Comparing Voltage References - Shunt vs Series
Integrated circuits have revolutionized electronics manufacturing, bringing forth smaller and more powerful devices. A significant part of these circuits is the voltage reference, which plays a crucial role in ensuring the circuitry functions as intended. The two most common types of voltage references are shunt and series, which are often compared. In this blog post, we will compare these voltage references and explore their differences.
Shunt Voltage References
Shunt voltage references are the most common type of voltage reference used in integrated circuits. In shunt references, a reference voltage is generated by continuously passing a current through a diode in reverse bias. The resulting voltage drop across the diode remains relatively constant over a wide range of current values. This voltage then becomes the reference voltage for the circuit.
Shunt voltage references have some distinct advantages. They offer low output voltage noise and good temperature stability, making them suitable for precision applications such as measurement systems or A/D converters. Shunt references are also relatively inexpensive and have low power consumption.
Series Voltage References
Series voltage references are the second most common type of voltage reference used in integrated circuits. In series references, a stable reference voltage is generated by connecting a zener diode in series with a resistor. The voltage across the zener diode remains relatively constant over a wide range of current values, providing a stable reference voltage.
Series voltage references offer several advantages. They are easy to use and can be designed to provide high-precision voltage outputs. They are also immune to load variations, making them suitable for applications such as voltage regulators.
Comparison
The key difference between shunt and series voltage references is their power consumption. Shunt references tend to be more power-efficient compared to series references. Additionally, shunt references offer low output voltage noise and good temperature stability, while series references have better line regulation.
A comparative analysis of performance characteristics of shunt and series voltage references is provided in Table 1.
| Characteristic | Shunt Reference | Series Reference |
|---|---|---|
| Output voltage noise | Low | High |
| Load regulation | Poor | Good |
| Temperature stability | Good | Poor |
| Line regulation | Good | Poor |
| Power consumption | Low | High |
Table 1: Comparison of Shunt and Series References
Conclusion
In conclusion, shunt and series voltage references are critical components in integrated circuits. They provide a stable voltage reference and are essential in ensuring the circuitry functions as intended. Shunt references are suitable for low noise and precision applications, while series references are suitable for high precision and load immunity applications. Ultimately, it is up to the designer to determine which type of voltage reference is best suited for their needs.
References
- Texas Instruments, "Voltage References: Application Notes". https://www.ti.com/lit/an/sloa080/sloa080.pdf, accessed 10 May 2022.
- Analog Devices, "AN-290: Voltage References and Voltage Regulators". https://www.analog.com/media/en/technical-documentation/application-notes/AN290.pdf, accessed 10 May 2022.