The ST1843 and ST1845 from STMicroelectronics are industry-standard pwm controllers that have been used over the years in a number of missions being Single Event Latch-up (SEL) free and granting immunity, respectively, to 50 and 100 krad Total Ionization Dose (TID), with hundreds of them still flying. This reliable work-horse of power converter designs has successfully passed a full qualification protocol and is now ESCC qualified.
These controllers provide a solution for the implementation of off-line or dc-dc fixed-frequency current mode control schemes with a minimal external parts count. Radiation hardness and hermetic packaging makes it them well-suited choice for aerospace and other harsh environments.
Key features include: Oscillator frequency guaranteed at 250kHz; Trimmed oscillator for precise frequency control; Current mode operation to 500kHz automatic feed forward compensation; Latching pwm for cycle-by-cycle current limiting; Internally trimmed reference with undervoltage lockout; High current totem pole output; Undervoltage lockout with hysteresis; Low start-up and operating current; Hermetic package; 50 and 100 krad (Si); and SEL free at 120 MeV/cm2/mg at 125 degrees C.
