The ISL70591SEH, ISL73591SEH, ISL70592SEH, and ISL73592SEH are radiation hardened precision 100µA and 1mA current source ICs. The devices have excellent accuracy of ±1% over a wide operating voltage range of 3V to 40V and over a temperature range of -55 °C to +125 °C. Fabricated with the Renesas proprietary PR40 Silicon On Insulator (SOI) process, the devices are immune to single event latch-up. The high output impedance of the devices makes them insensitive to voltage drops across long lines. They can withstand a forward operating voltage of 40V and a reverse voltage of -0.5V. The ISL7x591SEH and ISL7x592SEH are two terminal floating current sources allowing them to be used in high-side, low-side, and dual-side load applications such as sensor excitation, biasing networks, low voltage references, floating voltage references, and ramp generators. The current sources were primarily designed for thermistor and other sensor excitation applications widely used in space crafts. The ISL7x591SEH and ISL7x592SEH are available in a 4 Ld ceramic flatpack and die forms. The temperature range is -55 °C to +125 °C.


  • Electrically screened to DLA SMD 5962-18217
  • Wide operating voltage range: 3V to 40V
  • High initial accuracy (+V = 20V at +25 °C): ISL7x591SEH: ±0.34%, ISL7x592SEH: ±0.30%
  • High output impedance: ISL7x591SEH: 189MΩ (typical), ISL7x592SEH: 14MΩ (typical)
  • Completely floating: No ground connection
  • Radiation acceptance testing - ISL70591SEH and ISL70592SEH
    • High dose rate (50-300rad(Si)/s): 100krad(Si)
    • Low dose rate (0.01rad(Si)/s): 75krad(Si)
  • Radiation acceptance testing - ISL73591SEH and ISL73592SEH: Low dose rate (0.01rad(Si)/s): 75krad(Si)
  • SEE hardness
    • No SEB/SEL LETTH, +V = 35V: 86MeV•cm2/mg
    • SET duration (time recovery) ≤ 125µs




  • Sensor excitation
  • Biasing network
  • Low voltage references
  • Ramp generators


Type Title Date
Datasheet PDF 780 KB
Brochure PDF 5.02 MB
Report PDF 225 KB
Manual - Development Tools PDF 538 KB
Report PDF 342 KB
Report PDF 716 KB
White Paper PDF 533 KB
Application Note PDF 338 KB
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