A Wide-Band Transconductance Amplifier for Current Calibrations

A wide-band transconductance amplifier for current calibrations is described. The amplifier will deliver a ground-referenced constant current of 5 A rms from dc to over 100 kHz. Its stable magnitude and phase permit it to be used in precise power calibration systems to provide the current component of a phantom power source. The amplifier also provides a ground-referenced voltage output of 1 V/A for monitoring the magnitude and phase of the output current.