JAJSIR1B March 2020 – December 2020 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
PRODUCTION DATA
The ADC input characteristics are given by Table 7-10 and Figure 7-34.
DESCRIPTION | REFERENCE MODE | VALUE | |
---|---|---|---|
Cp | Parasitic input capacitance | All | See Table 7-11 |
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 TMS320F28002x Real-Time Microcontrollers Technical Reference Manual.
Table 7-11 lists the parasitic capacitance on each channel.
ADC CHANNEL | Cp (pF) | |
---|---|---|
COMPARATOR DISABLED | COMPARATOR ENABLED | |
ADCINA0/ADCINC15 | 3.3 | 15.8 |
ADCINA1 | 2.4 | 4.9 |
ADCINA2/ADCINC9 | 2.9 | 5.4 |
ADCINA3/ADCINC5(1) | 71.4 | 73.9 |
ADCINA4/ADCINC14 | 4.5 | 7 |
ADCINA5/ADCINC2 | 2.7 | 5.2 |
ADCINA6 | 2.6 | 5.1 |
ADCINA7/ADCINC3 | 4.2 | 6.7 |
ADCINA8/ADCINC11 | 4.5 | 7 |
ADCINA9/ADCINC8 | 3.4 | 5.9 |
ADCINA10/ADCINC10 | 2.9 | 5.4 |
ADCINA11/ADCINC0 | 2.9 | 5.4 |
ADCINA12/ADCINC1 | 4.7 | 7.2 |
ADCINA14/ADCINC4 | 2.5 | 5 |
ADCINA15/ADCINC7 | 3.3 | 5.8 |
ADCINC6 | 2.9 | 5.4 |