A sensor includes a gain stage with a differential amplifier with an adjustable gain. The differential amplifier may change its gain in response to the magnitude of a signal readout from the pixel array. The differential amplifier includes an input transistor with an adjustable transconductance. A transconductance controller can change the bias currents supplied to one or more sets of parallel transistors in the input transistor and consequently change the transconductance, and power consumption, of the input transistor. The transconductance controller can select a transconductance setting that is associated with a selected gain setting in order to more efficiently match the power consumption of the amplifier to its gain.
A system of reducing power consumption in and active pixels sensor. The sensor is broken into different blocks, and each of the blocks is individually optimized. The optimization may include minimizing the parasitic capacitance on the readout bus, turning off biases when not in use, and operating in a way that minimizes static power consumption of different elements such as A/D converters.
A system of reducing power consumption in and active pixels sensor. The sensor is broken into different blocks, and each of the blocks is individually optimized. The optimization may include minimizing the parasitic capacitance on the readout bus, turning off biases when not in use, and operating in a way that minimizes static power consumption of different elements such as A/D converters.
