| 摘要 |
A circuit protects differential inputs of circuitry, such as RF circuitry, against electrostatic discharge. The circuit includes first and second diodes (Q1, D2) connected in opposite directions between a first differential input pin (IP) and a virtual ground node (236), third and fourth diodes (Q3, D4) connected in opposite directions between a second differential input pin (IPB) and the virtual ground node (236), a first protection device (D5) connected between the virtual ground node (236) and a first external pin, such as a positive supply pin (VCC) and a second protection device (D6) connected between the virtual ground node (236) and a second external pin, such as a negative supply pin (VEE). The first and second protection devices may be fifth and sixth diodes, respectively. Because no signal appears at the virtual ground node, the capacity of the fifth and sixth diode has virtually no influence, and therefore, the fifth and sixth diodes can be relatively large. |
