SLAAE76C March 2023 – May 2025 MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G3105 , MSPM0G3106 , MSPM0G3107 , MSPM0G3505 , MSPM0G3506 , MSPM0G3507
MSPM0G devices have a 12-bit, up to 4Msps, analog-to-digital converter (ADC). The ADC supports fast 12-, 10-, and 8-bit analog-to-digital conversions. The ADC implements a 12-bit SAR core, sample or conversion mode control, and up to 12 independent conversion-and-control buffers.
Figure 6-1 ADC Input NetworkTo achieve the desired conversion speed and keep high accuracy, make sure there is proper sampling time in hardware designs. Sampling (sample-and-hold) time determines how long to sample a signal before digital conversion. During sample time, an internal switch allows the input capacitor to be charged. The required time to fully charge the capacitor is dependent on the external analog front-end (AFE) connected to the ADC input pin. Figure 6-1shows a typical ADC model of an MSPM0G MCU. The Rin and CS/H values can be obtained from the device-specific data sheet. Understand the AFE drive capability and calculate the minimum sampling time required to sample the signal. The resistance of RPar and Rin affects tsample. Equation 1 can be used to calculate a conservative value of the minimum sample time tsample for an n-bit conversion:
To evaluate continuous high speed (4Msps) ADC performance, TI recommends adding an external buffer to make sure of sufficient signal source drive capability. As a design reference, see the LP-MSPM0G3507 hardware design, which includes a recommended external OPA.