Use only a power supply with a voltage rating of 7.5 volts or USB to power this device!
GENERAL GUIDE
The device is an expansion board (shield) for Arduino Mega based on the ATmega2560 microcontroller with 5-volt logic
levels, since the board has logic signal level converters from 5V
to 3.3V.
Power is supplied to the device through the Arduino, and
connection is made either through the power jack (up to 7.5 volts)
or through the USB connector.
To fully operate the device, an I²C OLED display of 0.96
inches is required (optional and not included). The display is
powered by 5 volts from the 5V Pin on the Arduino.
The device is controlled by an encoder and a BACK button
(not used in the current software version). An external encoder
and pushbutton can be connected to the ExENC (PH2.0-3p) and
ExBACK1 (PH2.0-2p) connectors, if needed. The AD9912 clocking
can be done in three ways:
Crystal;
OCXO/TCXO (default);
From an external source, when using it, make sure that capacitor C20 is removed (Figure 2), and resistor PLL_BP 1 kOhm
is installed. To achieve the best results, refer to Table 1.
The type and frequency of the clock source must be correctly set in the device settings. All settings are saved in non-volatile
memory.
The device has 3 outputs types: Sinus, CMOS and Differential HSTL. The output signal of the Sinus channel is taken from
the SMA connector labeled "RF OUT", the output signal of the CMOS channel is taken from the "CMOS" connector, and the output
signals of the HSTL channel are taken from the "HSTL A" and " HSTL B" connectors.
When using an external clock source, the signal is fed to the SMA connector labeled "REF CLK IN", when using it, make sure
that capacitor C20 is removed (Figure 2), and resistor PLL_BP 1 kOhm is installed. To achieve the best results, refer to Table 1.
The device contains an output low-pass filter and a matching output transformer, therefore a software limit of 100 kHz is
applied to the minimum output frequency of the device (Figure 3).
O P E R A T I O N
Rotating the encoder knob moves the cursor through menu items or changes the value of the selected item. Pressing the
encoder knob activates or deactivates the parameter editing mode, or enters a submenu (depending on the context). Fast
rotation of the knob allows jumping through 10 values at a time.
The frequencies at the HSTL and CMOS outputs are tied to the Sinus channel (RF OUT), but the frequency at the HSTL
output can be multiplied by 2, and the frequency at the CMOS output can be divided by a divider ranging from 1 to 65535.
Main menu:
RFsin: sets the frequency at the output of the Sinus channel (RF OUT). The maximum output frequency is limited to 500
MHz, but it is important to note that the maximum output frequency that can be obtained is AD9912 core frequency x 0.4. For
example, with a core frequency of 1 GHz, the maximum output frequency cannot exceed 400 MHz. The core frequency can be
changed in the "Setup" menu. For proper operation of the Sinus channel, the 'CMOS/HSTL ENABLE' jumper must be OPEN. If it
is not removed, the level at the 'RF OUT' output will be reduced by 3dBm!
HSTL: Enables or disables the signal at the HSTL outputs and, and allows doubling the frequency on this channel, in
addition to software configuration, the “CMOS/HSTL ENABLE” jumper must be CLOSED. The voltage on the outputs is switched
by the "REF LEVEL" jumper and can be either 1.8V or 3.3V. The frequency range on this output is 100 kHz to 1 GHz.
CMOS: Enables or disables the signal at the CMOS output, in addition to software configuration, the “CMOS/HSTL ENABLE”
jumper must be CLOSED. The frequency range on this output is 1 Hz to 500 MHz.
