US Patent 7193447 Differential sense amplifier latch for high common mode input

A sense amplifier latch that is operable to interface with high common-mode input voltages with wide ranges for all process variations. The sense amplifier latch comprises a cross-coupled latch having first and second rail signals; a pre-charge device; an equalization device; pass devices for enabling input devices to receive pad and reference inputs. In the present invention, the input devices comprise push-pull impedance dividers are used to preserve the input difference voltage while dramatically lowering the common-mode output voltage. The outputs of the impedance dividers are fed to the cross-coupled latch of the sense amplifier using n-channel pass gates.