Intersil Corporation has released two new radiation-tolerant 36 V instrumentation amplifiers (INAs) with an integrated differential analog-to-digital (ADC) driver for signal-processing applications in communication satellites. While the high-performance amplifier ISL70617SEH offers differential input and rail-to-rail differential output, ISL70517SEH is a rail-to-rail single-ended output version. Both INAs are designed to tolerate a dose level of 75 krad (Si) with a low dose rate exposure of 10 mrad/s. The radiation-tolerant INAs are implemented in the company’s proprietary 40 V complementary bipolar plus JFET (CBiFET) process on bonded silicon-on-insulator substrates to provide single event latch-up and single event burnout robustness of 60 MeV in heavy ion environments. Also, the amplifiers’ single event transient performance of <10 µs eliminates the need for extra filtering.
In comparison to other similar parts on the market, the radiation-tolerant INAs offer higher common-mode rejection ratio (CMRR) and power supply rejection ratio (PSRR) at all gain settings. Typically the INAs are rated for a CMRR and PSRR of 120 dB at gain equal to one. According to the maker, designers can program the amplifier’s gain from 0.1 to 10,000 using two external resistors, and power the input and output stages from different supplies using individual power supply pins. Additionally, by tying the amplifiers’ rail-to-rail outputs to ADC’s low voltage supply, the INA amplifiers protect downstream ICs from high-voltage signals. As a result, they also maintain the ADC’s maximum input dynamic range and eliminate ADC input overdrive.
Operating over a supply range of ±4 V to ±18 V with a differential input voltage range up to ±30 V, the radiation-tolerant amplifiers come in 24-lead ceramic flatpack packages. The operating temperature range for these devices is –55° C to +125° C.