摘要 |
An improved reference voltage (Vref) generator for a single-ended receiver in a communication system is disclosed. The Vref generator in one example comprises a cascoded current source for providing a current, I, to a resistor, Rb, to produce the Vref voltage (I*Rb). Because the current source isolates Vref from a first of two power supplies, Vref will vary only with the second power supply coupled to Rb. As such, the improved Vref generator is useful in systems employing signaling referenced to that second supply but having decoupled first supplies. For example, in a communication system in which the second supply (E.g. Vssq) is common to both devices, but the first supply (Vddq) is not, the disclosed Vref generator produces a value for Vref that tracks Vssq but not the first supply. This improves the sensing of Vssq-referenced signals in such a system. |