MAXQ3100-EMN+ MAXIM [Maxim Integrated Products], MAXQ3100-EMN+ Datasheet - Page 25

• Manufacturer Part Number: MAXQ3100-EMN+
• Description: Mixed-Signal Microcontroller with Analog Comparators, LCD, and RTC
• Manufacturer: MAXIM [Maxim Integrated Products]

The MAXQ3100 incorporates a pair of 1-bit analog-to-
digital comparators. The comparator inputs can be
connected to a wide range of peripherals, including
chemical, motion, or proximity detectors; voltage-sup-
ply monitoring; or any other appropriate analog input.
The comparator measures the analog inputs against
the internal +1.25V reference. The polarity of the inter-
nal comparator-output signal can be selected to indi-
cate a value above or below the internal reference. The
comparators can be configured to generate an optional
interrupt in addition to setting an internal flag when the
input is out of range. A combination of the two com-
parators along with appropriate biasing of an input
allows the two comparators to be used as a window
comparator. When not in use, the pins associated with
the comparator are usable as general-purpose I/O. A
useful feature of the comparators is that they can be
used to wake the device from stop mode, allowing the
device to monitor external voltages while in an ultra-
low-power mode and only wake when necessary.
The internal temperature sensor has a user-selectable
resolution of 10 (0.5°C), 11 (0.25°C), 12 (0.125°C), or
13 (0.0625°C) bits. Higher resolutions require longer
conversion times.
Setting the START bit initiates the temperature conver-
sion, and the temperature sensor hardware clears the
bit when the conversion is complete. This bit can be
Figure 5. Analog Comparator Functional Diagram
CMON
CMPx
Mixed-Signal Microcontroller with Analog
REFERENCE
______________________________________________________________________________________
INTERNAL
1.25V
Analog Comparators
Temperature Sensor
CMPOL
Comparators, LCD, and RTC
CMM
polled by software, or, optionally, the temperature con-
version complete interrupt can be used to alert the sys-
tem that the results are ready to be read from the
temperature results register (TEMPR).
Careful PC-board layout significantly minimizes
crosstalk among the comparator inputs and other digital
signals. Keep digital and analog lines separate, and use
ground traces as shields between them where possible.
Bypass DV
bypass capacitor leads short for best noise rejection.
This device incorporates both analog and digital com-
ponents, straddling both the analog and digital ground
planes. For increased accuracy, an LC filter can be
used to isolate pin 59. This pin powers the analog cir-
cuitry, and the additional filtering reduces the noise
entering the analog block.
The low-power, high-performance RISC architecture of
the MAXQ3100 makes it an excellent fit for many appli-
cations that require analog measurements combined
with the intelligence of a full-featured microcontroller.
Simple voltage-dividers can be used to scale any input
into a value in the range of the +1.25V reference. The
dual comparators allow the device to function as a sim-
ple limit comparator or window comparator in a wide
range of analog applications.
DD
with a capacitor as low as 1µF and keep
Applications Information
SET
Q
Grounds and Bypassing
Device Applications
CMM
INTERRUPT
REQUEST
CMO
CMF
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