Note: While many manufacturers use the JEDEC standard 153-ball layout, always consult the specific datasheet (e.g., Kioxia or Kingston) for the exact model number. 2.1 Essential Signal Pins (M-PHY)
The Universal Flash Storage (UFS) standard has rapidly become the backbone of high-performance mobile computing. From flagship smartphones like the Samsung Galaxy S23 to automotive infotainment systems and professional drones, UFS 3.1 offers sequential read speeds exceeding 2,100 MB/s—dwarfing the capabilities of eMMC.
Route the differential pairs ( DIN and DOUT ) as short and direct as possible from the host processor to the storage BGA pads. ufs 3.1 pinout
Mechanically yes, electrically maybe, functionally rarely.
| 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 | Note: While many manufacturers use the JEDEC standard
The positive and negative traces of each differential pair must be perfectly length-matched to avoid phase skew, which corrupts the high-speed serial data stream.
* * Use open-source hardware databases (e.g., from Pine64 or Raspberry Pi CM4 carrier boards) or schematics of older flagship phones (Google Pixel 6, OnePlus 9) which often leak detailed UFS pinouts. Route the differential pairs ( DIN and DOUT
The following rules are distilled from application notes and SoC design manuals:
A critical signal that must be present before requesting power mode changes into Fast_Mode. Hardware Reset (RST_N): Used to reset the UFS device to its initial state. Power Rail Requirements
At the core of UFS 3.1's high-speed capability is the MIPI M-PHY physical layer. This layer uses to transmit and receive data over dedicated differential pairs. These pairs are designed to be highly immune to noise and electromagnetic interference, ensuring signal integrity even in the congested environment of a smartphone motherboard. The data signals are divided into:
| Rail | Voltage | Ripple max | Typical current (active) | Purpose | |------|---------|------------|--------------------------|---------| | | 2.5V – 3.6V | 100 mV | Up to 1.5A | NAND flash core | | VCCQ | 1.14V – 1.26V | 50 mV | 200-400 mA | Controller logic & UniPro PHY | | VCCQ2 | 1.7V – 1.95V or NC | 50 mV | ~100 mA | Optional for 1.8V I/O (e.g., UFS-to-host sideband) |