We used to see dual supply ideal operational amplifiers (Op Amps), what means that Op Amps are powered from dual supplies with equal magnitude and opposing polarity. The center tap is connected to the ground which serves as a center of the supply voltage.

Single supply operational amplifiers are powered with single polarity voltage. In this case you loose convenient ground reference that split supply op amps have. In this case you must ensure that signal swings between correct voltages (eg. VCC and GND). Input sources connected to ground are actually connected to a supply rail in single-supply systems. This is analogous to connecting a dual-supply input to the minus power rail. This requirement for biasing the op amp inputs to achieve the desired output voltage swing complicates single-supply designs.

Simply speaking - use of a single polarity only limits the output voltage range. Lets say f supply voltage is 10V then for single voltage Op Amps maximum output voltage is limited to 10V. if dual voltage is used - same operational amplifier output voltage ranges from -10 to +10V what gives a 20V swing capability. You get not only wider output voltage range, but also a significant flexibility when designing circuits. Actually dial supply circuits are simpler as there is no need for additional reference stings and so on. Dual power op amps need more complex power supplies comparing to single power, but probably this isn’t a problem today as there a wide range of compact voltage regulators that may convert input voltage to any desired.

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This entry was posted on Wednesday, February 6th, 2008 at 2:27 pm and is filed under Electronics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.