1.2.19 Prescaler Range
The prescaler range is determined from the maximum input voltage field. The following table describes how to calculate your prescaler range.
| Scaling Factor: Pad to ADC Input | LSB for 8-bit conversion (mV) | LSB for 10-bit conversion (mV | LSB for 12-bit conversion (mV | Full-Scale Voltage | Range Name (V) |
|---|---|---|---|---|---|
| 0.15625 | 64 | 16 | 4 | 16.368 | 16 |
| 0.3125 | 32 | 8 | 2 | 8.184 | 8 |
| 0.625 | 16 | 4 | 1 | 4.092 | 4 |
| 1.25 | 8 | 2 | 0.5 | 2.046 | 2 |
| 2.5 | 4 | 1 | 0.25 | 1.023 | 1 |
| 5.0 | 2 | 0.5 | 0.125 | 0.5115 | 0.5 |
| 10.0 | 1 | 0.25 | 0.0625 | 0.25575 | 0.25 |
| 20.0 | 0.5 | 0.125 | 0.03125 | 0.127875 | 0.125 |
If the maximum input voltage is greater than the given range, it will select the higher range. The corresponding ranges for negative polarity is the same.
The prescaler logic of the AB has a settling time of 10s (max). It is an application-dependent setting and must be accounted for by you via the acquisition and hold time for each channel. A recommended default value is inserted by the ASB when configuring a new Voltage Monitor but it may be reduced with a possible reduction in sampling accuracy.