Oscillator Options - Microchip Developer Explorer 16/32 User Manual

Explorer 16/32 Development Board User's Guide - Developer Help
SCL pull up resistor and MCP2221A from the P57_SCL net.
J43 – When populated with a 2-pin jumper header, a trace on the bottom of the PCB
can be cut to measure the "9V" rail current consumption of the board, by inserting
an external current meter between the jumper J43 pins.
J44 – When populated with a 2-pin jumper header, a trace on the bottom of the PCB
can be cut to measure the "+5V" rail current consumption of the board, by inserting
an external current meter between the jumper J44 pins.
J45 – When populated with a 2-pin jumper header, a trace on the bottom of the PCB
can be cut to measure the "+3.3V" rail current consumption of the board, by
inserting an external current meter between the jumper J45 pins. Note: To measure
the PIM microcontroller VDD supply current, J50 should be used instead, as the
+3.3 V rail is used to supply additional circuitry on the Explorer 16/32 board, such as
the LCD module, MCP2221A, PKOB circuit, etc., in addition to the PIM
microcontroller.
J50 – This jumper connects the VDD_PIM net to the +3.3 V power supply on the
Explorer 16/32 Development Board. When uncapped, a floating/non-earth ground
referenced current meter (ex: a typical battery operated Digital Multi-Meter) may be
connected between the pins to measure the current consumed by the PIM, on the
VDD_PIM net. When not being used for current measurements, the jumper should
be maintained consistently capped, to ensure the PIM microcontroller gets power.
Note: When using a DMM to measure the current, it is important to be aware of the
local voltage drop that may occur across the DMM's internal sense resistance,
especially when drawing several mA or tens of mA, when operating on the more
sensitive DMM current measurement scales (ex: 0.1 µA or 1.0 µA/least significant
digit count). Under these conditions, the resistive drop across the DMM's internal
sense resistance can often be quite high, possibly hundreds of millivolts or more,
potentially resulting in unexpected behavior (ex: BOR reset of the PIM
microcontroller, if operating near the BOR threshold). To minimize this voltage drop,
it is generally recommended to use a coarser/higher current measurement scale,
whenever possible.

Oscillator Options

The Explorer 16/32 Development Board comes with two crystals, 8 MHz (Y3) and
32.768 kHz (Y2) for use with PIM microcontroller primary and secondary oscillator
circuits respectively. Although not populated by default, the board also has
provisions for the installation of a canned oscillator or socket, allowing the Plug-In
Modules (PIM) microcontroller to be operated in EC or ECPLL modes, at a custom
frequency.
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http://microchipdeveloper.com/boards:explorer1632
7.6.2017 8:59