6t SRAM Cell Schematic

# The 6T Cell's Circuit, and the Butterfly Curve That Measures It

two cross-coupled inverters fighting over two nodes — read stability is literally the overlap area

THE 6T CELL — ACTUAL TOPOLOGY VDD GND PMOS-A NMOS-A Q PMOS-B NMOS-B Q̄ ACC-1 ACC-2 WL BL BL̄ 4 latch transistors cross-coupled + 2 access transistors gated by WL = six, total read: sense a BL/BL̄ voltage difference without disturbing Q/Q̄ write: external drivers overpower the latch's own feedback, past its switching threshold

No refresh, no destructive readout — SRAM trades a larger, always-leaky 6T cell for faster, more predictable access than DRAM's 1T1C cell.

That tradeoff is exactly what cache memory rewards and bulk main memory does not — which is why SRAM sits at L1/L2/L3, not in the DIMM slot.

THE BUTTERFLY CURVE — READ STABILITY, MEASURED two inverters' transfer curves, mirrored and overlaid V(Q) → V(Q̄) → inverter 1 inverter 2 SNM SNM the largest square that fits in each lobe = static noise margin bigger lobes, bigger squares, more margin against disturb during read at small geometries, transistor mismatch skews the two curves apart — lobes shrink unevenly

Three-way memory hierarchy, named not retold: DRAM 1T1C (dram_1968) · EPROM/EEPROM/NAND non-volatile · SRAM 6T (this series)

Take 6t sram cell schematic further

Ask the copilot about this term, or have our engineers assess it against your process.

Ask CFSGPT about this → Request a technical assessment → Open the CFS app