UFS 3.1 devices require stable, clean power rails to prevent data corruption during high-speed reads and writes:
: Differential transmit pairs for data sent from the host to the UFS device.
For data recovery or forensic tasks, "ISP" refers to soldering directly to specific test points on a PCB rather than the full BGA grid. Common ISP connections for UFS 3.1 include: VCC & VCCQ TX0_P/N & RX0_P/N (Data Lane 0) Some UFS 3.1 implementations require a 10-ohm resistor
: The power supply for the UFS controller and I/O interface, usually 1.2V.
🔹 Most commonly a 153-ball BGA package, but pin mappings can vary slightly by manufacturer (Samsung, Kioxia, Micron, SK Hynix). Always cross-reference the specific datasheet! ufs 3.1 pinout
The traditional form factor, widely used in eMMC and adapted for early UFS.
(Note: Some early UFS implementations used a VCCQ rail for the controller and VCCQ2 for the PHY, but modern UFS 3.1 BGA packages generally consolidate these into the standard VCC and VCCQ2 configuration.)
The M-PHY employs two differential signaling modes:
UFS 3.1 | Universal Flash Storage | Samsung Semiconductor Global 🔹 Most commonly a 153-ball BGA package, but
| Ball | Signal | Type | Description | |------|--------|------|-------------| | A1 | VCC | Power | NAND flash core power (2.5V - 3.6V, typically 3.3V) | | A2 | VCC | Power | Same as A1 – connect together | | A4 | REF_CLK | Input | Reference clock (26 MHz typical, 19.2 / 38.4 MHz possible) | | A5 | RST_N | Input | Hardware reset (active low, internal pull-up) | | B1 | VCC | Power | NAND core power | | B2 | VCC | Power | NAND core power | | B3 | C/D | Input | Configuration / Boot mode. Pull high (VCCQ) for normal boot, low for test modes. | | B4 | VSS | Ground | Ground | | B5 | VSS | Ground | Ground | | C1 | VCCQ | Power | Controller I/O & logic (1.14V - 1.26V typical 1.2V) | | C2 | VCCQ | Power | Same as C1 | | C3 | D0_RX | Input | Lane 0 – Receiver differential input (from host) | | C4 | D0_TX | Output | Lane 0 – Transmitter differential output (to host) | | D3 | D1_RX | Input | Lane 1 – Receiver differential input | | D4 | D1_TX | Output | Lane 1 – Transmitter differential output | | D5 | VSS | Ground | Ground | | E1 | VCCQ2 | Power | Optional second I/O supply (1.8V or 2.5V). If unused, tie to VCCQ or leave NC. | | ... (center balls omitted) | ... | ... | Most balls in rows E–J / cols 3–10 are reserved or not connected | | L2 | VSS | Ground | Ground | | M1 | VSS | Ground | Ground |
Unlike the parallel interface used in older eMMC standards, UFS 3.1 utilizes a based on the MIPI M-PHY and UniPro specifications. This design choice allows for a significantly lower pin count , which simplifies PCB routing and reduces the physical footprint on space-constrained mobile motherboards.
For hardware engineers integrating UFS 3.1 into a new design, several key factors must be managed to ensure a robust and reliable system.
💡 If you are doing board rework, check the CMD and RST_N lines first if the device isn't enumerating. (Note: Some early UFS implementations used a VCCQ
A well‑executed UFS 3.1 layout will serve as a solid foundation for the next generation of storage.
JEDEC Publishes Update to Universal Flash Storage (UFS) Standard 30 Jan 2020 —
UFS 3.1 is engineered for extreme power efficiency, often requiring up to 83% less power during active use than traditional SSDs. 153-Ball Automotive UFS Memory - Mouser Electronics
UFS 4.0 was ratified by JEDEC in 2022, offering double the bandwidth of UFS 3.1 and continuing the trend of ever‑higher performance. However, the BGA153 footprint is expected to remain for compatibility reasons. Many of the layout guidelines presented here will still apply, albeit with stricter requirements on signal integrity and power distribution.
Its expanded capacity and enhanced endurance support diverse automotive workloads. * Interface. G4 2Lane. * Package Size. 11.5x13. samsung.com UNIVERSAL FLASH STORAGE (UFS 3.1) - Mouser Electronics
Differential output signals from host view (DIN for device). Receive Pairs