SPRZ412N December 2013 – May 2024 TMS320F28374D , TMS320F28375D , TMS320F28376D , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28378D , TMS320F28379D , TMS320F28379D-Q1
INTOSC: VDDOSC Powered Without VDD Can Cause INTOSC Frequency Drift
0, A, B, C
The "K" revision of the TMS320F2837xD Dual-Core Real-Time Microcontrollers data sheet (SPRS880K) has updated power sequencing requirements. Revision "J" and earlier revisions of the data sheet did not require VDDOSC and VDD to be powered on and powered off at the same time.
If VDDOSC is powered on while VDD is not powered, there will be an accumulating and persistent downward frequency drift for INTOSC1 and INTOSC2. The rate of drift accumulated will be greater when VDDOSC is powered without VDD at high temperatures.
As a result of this drift, the INTOSC1 and INTOSC2 internal oscillator frequencies could fall below the minimum values specified in the data sheet. This would impact applications using INTOSC2 as the clock source for the PLL, with the system operating at a lower frequency than expected.