...the world's most energy friendly microcontrollers
2014-07-02 - Tiny Gecko Family - d0034_Rev1.20
391
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Bias Current (µA)
BIAS
HALFBIAS=0
HALFBIAS=1
0b0100
0.8
0.4
0b0101
1.0
0.5
0b0110
1.2
0.6
0b0111
1.4
0.7
0b1000
2.0
1.0
0b1001
2.2
1.1
0b1010
2.4
1.2
0b1011
2.6
1.3
0b1100
2.8
1.4
0b1101
3.0
1.5
0b1110
3.2
1.6
0b1111
3.4
1.7
23.3.3 Hysteresis
In the voltage supply comparator, hysteresis can be enabled by setting HYSTEN in VCMP_CTRL. When
HYSTEN is set, the digital output will not toggle until the positive input voltage is at least 20mV above
or below the negative input voltage. This feature can be used to filter out uninteresting input fluctuations
around zero and only show changes that are big enough to breach the hysteresis threshold.
Figure 23.2. VCMP 20 mV Hysteresis Enabled
In
NEG
VCMPOUT wit h hyst eresis
In
NEG
+ 20m V
In
NEG
- 20m V
VCMPOUT wit hout hyst eresis
Tim e
In
POS
23.3.4 Input Selection
The positive comparator input is always connected to the scaled power supply input. The negative
comparator input is connected to the internal 1.25 V bandgap reference. The V
DD
trigger level can be
configured by setting the TRIGLEVEL field in VCMP_CTRL according to the following formula:
VCMP V
DD
Trigger Level
V
DD Trigger Level
= 1.667V + 0.034V × TRIGLEVEL
(23.1)
A low power reference mode can be enabled by setting the LPREF bit in VCMP_INPUTSEL. In this mode,
the power consumption in the reference buffer (V
DD
and bandgap) is lowered at the cost of accuracy.
Summary of Contents for EFM32TG
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