74.7.12 Temperature Sensor and Voltage Reference Characteristics
The temperature sensor provides two output voltages that can be converted by the internal
12-bit ADC:
- VTEMP: proportional to the junction temperature (TJ), and
- VBG: temperature-independent voltage.
Both voltages are multiplexed to ADC channel 31. The selection of VTEMP or VBG is done with the ADC_ACR.SRCLCH bit. Calibration data for the temperature sensor are factory-programmed in one OTP controller packet. These calibration data can only be read and used after writing a “Boot Configuration Packet” in the OTP memory. Refer to the application note “SAMA7G5 Series Temperature Sensor Calibration” (AN4530), available on microchip.com.
Symbol | Parameter | Conditions | Min | Max | Unit |
---|---|---|---|---|---|
VDDIN33 | Supply voltage range (VDDIN33)(1) | – | 3.0 | 3.6 | V |
IVDDIN33 | Current consumption(2) | – | – | 200 | µA |
tSTART | Start-up time(3) | – | – | 20 | μs |
VTEMP | Temperature output voltage | TJ = 25°C | 0.59 | 0.67 | V |
dVTEMP/dT | VTEMP sensitivity to temperature(2) | – | 2.08 | mV/°C | |
TACC | Temperature reading accuracy(2)(3) | Over the applicable TJ range | – | ±5 | °C |
VBG0 | VBG reference output voltage | TJ = 27°C | 1.19 | 1.21 | V |
ΔVBG | VBG drift with temperature(2) |
ΔVBG = VBG(TJ)-VBG0 |
-20 | 20 | mV |
tTH |
VTEMP or VBG track-and-hold time(2) |
Required track-and-hold time to ensure 1 LSB accurate settling on internal 12-bit ADC | 1 | – | µs |
Note:
- The temperature sensor is powered by the VDDOUT25 regulator, which is supplied from VDDIN33.
- Simulation data
- Using the temperature sensor calibration procedure described in the application note “SAMA7G5 Series Temperature Sensor Calibration” (AN4530), available on microchip.com.