58.8.2 External Reference Voltage
VVREFP is an external reference voltage applied on the pin VREFP. The quality of the reference voltage VVREFP is critical to the performance of the AFE. A DC variation of the reference voltage VVREFP is converted to a gain error by the AFE. The noise generated by VVREFP is converted by the AFE to count noise.
| Symbol | Parameter | Conditions | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|---|
| VVREFP | Voltage Range | Full operational | 1.7 | – | VDDIN | V |
| RMS Noise (see Note 2) | Bandwidth up to 1.74MHz VREFP=1.7V | – | – | 120 | µV | |
| RVREFP | Input DC Impedance | AFE reference resistance bridge (see Note 1) | – | 4.7 | – | kOhm |
| Vin | Input Linear Range (see Note 3) | Operational Range | 2 | - | 98 | %VVREFP |
| IVREFP | Current | VVREFP = 3.3V | – | 0.8 | – | mA |
Note:
- When the AFE is in Sleep mode, the VREFP impedance has a minimum of 10 MOhm.
- Requested noise on VREFP.
- Electrical parameters specified inside the operational range. Exceeding this range can introduce additional INL error up to +/- 5 LSB and temperature dependency up to +/-10 LSB.