Calculadora de Seguidor de Tensão
Analise o circuito seguidor de tensão (buffer) com ganho unitário para isolamento de impedância.
V
kΩ
Ω
Tensão de Saída
3.300 V
Corrente de Carga33.00 mA
Without Buffer (loaded)0.003 V
Output Voltage vs Input Voltage
Formula
## Voltage Follower (Buffer) ### Principle **V_out = V_in** (gain = 1) The buffer presents very high input impedance (megohms) and low output impedance (ohms). It prevents a low-impedance load from dragging down a high-impedance source.
Exemplo Resolvido
3.3 V from a 100k source driving a 100 ohm load.
- 01With buffer: V_out = 3.3 V (no loading)
- 02Load current = 3.3 / 100 = 33 mA
- 03Without buffer: V = 3.3 x 100 / (100000 + 100) = 0.0033 V (severe loading)
Perguntas Frequentes
Why use a buffer if gain is 1?
It isolates the source from the load. The op-amp supplies load current so the source does not have to.
What limits the output current?
The op-amp output current capability, typically 10-40 mA for standard parts.
Is it stable?
Voltage followers have 100% feedback so they need a unity-gain-stable op-amp. Not all op-amps are stable at gain = 1.
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