EFM32LG380 Datasheet, PDF (6/82 Pages) Silicon Laboratories – Output state retention and wake-up from Shutoff Mode

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2.1.19 Real Time Counter (RTC)
The Real Time Counter (RTC) contains a 24-bit counter and is clocked either by a 32.768 kHz crystal
oscillator, or a 32.768 kHz RC oscillator. In addition to energy modes EM0 and EM1, the RTC is also
available in EM2. This makes it ideal for keeping track of time since the RTC is enabled in EM2 where
most of the device is powered down.
2.1.20 Backup Real Time Counter (BURTC)
The Backup Real Time Counter (BURTC) contains a 32-bit counter and is clocked either by a 32.768 kHz
crystal oscillator, a 32.768 kHz RC oscillator or a 1 kHz ULFRCO. The BURTC is available in all Energy
Modes and it can also run in backup mode, making it operational even if the main power should drain out.
2.1.21 Low Energy Timer (LETIMER)
The unique LETIMER^TM, the Low Energy Timer, is a 16-bit timer that is available in energy mode EM2
in addition to EM1 and EM0. Because of this, it can be used for timing and output generation when most
of the device is powered down, allowing simple tasks to be performed while the power consumption of
the system is kept at an absolute minimum. The LETIMER can be used to output a variety of waveforms
with minimal software intervention. It is also connected to the Real Time Counter (RTC), and can be
configured to start counting on compare matches from the RTC.
2.1.22 Pulse Counter (PCNT)
The Pulse Counter (PCNT) can be used for counting pulses on a single input or to decode quadrature
encoded inputs. It runs off either the internal LFACLK or the PCNTn_S0IN pin as external clock source.
The module may operate in energy mode EM0 – EM3.
2.1.23 Analog Comparator (ACMP)
The Analog Comparator is used to compare the voltage of two analog inputs, with a digital output indi-
cating which input voltage is higher. Inputs can either be one of the selectable internal references or from
external pins. Response time and thereby also the current consumption can be configured by altering
the current supply to the comparator.
2.1.24 Voltage Comparator (VCMP)
The Voltage Supply Comparator is used to monitor the supply voltage from software. An interrupt can
be generated when the supply falls below or rises above a programmable threshold. Response time and
thereby also the current consumption can be configured by altering the current supply to the comparator.
2.1.25 Analog to Digital Converter (ADC)
The ADC is a Successive Approximation Register (SAR) architecture, with a resolution of up to 12 bits
at up to one million samples per second. The integrated input mux can select inputs from 8 external
pins and 6 internal signals.
2.1.26 Digital to Analog Converter (DAC)
The Digital to Analog Converter (DAC) can convert a digital value to an analog output voltage. The DAC
is fully differential rail-to-rail, with 12-bit resolution. It has two single ended output buffers which can be
combined into one differential output. The DAC may be used for a number of different applications such
as sensor interfaces or sound output.
2.1.27 Operational Amplifier (OPAMP)
The EFM32LG380 features 3 Operational Amplifiers. The Operational Amplifier is a versatile general
purpose amplifier with rail-to-rail differential input and rail-to-rail single ended output. The input can be set
to pin, DAC or OPAMP, whereas the output can be pin, OPAMP or ADC. The current is programmable
2014-06-13 - EFM32LG380FXX - d0112_Rev1.30
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