Differential OTP Memory Array Density and Variation Robustness

The patent employs differential pairing of PMOS transistors where each pair consists of a first PMOS and a second PMOS with complementary configurations. The first PMOS has its source connected to a first bit line and drain to a first word line, while the second PMOS has its source connected to a second bit line and drain to the same first word line. This asymmetric differential structure allows the memory cell to compare threshold voltage differences between paired transistors, thereby compensating for global process variations and improving robustness.

The patent merges latching circuit functionality into the differential PMOS transistor pairs themselves. Each differential pair inherently provides the latching mechanism needed for read operations through their complementary configurations and threshold voltage differences. This integration eliminates the need for separate dedicated latching circuits for each bit line, thereby reducing the overall circuit layout area while maintaining read operation capability.

The patent combines multiple functions into the differential PMOS transistor structure. The differential pair simultaneously provides storage functionality, read operation support, and latching mechanisms. By integrating these functions into the transistor pairs themselves rather than requiring separate dedicated circuits, the patent achieves higher array density while maintaining full read operation support.

The patent merges latching functionality directly into the differential PMOS pairs, eliminating the need for separate shared latching circuits. Each differential pair self-latches through its complementary transistor configurations and threshold voltage differences. This approach increases array density by reducing the number of separate latching circuit components while actually simplifying the overall circuit architecture by removing the need for additional shared latching infrastructure.