microSD
Memory Cards · 7 specs
Direct Answer
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.
Source: SD Association (SDA) / SanDisk TransFlash Specification · Last reviewed Aug 28, 2026
Specs
| 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) |
| Operating Voltages | 2.7V–3.6V (Standard) / 1.8V (UHS-I signal) |
| Passive Adapter Compatibility | Electrically identical to full-size SD (100% pin-compatible via passive sleeve adapter) |
Mechanical Miniaturization and Passive Adaptability
Because microSD shares the identical electrical signalling and command protocol of standard SD cards (minus the mechanical write-protect switch and one redundant VSS ground pin, reducing the pin count from 9 to 8), a microSD card can be inserted into a passive plastic adapter shell and used in full-size SD camera slots with zero active silicon translation or latency penalty.
Mobile and Embedded Storage Dominance
microSD completely displaced competing ultra-compact formats (such as Sony's Memory Stick Micro M2 and Siemens' MMCmicro). With the advent of Application Performance Classes (A1 and A2), microSD cards are certified to handle random random-read/write IOPS necessary to run Android apps and operating systems directly from the card (such as on Raspberry Pi single-board computers and Nintendo Switch consoles).