Femto Messtechnik GmbH has introduced an ultralow-noise variable gain current transimpedance amplifier for sensitive current and charge measurements. The DDPCA-300 has a switchable gain from 104 to 1013 V/A and a dynamic range of 240 dB. Peak-to-peak noise is 0.4 fA, enabling measurement of currents in the femto to pico ampere range. Features include adjustable voltage directly on the amplifier input for device-under-test biasing, a DC optimized design with high stability and low drift, manual control and a remote interface. Packaged in a miniature and rugged aluminum housing designed to optimize electromagnetic interference shielding, the device has applications including spectroscopy, photodiode and charge detector amplification, sensitive ionization, conductive atomic force microscopy, quantum and biotechnology experiments, and preamplification for oscilloscopes, analog-to-digital converters and digital voltmeters.