AT25SF161B-SSHB-T from Dialog Semiconductor Adesto Adesto Technologies, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	CS#	input	Active-low chip select. Asserting CS# (low) selects the device; deasserting (high) puts it in standby. A high-to-low transition starts an operation; low-to-high ends it. A ~10 kΩ pull-up to VCC is recommended for correct power-up ramp.
2	SO/IO1	bidirectional	Serial data output in standard SPI; becomes bidirectional IO1 for Dual-SPI and Quad-SPI read/program commands. Data is clocked out on the falling edge of SCK. High-Z when CS# is deasserted.
3	WP#/IO2	bidirectional	Active-low hardware write protect for the Status Register when the Quad Enable (QE) bit is 0; becomes bidirectional IO2 when QE=1 for quad-SPI transfers. Internally pulled high - may be left floating if unused.
4	GND	power_in	Ground reference for the power supply. Connect to system ground.
5	SI/IO0	bidirectional	Serial data input in standard SPI (commands, addresses, write data), latched on the rising edge of SCK. Becomes bidirectional IO0 for Dual- and Quad-SPI read commands. Ignored when CS# is deasserted.
6	SCK	input	Serial clock input. Command, address, and input data on SI are latched on the rising edge; output data on SO is clocked out on the falling edge. Supports SPI modes 0 and 3 up to 108 MHz.
7	HOLD#/IO3	bidirectional	Active-low HOLD pin (pauses SPI transfer without resetting the clocking sequence) when QE=0; becomes bidirectional IO3 for quad-SPI transfers when QE=1. Internally pulled high - may be left floating if unused.
8	VCC	power_in	Device power supply. 2.7 V to 3.6 V for the -B (SSHB) grade. Add a decoupling capacitor near the pin.

Key specifications

Parameter	Value
Manufacturer	Dialog Semiconductor Adesto Adesto Technologies
Package	SOIC-8
Category	Memory
Pins	8

Ordering variants

AT25SF161B-SSHB-TSSHB-T
AT25SF161B-SSHB-TSSHB-B
AT25SF161B-SSHB-TSSHD-T
AT25SF161B-SSHB-TSSHD-B
AT25SF161B-SSHB-TSHB-T
AT25SF161B-SSHB-TSHB-B
AT25SF161B-SSHB-TSHD-T
AT25SF161B-SSHB-TSHD-B
AT25SF161B-SSHB-TMHB-T
AT25SF161B-SSHB-TMHD-T
AT25SF161B-SSHB-TUUB-T
AT25SF161B-SSHB-TUUD-T

CAD (KiCad official)

Symbol: AT25SF161B-SSHB-T
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Dialog Semiconductor Adesto Adesto Technologies datasheet (61 pp, sha256 619b98776bb02ba8, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF