Power management

PMIC (Power Management IC)

Multiple rails, sequencing, supervision, and protection in one integrated chip.

What is it?

A PMIC integrates multiple regulators (bucks + LDOs), sequencing logic, supervisors, and protection circuits into a single chip. Used in systems with 3+ rails where discrete regulators would consume too much board space — automotive cameras, infotainment processors, network ASICs, etc. PMICs handle the boring orchestration (turn rails on/off in the right order, monitor for faults) so the system designer can focus on the application.

When do you need it?

  • Automotive camera modules requiring multiple regulated rails (CIS analog/digital, ISP core/IO).
  • Embedded SoC platforms needing 5+ rails with strict sequencing.
  • Communication modules where size and BOM count must be minimised.
  • Networking ASICs with on-the-fly voltage scaling.
  • Multi-channel sensor front-ends with precision rails.

How to pick the right one

Number and type of rails
Count bucks + LDOs + protection features needed. Most PMICs are spec'd to a target SoC.
Per-rail current capability
Match each integrated rail's IOUT spec to your load.
Sequencing flexibility
OTP (one-time-programmable) factory sequencing vs I²C runtime control. OTP is simpler/cheaper, I²C lets firmware adjust.
Functional safety / ASIL
For automotive: does the PMIC have FMEDA, ABIST, ISO 26262 documentation? Critical for ASIL-B+ applications.
Package and thermal
QFN sizes 3×3 to 5×5 mm common; thermal pad sizing matters for sustained full-load operation.

What Magnias offers

Magnias PMIC family targets automotive camera and similar multi-rail applications. Flagship MI8101B-N33 offers 3 synchronous bucks + 1 LDO in compact 3×3 mm QFN with e-Fuse OTP configuration, spread-spectrum + phase-shift + dither EMI suppression, AEC-Q100 Grade 1, and clean fast-transient performance for CIS camera modules.

Common questions

OTP or I²C configuration?
OTP: factory-programmed once, simpler BOM, lower cost. I²C: runtime-adjustable rails and protections, more flexible but adds firmware complexity. Most automotive cameras use OTP for predictability.
Does PMIC integration save board space?
Significantly — 4 rails in one 3×3 mm QFN replaces ~10 discrete components. Saves ~50-70% board area.
How does spread-spectrum reduce EMI?
Modulates the switching frequency over ±5-10% range, spreading the spectral peak across a band instead of a single line. Lowers peak emissions by 6-10 dB — usually the difference between passing and failing CISPR 25.
Is the MI8101B ASIL-rated?
MI8101B is AEC-Q100 Grade 1 qualified for general automotive use but doesn't carry ASIL-B safety certification on its own — pair with appropriate system-level safety design.