Patent ID: 8723855
Filing Date: 2014-05-13
Classification: G06F

Abstract:
1. A mutual capacitance touchscreen controller, comprising: an analog core comprising touchscreen sense circuitry configured to be operably connected to capacitive touchscreen sense lines external to the controller; a first on-chip low drop out regulator (LDO) configured to receive and regulate as a first input thereto an input supply voltage (VSUPPLY), and to provide as an output therefrom a first regulated output voltage (VDDA); a first comparator configured to receive as first and second inputs thereto VSUPPLY and VDDA and to provide as an output therefrom a signal EN, EN being provided to the first LDO as a second input thereto; wherein the first LDO is configured to operate in a first off mode and is turned off by signal EN when the difference between VSUPPLY and VDDA is less than a predetermined threshold, and the touchscreen controller is configured to operate in an LDO mode wherein VDDA is provided as an output from the first LDO when the difference between VSUPPLY and VDDA is greater than or equal to the predetermined threshold and the first LDO is turned on and operating in a second on mode.