ITPEC FE Morning October 2022 Question 22

SRAM and Flip-Flop Circuits — identify which memory type uses a flip-flop as its storage cell.

Memory cell technologies:
- SRAM — uses a flip-flop (latch) circuit made of 4–6 transistors per cell; no refresh needed → "static"
- DRAM — uses a capacitor + 1 transistor; charge leaks → requires periodic refresh → "dynamic"
- SDRAM — same capacitor-based cells as DRAM, but synchronized with the system clock
- EEPROM — uses a floating gate transistor to trap charge; non-volatile, electrically erasable

Why not others:
- (a) DRAM — capacitor-based, not flip-flop
- (b) EEPROM — floating gate transistor, non-volatile storage
- (c) SDRAM — variant of DRAM, still capacitor-based

Key rule: SRAM = flip-flop (fast, expensive, used for cache). DRAM = capacitor (dense, cheap, used for main memory).

AI-generated — may contain errors