How to Use CVMC10: Examples, Pinouts, and Specs

The CVMC10 is a compact voltage-controlled oscillator (VCO) manufactured by Circurator with the part ID C10. It is designed for generating high-frequency signals with low phase noise, making it an essential component in communication systems, signal processing, and frequency synthesis applications. The CVMC10 offers excellent frequency stability and a wide tuning range, making it suitable for both professional and hobbyist projects.

• Wireless communication systems (e.g., RF transmitters and receivers)
• Signal generators and frequency synthesizers
• Phase-locked loops (PLLs)
• Radar and satellite communication systems
• Test and measurement equipment

The CVMC10 is housed in an 8-pin SOIC package. The pinout and descriptions are as follows:

1. Power Supply: Connect the Vcc pin to a stable DC power supply (3.3V to 5.0V) and the GND pins to the ground of the circuit.
2. Tuning Voltage: Apply a tuning voltage (0.5V to 4.5V) to the TUNE pin to control the output frequency. The frequency increases with the tuning voltage.
3. Output Signal: The RF output signal is available at the OUT pin. Use a 50 Ω load for optimal performance.
4. Enable/Disable: Use the ENABLE pin to control the oscillator. Apply a logic high signal to enable the VCO and a logic low signal to disable it.
5. Bypass Capacitors: Place decoupling capacitors (e.g., 0.1 µF and 10 µF) close to the Vcc pin to reduce noise and ensure stable operation.

• Ensure the tuning voltage does not exceed the specified range (0.5V to 4.5V) to avoid damaging the component.
• Use a low-noise power supply to minimize phase noise in the output signal.
• Keep the RF output trace as short as possible and use proper impedance matching techniques to maintain signal integrity.
• Avoid placing the CVMC10 near high-power or noisy components to prevent interference.

The CVMC10 can be controlled using an Arduino UNO to generate a variable frequency output. Below is an example code to control the tuning voltage using a PWM signal.

// Example: Controlling CVMC10 tuning voltage with Arduino UNO
// This code generates a PWM signal to control the tuning voltage of the CVMC10.
// Ensure a low-pass filter is used to convert the PWM signal to a stable DC voltage.

const int pwmPin = 9; // PWM output pin connected to the TUNE pin of CVMC10

void setup() {
  pinMode(pwmPin, OUTPUT); // Set the PWM pin as an output
}

void loop() {
  for (int dutyCycle = 0; dutyCycle <= 255; dutyCycle++) {
    // Gradually increase the PWM duty cycle from 0 to 255
    analogWrite(pwmPin, dutyCycle);
    delay(20); // Wait for 20ms before increasing the duty cycle
  }

  for (int dutyCycle = 255; dutyCycle >= 0; dutyCycle--) {
    // Gradually decrease the PWM duty cycle from 255 to 0
    analogWrite(pwmPin, dutyCycle);
    delay(20); // Wait for 20ms before decreasing the duty cycle
  }
}

Note: Use a low-pass RC filter (e.g., 10 kΩ resistor and 0.1 µF capacitor) to smooth the PWM signal into a stable DC voltage before connecting it to the TUNE pin.

1. No Output Signal:

   • Ensure the ENABLE pin is set to logic high.
   • Verify the power supply voltage is within the specified range (3.3V to 5.0V).
   • Check the tuning voltage and ensure it is within the 0.5V to 4.5V range.

2. High Phase Noise:

   • Use a low-noise power supply and proper decoupling capacitors.
   • Minimize interference from nearby components by proper PCB layout design.

3. Output Frequency is Incorrect:

   • Verify the tuning voltage applied to the TUNE pin.
   • Check for any impedance mismatches in the output signal path.

4. Component Overheating:

   • Ensure the supply voltage does not exceed 5.0V.
   • Check for short circuits or excessive current draw in the circuit.

Q1: Can the CVMC10 operate at frequencies below 100 MHz?
A1: No, the CVMC10 is designed to operate within the specified frequency range of 100 MHz to 1 GHz.

Q2: What happens if the tuning voltage exceeds 4.5V?
A2: Applying a tuning voltage beyond the specified range may damage the component or result in unpredictable behavior.

Q3: Can I use the CVMC10 with a 3.3V power supply?
A3: Yes, the CVMC10 supports a supply voltage range of 3.3V to 5.0V. Ensure the tuning voltage is scaled accordingly.

Q4: Is the CVMC10 suitable for battery-powered applications?
A4: Yes, its low power consumption and wide operating voltage range make it suitable for battery-powered designs.