The following are some common 8-pin voltage controlled oscillator chips:

1. XR2206: a voltage controlled oscillator chip that integrates sine wave, square wave and triangle wave output. Suitable for applications such as audio and signal generators.

2. CD4046: A phase-locked loop (PLL) chip that can be used in applications such as frequency synthesis and clock recovery.

3. MAX038: A high-precision, low-distortion voltage-controlled oscillator chip that can produce high-quality sine waves, square waves, and triangle waves.

4. LM566: A wide frequency range voltage controlled oscillator chip suitable for frequency synthesis and signal generator applications.

5. ICL8038: A multifunctional voltage-controlled oscillator chip that can generate sine waves, square waves and triangle waves, and has frequency and amplitude adjustment functions.

These are just some common 8-pin voltage controlled oscillator chips. There are also chips of different models and specifications produced by other manufacturers on the market to choose from. When selecting a chip, it needs to be evaluated and selected based on specific application needs and performance requirements.