SPRADO8A March 2025 – May 2026 AM62L
Figure 6-6 includes crystal + load cap + series resistor + parallel resistor for LFOSC0 (32.768KHz) clock source. Provision to ground Xi using 0R is provided to configure the LFOSC0 when not used as per processor-specific data sheet.
A low frequency (32.768kHz) LFOSC0 is supported by the processor family. Based on the use case, a 32.768kHz external crystal + internal oscillator can be used as the clock source or an external 1.8V LVCMOS square-wave digital clock source can be used.
LFOSC0 has specific use cases (RTC only mode or RTC + IO + DDR low-power mode) and can be optional based on the custom design implementation. When LFOSC0 is not used, the recommendation is to connect the LFOSC0_XI to VSS and leave the LFOSC0_XO unconnected. For more information on connecting the unused LFOSC0, see the LFOSC0 Not Used section of the processor-specific data sheet.
For more information, see the following FAQs:
[FAQ] AM62L (AM62L32, AM62L31): Custom Board Hardware design - LFOSC usage in the processor
The recommendation is to place the discrete components used to implement the external crystal based oscillator close to the LFOSC0_XI and LFOSC0_XO pins. For the crystal, the load capacitance selected is recommended to be in the range specified in the LFOSC0 Crystal Electrical Characteristics table of the processor-specific data sheet. There is no requirement to add the PCB capacitance to the load capacitance.
The figure LFOSC0 Crystal Implementation in the processor-specific data sheet shows the recommended crystal circuit. TI recommends that preproduction printed-circuit board (PCB) designs include the two optional resistors Rbias and Rd in case these are required for proper oscillator operation when combined with production crystal circuit components. In a number of use cases, DNI or delete Rbias and Rd is a 0Ω resistor. The resistors option can be removed from production PCB designs after evaluating oscillator performance with production crystal circuit components installed on preproduction PCB.