Voltage conversion apparatus suitable for a pixel driver and methods
View Patent ↗Apparatus and methods are disclosed that can provide for voltage translation and conversion that can be applied, as an example, in a microdisplay including a plurality of pixels that are driven at a pixel drive voltage. A pixel is configured to receive a lower pixel drive voltage for one state of the pixel and an upper pixel drive voltage for an opposite state of the pixel. A memory circuit selectively couples the pixel to the lower voltage and the upper pixel drive voltage in response to control signals operable between the lower voltage and an intermediate voltage level that is less than the upper pixel drive voltage.
1. A microdisplay system, comprising:
a microdisplay including a pixel configured to receive a lower pixel drive voltage for one state of the pixel and an upper pixel drive voltage for an opposite state of the pixel; and
an eight transistor pixel driver circuit including first and second cross-coupled inverters forming a four transistor latch, the first inverter including a first inverter output and the second inverter including a second inverter output;
a BLCLR transistor in electrical communication with a word line and a BLCLR line to selectively output each of the lower pixel drive voltage and an intermediate voltage that is between the lower pixel drive voltage and the upper pixel drive voltage;
a BLSET transistor in electrical communication with the word line and a BLSET line to selectively output each of the lower pixel drive voltage and the intermediate voltage;
a first isolation transistor coupled between the BLCLR transistor and the first inverter to drive the first inverter at the lower pixel drive voltage to selectively produce the upper pixel drive voltage at the first inverter output of the first inverter in a first state of the four transistor latch and to electrically isolate the BLCLR transistor from the upper pixel drive voltage in the first state of the four transistor latch;
a second isolation transistor coupled between the BLSET transistor and the second inverter to drive the second inverter at the lower pixel drive voltage to selectively produce the upper pixel drive voltage at the second inverter output in a second state of the four transistor latch and to electrically isolate the BLSET transistor from the upper pixel drive voltage in the second state of the four transistor latch; and
a selected one of the first and second inverter outputs electrically connected to the pixel.