We have developed a high performance analog electronic device that can be used for the measurement of the inverse spin Hall effect (ISHE) as a function of the applied magnetic field. The electronic circuit is based on the synchronous detection technique with a careful selection of the active components in order to optimize the response in this application. The electronic accessory was adapted for the simultaneous measurement of the ISHE signal and the microwave absorption in an electron spin resonance spectrometer and tested with a bilayer sample of 5 nm of permalloy (Ni80Fe20) and 5 nm of tantalum. The response of the electronic device was characterized as a function of the microwave power, the amplitude and frequency of the modulation signal, and the relative phase between signal and reference. This last characterization reveals a simple method to put in phase the signal with the reference. The maximum signal to noise ratio was achieved for a modulation frequency between 6 and 12 kHz, for the largest possible values of field modulation amplitude and microwave power.