4 Radiation Effects

Along with DC and AC regulation, we recommend you consider any radiation effects introduced by the converter to meet the tolerance requirements from the XQRKU060. These radiation effects include total ionizing dose (TID) and single-event transients (SETs).

TID could introduce drift in the internal reference of the converter that could affect DC regulation. The TPS7H4001-SP is rated up to 100 krad(Si), and Texas Instruments tests every specification to meet the data sheet limits after exposure to 100 krad(Si). The internal reference of the TPS7H4001-SP shows very little sensitivity to TID, with a maximum drift of 2 mV (~0.3%) at 100 krad(Si).

Transients induced by heavy ions (SETs) are not as predictable as TID and could have a very negative effect on regulation. A converter sensitive to transients that shuts down the output of the converter or exceeds the maximum regulation requirements of the XQRKU060 could severely compromise the performance of the FPGA. Additionally, large and positive transients could potentially damage the FPGA.

The TPS7H4001-SP is fully characterized for SETs up to a linear energy transfer (LET) equal to 75 MeV-cm2/mg and shows resilient performance with a low number of SETs (<10 at PVIN = 5 V, VIN = 5 V) when the output voltage exceeds ±3% at a fluency of 10 million ions/cm2 (see the Single Events Effects Test Report of the TPS7H4001-SP for details). This translates to a very low SET cross-section of 2.18 × 10-7 cm2/device (PVIN = 5 V, VIN = 5 V). This SET performance, along with its TID rating of 100 krad(Si), makes the TPS7H4001-SP a reliable converter to power up the XQRKU060.