STM32L151VD datasheet(29/154 Pages) STMICROELECTRONICS

29 / 154 page

DocID022027 Rev 11

29/154

STM32L151xD STM32L152xD

Functional overview

The operational amplifiers feature:

•

Low input bias current

•

Low offset voltage

•

Low-power mode

•

Rail-to-rail input

3.14

Ultra-low-power comparators and reference voltage

The STM32L151xD and STM32L152xD devices embed two comparators sharing the same

current bias and reference voltage. The reference voltage can be internal or external

(coming from an I/O).

•

One comparator with fixed threshold

•

One comparator with rail-to-rail inputs, fast or slow mode. The threshold can be one of

the following:

–

DAC output

–

External I/O

–

Internal reference voltage (VREFINT) or a sub-multiple (1/4, 1/2, 3/4)

Both comparators can wake up from Stop mode, and be combined into a window

comparator.

The internal reference voltage is available externally via a low-power / low-current output

buffer (driving current capability of 1 µA typical).

3.15

System configuration controller and routing interface

The system configuration controller provides the capability to remap some alternate

functions on different I/O ports.

The highly flexible routing interface allows the application firmware to control the routing of

different I/Os to the TIM2, TIM3 and TIM4 timer input captures. It also controls the routing of

internal analog signals to ADC1, COMP1 and COMP2 and the internal reference voltage

VREFINT.

3.16

Touch sensing

The STM32L151xD and STM32L152xD devices provide a simple solution for adding

capacitive sensing functionality to any application. These devices offer up to 34 capacitive

sensing channels distributed over 11 analog I/O groups. Both software and timer capacitive

sensing acquisition modes are supported.

Capacitive sensing technology is able to detect the presence of a finger near a sensor which

is protected from direct touch by a dielectric (glass, plastic...). The capacitive variation

introduced by the finger (or any conductive object) is measured using a proven

implementation based on a surface charge transfer acquisition principle. It consists of

charging the sensor capacitance and then transferring a part of the accumulated charges

into a sampling capacitor until the voltage across this capacitor has reached a specific

threshold. The capacitive sensing acquisition only requires few external components to

STM32L151VD Datasheet(PDF) 29 Page - STMicroelectronics

STM32L151VD Datasheet(HTML) 29 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL