(energetic guitar music)
- Hello, fellow geeks, and welcome to another geek moment.
Today I'd like to introduce you
to the LTC2645 from Linear Technology.
The LTC2645 is a quad
PWM-to-V-out DAC,
available in 8-, 10-, and 12-bit resolutions.
The LTC2645 measures the pulse width and period
of the PWM signal and updates the DAC
on the rising edge of the corresponding PWM.
Each DAC can operate rail-to-rail
using an internal reference
or with 2.5 volt full-scale voltage
using an integrated reference.
The DAC outputs update and settle to a 12-bit accuracy
within 8 microseconds and are capable
of sinking and sourcing 5 milliamps at 3 volts
or 10 milliamps at 5 volts, eliminating voltage ripple
and replacing slow analog filters and buffer amplifiers.
The LTC2645 operates
from a single 2.7 to 5.5 volt supply
and supports PWM inputs from 1.71 volts to 5.5 volts.
In our demonstration today we will be using
the LTC2645 demonstration board
and the Linduino One.
The Linduino development platform
is an Arduino-compatible development board
with a large firmware library.
Linduino One is fully USB isolated
and is meant to provide a stable development platform.
Example firmware can be downloaded and compiled,
giving users a head start developing with Linear Tech parts.
The LTC2645 demo board comes complete and ready to use.
There's no need to solder on headers or change jumpers.
It connects to the Linduino One much like a shield
would connect to an Arduino.
Like that.
To start developing with the LTC2645,
use the USB cable provided with the Linduino
to connect it to a web-enabled computer.
And for this demo, we will be using an O-scope
to show the waveforms.
We will connect one channel to voltage out A
and the other channel we will connect to input A.
And now for some software.
The Linduino code for use with the LTC2645 demo system
can be downloaded at
www.linear.com/docs/43962
Then please run the installer
on a computer with internet access
and follow the prompts to complete installation.
When completed, download the LT sketchbook at
www.linear.com/docs/43958.
Once the software is downloaded and installed,
open the Arduino IDE,
click on file, sketchbook,
part number, 2000, 2600, and click on 2645,
click on DC2197 to open the sketchbook
for the LTC2645 demo board example code.
Upload, and once complete, open the serial monitor.
Simply follow the onscreen instructions
to change the voltage of the output on the DAC,
select which DAC you would like to operate,
then set the duty cycle, enter one to enter a voltage,
enter the desired voltage,
and see that the PWM input has changed.
The LTC2645 demo board, along with the Linduino,
make it easy to evaluate the LTC2645.
Go to digikey.com
and search LTC2645 demo board
to find out more.
Thanks for watching.
(energetic guitar music)