AT25640B-XHL-B from Microchip Tech, in a TSSOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	CS	input	Chip Select: the device is selected when CS is low, and when it is not selected SI is not accepted and SO stays high-impedance.
2	SO	tri_state	Serial Data Output: remains in a high-impedance state when the device is not selected or after an invalid opcode until the next falling edge of CS.
3	WP	input	Write Protect: allows normal read/write when held high, and when held low with WPEN set to one all status register writes are inhibited.
4	GND	power_in	Ground reference for the device.
5	SI	input	Serial Data Input: data is accepted only while the device is selected, and inputs are ignored while SO is in the high-impedance state during HOLD.
6	SCK	input	Serial Data Clock: always an input, which makes the device operate as a slave; the device is specified up to 20 MHz at 5.0 V.
7	HOLD	input	HOLD: when brought low while SCK is low it pauses serial communication without resetting the sequence, and it resumes when brought high while SCK is low.
8	VCC	power_in	Power supply, specified from 1.8 V to 5.5 V.

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	TSSOP-8
Category	Interface ICs
Pins	8

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Supply Voltage (1.8V range)	VCC1	1.8		5.5	V		4
Supply Voltage (2.5V range)	VCC2	2.5		5.5	V		4
Supply Voltage (4.5V range)	VCC3	4.5		5.5	V		4
Supply Current, Read	ICC1		7.5	10	mA	VCC = 5.0V at 20MHz, SO = Open, Read	4
Supply Current, Read/Write	ICC2		4	10	mA	VCC = 5.0V at 20MHz, SO = Open, Read, Write	4
Supply Current, Read/Write at 5MHz	ICC3		4	6	mA	VCC = 5.0V at 5MHz, SO = Open, Read, Write	4
Standby Current	ISB1			6	μA	VCC = 1.8V, CS = VCC	4
Standby Current	ISB2		0.3	7	μA	VCC = 2.5V, CS = VCC	4
Standby Current	ISB3		2	10	μA	VCC = 5.0V, CS = VCC	4
Input Leakage	IIL	-3		3	μA	VIN = 0V to VCC	4
Output Leakage	IOL	-3		3	μA	VIN = 0V to VCC, TAC = 0°C to 70°C	4
Input Low-voltage	VIL	-0.6			V		4
Output Low-voltage (3.6V ≤ VCC ≤ 5.5V)	VOL1			0.4	V	3.6V ≤ VCC ≤ 5.5V, IOL = 3.0mA	4
Output Low-voltage (1.8V ≤ VCC ≤ 3.6V)	VOL2			0.2	V	1.8V ≤ VCC ≤ 3.6V, IOL = 0.15mA	4
Output Capacitance (SO)	COUT			8	pF	VOUT = 0V; TA = 25C, f = 1.0MHz, VCC = 5.0V	4
Input Capacitance (CS, SCK, SI, WP, HOLD)	CIN			6	pF	VIN = 0V; TA = 25C, f = 1.0MHz, VCC = 5.0V	4
SCK Clock Frequency	fSCK	0		5	MHz	VCC = 1.8V to 5.5V	5
Input Rise Time	tRI			2	μs	VCC = 1.8V to 5.5V	5
Input Fall Time	tFI			2	μs	VCC = 1.8V to 5.5V	5
SCK High Time	tWH	80			ns	VCC = 1.8V to 5.5V	5
SCK Low Time	tWL	80			ns	VCC = 1.8V to 5.5V	5
CS High Time	tCS	100			ns	VCC = 1.8V to 5.5V	5
CS Setup Time	tCSS	100			ns	VCC = 1.8V to 5.5V	5
CS Hold Time	tCSH	100			ns	VCC = 1.8V to 5.5V	5
Data In Setup Time	tSU	20			ns	VCC = 1.8V to 5.5V	5
Data In Hold Time	tH	20			ns	VCC = 1.8V to 5.5V	5
HOLD Setup Time	tHD	20			ns	VCC = 1.8V to 5.5V	5
HOLD Hold Time	tCD	20			ns	VCC = 1.8V to 5.5V	5
Output Valid	tV			80	ns	VCC = 1.8V to 5.5V	5
Output Hold Time	tHO	0			ns	VCC = 1.8V to 5.5V	5
HOLD to Output Low Z	tLZ	0		100	ns	VCC = 1.8V to 5.5V	6
HOLD to Output High Z	tHZ			200	ns	VCC = 1.8V to 5.5V	6
Output Disable Time	tDIS			200	ns	VCC = 1.8V to 5.5V	6
Write Cycle Time	tWC			5	ms	VCC = 1.8V to 5.5V	6
Operating Temperature		-55		125	C		2
Storage Temperature		-65		150	C		2
Voltage on Any Pin with Respect to Ground		-1		7	V		2
Maximum Operating Voltage				6.25	V		2
DC Output Current				5	mA		2
Recommended Operating Temperature (Industrial)	TAI	-40		85	°C	VCC = 1.8V to 5.5V	4

Materials and finish

As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).

Part	Material	Colour / plating	Datasheet says	Page
contacts		tin	U = Green, Matte Sn Lead Finish	14

CAD (KiCad official)

Symbol: AT25640B-XHL-B
Footprint: Package_SO:TSSOP-8_4.4x3mm_P0.65mm
3D model: TSSOP-8 (KiCad packages3D, STEP)
3D model files: at25640b-xhl-b-etched.step / at25640b-xhl-b-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); at25640b-xhl-b.step / at25640b-xhl-b.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (23 pp, sha256 6eb63f39b2e61b60, retrieved 2026-11-06, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

AT25640B-XHL-B

Verified AT25640B-XHL-B

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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