SPRS945G January 2017 – January 2023 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
PRODUCTION DATA
The ADC input characteristics are given by Table 7-16 and Figure 7-43.
DESCRIPTION | REFERENCE MODE | VALUE | |
---|---|---|---|
Cp | Parasitic input capacitance | All | See Table 7-17 |
Ron | Sampling switch resistance | External Reference, 2.5-V Internal Reference | 500 Ω |
3.3-V Internal Reference | 860 Ω | ||
Ch | Sampling capacitor | External Reference, 2.5-V Internal Reference | 12.5 pF |
3.3-V Internal Reference | 7.5 pF | ||
Rs | Nominal source impedance | All | 50 Ω |
This input model should be used with actual signal source impedance to determine the acquisition window duration. For more information, see the Choosing an Acquisition Window Duration section of the Analog-to-Digital Converter (ADC) chapter in the TMS320F28004x Real-Time Microcontrollers Technical Reference Manual. For more information about charge-sharing driving circuits, see the Charge-Sharing Driving Circuits for C2000 ADCs application report. For recommendations on improving ADC input circuits, see the ADC Input Circuit Evaluation for C2000 MCUs application report.
Table 7-17 lists the parasitic capacitance on each channel.
ADC CHANNEL | Cp (pF) | |
---|---|---|
COMPARATOR DISABLED | COMPARATOR ENABLED | |
ADCINA0 | 12.7 | 15.2 |
ADCINA1 | 13.7 | 16.2 |
ADCINA2 | 9.2 | 11.7 |
ADCINA3 | 6.9 | 9.4 |
ADCINA4 | 9.2 | 11.7 |
ADCINA5 | 7.5 | 10 |
ADCINA6 | 8.0 | 10.5 |
ADCINA7 | 7.0 | 9.5 |
ADCINA8 | 10.0 | 12.5 |
ADCINA9 | 8.1 | 10.6 |
ADCINA10 | 9.3 | 11.8 |
ADCINB0 | 7.1 | 9.6 |
ADCINB1 | 9.3 | 11.8 |
ADCINB2 | 9.6 | 12.1 |
ADCINB3(1) | 125.6 | 128.1 |
ADCINB4 | 8.8 | 11.3 |
ADCINB5 | 7.1 | 9.6 |
ADCINB6 | 9.2 | 11.7 |
ADCINB8 | 9.2 | 11.7 |
ADCINB15 | 12.7 | 15.2 |
ADCINC0 | 6.4 | 8.9 |
ADCINC1 | 6.1 | 8.6 |
ADCINC2 | 5.24 | 7.74 |
ADCINC3 | 5.5 | 8 |
ADCINC4 | 6.2 | 8.7 |
ADCINC5 | 5.6 | 8.1 |
ADCINC6 | 9.6 | 12.1 |
ADCINC8 | 8.8 | 11.3 |
ADCINC10 | 9.3 | 11.8 |
ADCINC12 | 4.1 | 6.6 |
ADCINC14 | 4.5 | 7 |
ADCINC15 | 12.7 | 15.2 |