Which of the following summarizes the important features of emitter-coupled logic (ECL)?

• low noise margin, low output voltage swing, negative voltage operation, fast, and high power consumption
• good noise immunity, negative logic, high-frequency capability, low power dissipation, and short propagation time
• low propagation time, high-frequency response, low power consumption, and high output voltage swings
• poor noise immunity, positive supply voltage operation, good low-frequency operation, and low power