Abstract: Systems, methods, and devices are provided for calibrating and correcting a clock duty cycle. An integrated circuit may include a clock tree that provides a clock signal and a circuit that is sensitive to clock duty cycle that receives the clock signal at a lower level of the clock tree. A first duty cycle correction circuit may adjust a clock duty cycle of the clock signal to a first target duty cycle at a higher level of the clock tree. A second duty cycle correction circuit may adjust a clock duty cycle of the clock signal to a second target duty cycle at the lower level of the clock tree.

Abstract: Systems, methods, and devices are provided for calibrating and correcting a clock duty cycle. An integrated circuit may include a clock tree that provides a clock signal and a circuit that is sensitive to clock duty cycle that receives the clock signal at a lower level of the clock tree. A first duty cycle correction circuit may adjust a clock duty cycle of the clock signal to a first target duty cycle at a higher level of the clock tree. A second duty cycle correction circuit may adjust a clock duty cycle of the clock signal to a second target duty cycle at the lower level of the clock tree.

Abstract: According to one embodiment, a voltage reference circuit operable with a low voltage supply comprises an op-amp powered by the low voltage supply and a feedback branch including a transistor driven by an output of the op-amp. The feedback branch couples the low voltage supply to ground through the transistor and at least a rectifying device situated between a reference node of the feedback branch and ground. An input of the op-amp is coupled to the reference node by a voltage divider. In one embodiment, the voltage reference circuit further comprises a reference branch coupling a second reference node to ground through at least a second rectifying device, and wherein a second input of the op-amp is coupled to the second reference node by a second voltage divider.

Abstract: A precise current cell for a digital-to-analog (D/A) convertor circuit is designed to compensate for manufacturing process variations. The cell uses a cascoded transistor chain to control the output voltage and isolate voltage supply noise. An external (off-chip) bias current is fed into a cascoded biasing string of eight transistors, which are further mirrored to the current cell itself. The biasing scheme accounts for manufacturing process variations in the chip, which leads to very precise current being replicated at the output of the D/A circuit. Current steering and an improved shunt path within the current cell minimizes voltage swings during switching of the current cell. This allows for faster switching of the cell while minimizing noise coupling due to the voltage swings. The current cell also has an associated biasing stage. This biasing stage allows for improved matching within the current cell, resulting in improved accuracy of conversion.