Interpolator and interpolation cells with non-uniform driving capabilities therein

摘要

An interpolator includes interpolation cells. Each interpolation cell includes a first driving unit and a second driving unit. The first driving unit includes a first pulling-up circuit for selectively coupling an output terminal to a high voltage, a first pulling-down circuit for selectively coupling the output terminal to a low voltage, and a pair of first switches for selectively enabling/disabling the first pulling-up circuit and the first pulling-down circuit. The second driving unit includes a second pulling-up circuit for selectively coupling the output terminal to the high voltage, a second pulling-down circuit for selectively coupling the output terminal to the low voltage, and a pair of second switches for selectively enabling/disabling the second pulling-up circuit and the second pulling-down circuit. Driving capabilities of the first and second pulling-up circuits are not all equal, and/or driving capabilities of the first and second pulling-down circuits are not all equal.

主权项

1. An interpolator, comprising:
a plurality of interpolation cells, each comprising: a first driving unit, comprising: a first pulling-up circuit, for selectively coupling an output terminal directly to a high voltage according to a first input signal, wherein the output terminal is used to output an interpolation signal; a first pulling-down circuit, for selectively coupling the output terminal directly to a low voltage according to the first input signal; and a pair of first switches, for selectively enabling the first pulling-up circuit and the first pulling-down circuit according to a control signal; and a second driving unit, comprising: a second pulling-up circuit, for selectively coupling the output terminal directly to the high voltage according to a second input signal; a second pulling-down circuit, for selectively coupling the output terminal directly to the low voltage according to the second input signal; and a pair of second switches, for selectively enabling the second pulling-up circuit and the second pulling-down circuit according to the control signal, wherein in all of the interpolation cells, driving capabilities of the first pulling-up circuits and the second pulling-up circuits are not all equal, and driving capabilities of the first pulling-down circuits and the second pulling-down circuits are not all equal; wherein in each of the interpolator cells, the first pulling-up circuit comprises a first impedance device, and the second pulling-up circuit comprises a second impedance device; and wherein in all of the interpolation cells, the first impedance devices and the second impedance devices are implemented with a plurality of resistors having non-uniform resistances, wherein each of the plurality of resistors is coupled directly to one of: the high voltage and the low voltage, and wherein the plurality of interpolation cells is arranged in the interpolator according to respective driving capabilities such that an interpolation cell having a highest driving capability is coupled closest to the output terminal.