SBAS932 March 2024 DAC39RF10-SEP , DAC39RF10-SP , DAC39RFS10-SEP , DAC39RFS10-SP
PRODMIX
Careful consideration must be given to the environmental conditions when using a product in a radiation environment. Table 8-2 provides a summary of radiation tolerance for device features.
Feature | Radiation Tolerance |
---|---|
Writable SPI registers (excluding write-to-clear registers) |
Implemented with upset immune flip flops. Radiation does not alter the state. |
Read-only SPI registers that return constant values | Radiation does not alter the state (that is, CHIP_TYPE, CHIP_ID, CHIP_VERSION, VENDOR_ID) |
Read-only SPI status registers associated with JESD204C physical or link layers (excluding write-to-clear registers) | The value returned can be affected by radiation (SYSREF_POS, LINK_UP, JSYNC_STATE, PLL_LOCKED, LANE_ARR, FIFO_STATUS, JCAP_STATUS, JCAP, BER_CNT, LANE_EQS, ESDONE, ESVO_S, ECOUNT, RXDMUX, CDRPHASE, RXCSA_S). |
FUSE_DONE register | FUSE_DONE is upset-immune. |
OCSTS register | Once the PHY is initialized and offset calibration is completed, OCSTS returns offset values that are upset immune. However, an upset can cause a PHY PLL to lose lock which can re-trigger the offset calibration process, generating new offset calibration values. |
Sticky SPI status registers (write-to-clear) |
These bits are set when certain events occur in upset-vulnerable logic. An upset can cause the event to occur, and set the sticky bit. An upset can also prevent an event from setting the sticky bit; however this is unlikely as the window of time that this can occur is small. Once the sticky bit is set, an upset does not clear the bit (the flop that is read by SPI is upset immune). Examples: LANE_ERR, PLL_LOCK_LOST, SYS_ALM, REALIGNED, CLK_REALIGNED. |
JESD204C Receiver | The JESD204C receiver is not upset immune, but is designed to be free from functional interrupts (can recover automatically from upsets). See JESD204C Reliability. |
Interpolation Filters (DUC and DES2X filters) | The interpolation filters are not upset immune and can generate glitches when upset. The filters do not suffer from functional interrupts. |
NCOs in DUCs | The radiation sensitivity of the NCO is TBD. |
Temperature Sensor | The ADC inside the temperature sensor is not upset immune. To improve reliability, the recommendation is to read TS_TEMP three or more times, and compute the median value. |