Datasheet

DocID17659 Rev 9 55/131
STM32L151x6/8/B, STM32L152x6/8/B Electrical characteristics
105
6.3.3 Embedded internal reference voltage
The parameters given in the following table are based on characterization results, unless
otherwise specified.
Table 15. Embedded internal reference voltage calibration values
Calibration value name Description Memory address
VREFINT_CAL
Raw data acquired at
temperature of 30 °C, V
DDA
= 3 V
0x1FF8 0078-0x1FF8 0079
Table 16. Embedded internal reference voltage
Symbol Parameter Conditions Min Typ Max Unit
V
REFINT out
(1)
Internal reference voltage – 40 °C < T
J
< +105 °C 1.202 1.224 1.242 V
I
REFINT
Internal reference current consumption - - 1.4 2.3 µA
T
VREFINT
Internal reference startup time - - 2 3 ms
V
VREF_MEAS
V
DDA
and V
REF+
voltage during
V
REFINT
factory measure
- 2.99 3 3.01 V
A
VREF_MEAS
Accuracy of factory-measured V
REF
value
(2)
Including uncertainties
due to ADC and
V
DDA
/V
REF+
values
--±5 mV
T
Coeff
(3)
Temperature coefficient
–40 °C < T
J
< +105 °C - 20 50
ppm/°C
0 °C < T
J
< +50 °C - - 20
A
Coeff
(3)
Long-term stability 1000 hours, T= 25 °C - - 1000 ppm
V
DDCoeff
(3)
Voltage coefficient 3.0 V < V
DDA
< 3.6 V - - 2000 ppm/V
T
S_vrefint
(3)(4)
ADC sampling time when reading the
internal reference voltage
-510-µs
T
ADC_BUF
(3)
Startup time of reference voltage buffer
for ADC
---10µs
I
BUF_ADC
(3)
Consumption of reference voltage
buffer for ADC
- - 13.5 25 µA
I
VREF_OUT
(3)
VREF_OUT output current
(5)
---1µA
C
VREF_OUT
(3)
VREF_OUT output load - - - 50 pF
I
LPBUF
(3)
Consumption of reference voltage
buffer for VREF_OUT and COMP
- - 730 1200 nA
V
REFINT_DIV1
(3)
1/4 reference voltage - 24 25 26
% V
REFINT
V
REFINT_DIV2
(3)
1/2 reference voltage - 49 50 51
V
REFINT_DIV3
(3)
3/4 reference voltage - 74 75 76
1. Tested in production.
2. The internal V
REF
value is individually measured in production and stored in dedicated EEPROM bytes.
3. Guaranteed by design, not tested in production.
4. Shortest sampling time can be determined in the application by multiple iterations.
5. To guarantee less than 1% VREF_OUT deviation.