The MTi 1-series module has two supply pins: VDDA and VDDIO. They can be supplied independently or tied together to adapt various concepts, depending on the intended application. The different supply voltages are explained in the following subsections.
The VDDIO pin is the main supply of the MTi 1-series module. This pin is connected to all the digital IO’s, and powers the processor on the MTi 1-series module. #Power supply specifications shows the acceptable range of VDDIO. For the most power efficient implementation, the VDDIO pin should be connected to a 2.8 V power supply.
The VDDA pin of the MTi 1-series module is connected to all the power supply pins of the sensing elements that are on the MTi 1-series module. There is no low-dropout regulator (LDO) on the MTi 1‑series. The table below shows the acceptable range of VDDA. To get the best sensor performance, it is important that the VDDA pin is supplied by a power supply with a maximum ripple of 50 mVpp.
The MTi 1-series VDDA and VDDIO supply pins can be connected to the same power supply. When the MTi 1-series is supplied with a single power supply source, it is strongly recommended to decouple the VDDA and VDDIO supply pins with a ferrite bead, for the best sensor performance. See schematic below. This way, the digital circuitry will not affect the analogue sensing part. Due to the varying current required for the VDDA, the DC resistance of the ferrite bead should not be too high. A DC resistance of maximum 1 Ω is recommended.
External components single supply (I2C interface)
The table below shows the maximum operating voltage ratings of the MTi 1-series. Exposure to any voltage beyond maximum operating voltage rating condition for extended periods may affect device reliability and lifetime.
|
|
Min |
Typ |
Max |
Unit |
|---|---|---|---|---|
|
VDDA |
2.8 (HW version ≤3.x: 2.16) |
3.3 |
3.6[1] (HW version ≤1.x: 3.45) |
V |
|
VDDA ripple |
|
50 |
mVpp |
|
|
VDDIO |
2.8 (HW version ≤3.x: 1.8) |
3.3 |
VDDA + 0.1 |
V |
[1] Previous generation version ≤1.1, VDDA max: 3.45V