microSD vs. MultiMediaCard (MMC)
Comparing 2 standards across 13 specifications. 13 key differences identified.
microSD (originally developed as TransFlash / T-Flash by SanDisk in 2004 and ratified by the SD Association in 2005) is the ultra-compact form factor of the Secure Digital family. Measuring 15.0 × 11.0 × 1.0 mm (approximately 20% the size of a standard SD card), it is the universal removable storage medium for smartphones, action cameras, drones, and handheld gaming consoles.
MultiMediaCard (MMC) is a solid-state memory card standard introduced in 1997 by Siemens and SanDisk based on a 7-pin serial bus. Evolving into RS-MMC and MMCmobile, it formed the physical and protocol foundation of both the SD card and JEDEC eMMC (embedded MultiMediaCard), the ubiquitous internal storage standard for mobile devices, smart TVs, and single-board computers.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Operating Voltages
|
2.7V–3.6V (Standard) / 1.8V (UHS-I signal) | 3.3V (standard) / 1.8V (dual voltage / eMMC) |
|
Governing Body
|
SD Association (SDA) | — |
|
Original Name
|
TransFlash (TF Card / T-Flash by SanDisk, 2004) | — |
|
Physical Dimensions
|
15.0 mm × 11.0 mm × 1.0 mm (Weight: ~0.25 g) | — |
|
Pin Configurations
|
8 pins (UHS-I / Legacy) / 16 pins (UHS-II dual-row) | — |
|
Capacity Standards
|
microSD (≤2GB), microSDHC (4–32GB), microSDXC (64GB–2TB), microSDUC (up to 128TB) | — |
|
Passive Adapter Compatibility
|
Electrically identical to full-size SD (100% pin-compatible via passive sleeve adapter) | — |
|
Governing Standards Bodies
|
— | MMCA (historically) / JEDEC (eMMC Standard JESD84-B51A) |
|
Introduction Year
|
— | 1997 (Siemens & SanDisk) |
|
Physical Dimensions (Full MMC)
|
— | 32.0 mm × 24.0 mm × 1.4 mm (7-pin interface) |
|
Reduced Size Formats
|
— | RS-MMC (24.0 × 18.0 × 1.4 mm), MMCmobile (dual voltage), MMCmicro (14.0 × 12.0 × 1.1 mm) |
|
Embedded Evolution
|
— | eMMC (eMMC 4.5, 5.0, 5.1 delivering up to 400 MB/s via 8-bit parallel bus in BGA packaging) |
|
Bus Widths
|
— | 1-bit (legacy MMC), 4-bit (MMC Plus), 8-bit (eMMC HS400) |