contrast Control
  • Personal Communicators, PDAs
  • Regulated Negative Power Supplies
  • Wireless Data Loggers