/ˈpiː mɪk/
n. — "DDR5 DIMM's built-in power butler stabilizing noisy rails."
PMIC (Power Management Integrated Circuit) on DDR5 DIMMs regulates motherboard 12V to clean 1.1V core/supply rails for DRAM, eliminating voltage droop during 8800MT/s burst writes where traditional schemes collapsed. Integrates buck converters, sequencing logic, and thermal monitoring per-DIMM, mocking DDR4's fragile discrete regulation while enabling 128GB+ densities at extreme speeds.
Key characteristics and concepts include:
- Multi-phase buck conversion delivering 1.1V core + 1.8V I/O rails with <1% droop during 100A transients.
- Integrated sequencing ensuring DRAM VDD before VDDQ, preventing latchup during power-on.
- Per-DIMM autonomy—each DIMM self-regulates regardless of channel neighbors.
- Telemetry reporting voltage/current/thermals via sideband bus for controller health monitoring.
In dual-channel DDR5 burst write, PMIC surges 200A across four DIMMs while maintaining VREF stability, preventing the eye closure that killed DDR4 at 3200MT/s.
An intuition anchor is to picture PMIC as DDR5's personal voltage bouncer: motherboard delivers dirty 12V street power, PMIC cleans it to precise 1.1V shots—keeping 8800MT/s data eyes crisp when transients would otherwise start bar fights.