STM32L151XX Datasheet, PDF (93/121 Pages) STMicroelectronics – Ultra-low-power 32-bit MCU ARM-based Cortex-M3, 128KB Flash, 16KB SRAM, 4KB EEPROM, LCD, USB, ADC, DAC

STM32L151x6/8/B, STM32L152x6/8/B
Electrical characteristics
Figure 25. ADC accuracy characteristics
4095
4094
4093
7
6
5
4
3
2
1
[1LSB_IDEAL
=V^REF+
4096
(or
V_{DDA depending}
4096
on
package)]
E_G
(2)
E_T
(3)
(1)
E_O
E_L
E_D
1 LSB_IDEAL
(1) Example of an actual transfer curve
(2) The ideal transfer curve
(3) End point correlation line
E_T=Total Unadjusted Error: maximum deviation
between the actual and the ideal transfer curves.
E_O=Offset Error: deviation between the first actual
transition and the first ideal one.
E_G=Gain Error: deviation between the last ideal
transition and the last actual one.
E_D=Differential Linearity Error: maximum deviation
between actual steps and the ideal one.
E_L=Integral Linearity Error: maximum deviation
between any actual transition and the end point
correlation line.
0
1234567
V_SSA
4093 4094 4095 4096
V_DDA
ai14395b
Figure 26. Typical connection diagram using the ADC
R_AIN(1)
AINx
VAIN
C _parasitic
VDD
VT
0.6 V
VT
0.6 V
IL± 50 nA
STM32L15xxx
Sample and hold ADC
converter
12-bit
converter
C_ADC(1)
ai17856c
1. Refer to Table 56: R_AIN max for f_ADC = 16 MHz for the value of RAIN and Table 54: ADC characteristics for
the value of CADC
2. C_parasitic represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the
pad capacitance (roughly 7 pF). A high C_parasitic value will downgrade conversion accuracy. To remedy
this, f_ADC should be reduced.
Doc ID 17659 Rev 8
93/121