AT24C256C-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	A0	input	Device address input, hard-wired to GND or VCC for device selection; if left undriven it is internally pulled down to GND, and Microchip recommends connecting it to a known state with a pull-up of 10 kΩ or less.
2	A1	input	Device address input, hard-wired to GND or VCC for device selection; if left undriven it is internally pulled down to GND, and Microchip recommends connecting it to a known state with a pull-up of 10 kΩ or less.
3	A2	input	Device address input, hard-wired to GND or VCC for device selection; if left undriven it is internally pulled down to GND, and Microchip recommends connecting it to a known state with a pull-up of 10 kΩ or less.
4	GND	power_in	Ground reference for the power supply, which should be connected to the system ground.
5	SDA	bidirectional	Open-drain bidirectional serial data pin that must be pulled high through an external pull-up resistor not exceeding 10 kΩ and may be wire-ORed with other open-drain devices on the bus.
6	SCL	input	Serial clock input that latches SDA data on its rising edge and must be forced high when the bus is idle or pulled high through an external pull-up resistor.
7	WP	input	Write-protect input: connection to GND allows normal write operations, connection to VCC inhibits writes to the full array, and if left floating it is internally pulled down to GND, so a known state with a pull-up of 10 kΩ or less is recommended.
8	VCC	power_in	Device power supply pin; operation at invalid VCC voltages may produce spurious results and should not be attempted.

Key specifications

Parameter	Value
Manufacturer	Microchip Tech
Package	TSSOP-8
Category	Memory
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	VCC1	1.7		5.5	V		9
Operating Temperature (Case), Industrial		-40		85	°C		9
Temperature under bias		-55		125	°C		9
Storage temperature		-65		150	°C		9
VCC power supply (absolute maximum)	VCC			6.25	V		9
Voltage on any pin with respect to ground		-1		7	V		9
DC output current				5	mA		9
ESD protection		4			kV		9
Supply Current (Read)	ICC1		1	2	mA	VCC = 5.0V, Read at 400 kHz	9
Supply Current (Write)	ICC2		2	3	mA	VCC = 5.0V, Write at 400 kHz	9
Standby Current	ISB1			1	µA	VCC = 1.7V, VIN = VCC or GND	9
Standby Current	ISB1			6	µA	VCC = 5.0V, VIN = VCC or GND	9
Input Leakage Current	ILI		0.1	3	µA	VIN = VCC or GND; VCC = 5.0V	9
Output Leakage Current	ILO		0.05	3	µA	VOUT = VCC or GND; VCC = 5.0V	9
Input Low Level	VIL	-0.6		0.3	V	Max is VCC x 0.3 (Note 2)	9
Input High Level	VIH	0.7		0.5	V	Min is VCC x 0.7; max is VCC + 0.5 (Note 2)	9
Output Low Level	VOL1			0.2	V	VCC = 1.7V, IOL = 0.15 mA	10
Output Low Level	VOL2			0.4	V	VCC = 3.0V, IOL = 2.1 mA	10
Clock Frequency, SCL	fSCL			400	kHz	1.7V	10
Clock Frequency, SCL	fSCL			1000	kHz	2.5V, 5.0V	10
Clock Pulse Width Low	tLOW	1300			ns	1.7V	10
Clock Pulse Width Low	tLOW	500			ns	2.5V, 5.0V	10
Clock Pulse Width High	tHIGH	600			ns	1.7V	10
Clock Pulse Width High	tHIGH	400			ns	2.5V, 5.0V	10
Noise Suppression Time	tI			100	ns	1.7V	10
Noise Suppression Time	tI			50	ns	2.5V, 5.0V	10
Clock Low to Data Out Valid	tAA	50		900	ns	1.7V	10
Clock Low to Data Out Valid	tAA	50		450	ns	2.5V, 5.0V	10
Bus Free Time between Stop and Start	tBUF	1300			ns	1.7V	10
Bus Free Time between Stop and Start	tBUF	500			ns	2.5V, 5.0V	10
Start Hold Time	tHD.STA	600			ns	1.7V	10
Start Hold Time	tHD.STA	250			ns	2.5V, 5.0V	10
Start Set-up Time	tSU.STA	600			ns	1.7V	10
Start Set-up Time	tSU.STA	250			ns	2.5V, 5.0V	10
Data In Hold Time	tHD.DAT	0			ns	1.7V	10
Data In Set-up Time	tSU.DAT	100			ns	1.7V	10
Inputs Rise Time	tR			300	ns	1.7V	10
Inputs Fall Time	tF			300	ns	1.7V	10
Inputs Fall Time	tF			100	ns	2.5V, 5.0V	10
Stop Set-up Time	tSU.STO	600			ns	1.7V	10
Stop Set-up Time	tSU.STO	250			ns	2.5V, 5.0V	10
Data Out Hold Time	tDH	50			ns	1.7V	10
Write Cycle Time	tWR			5	ms	1.7V	10
Time required after VCC is stable before the device can accept commands	tPUP	100			µs		11
Power-on Reset Threshold Voltage	VPOR			1.5	V		11
Minimum time at VCC = 0V between power cycles	tPOFF	500			ms		11
Input/Output Capacitance (SDA)	CI/O			8	pF	VI/O = 0V	12
Input Capacitance (A0, A1, A2 and SCL)	CIN			6	pF	VIN = 0V	12
Write Endurance		1e+06			write cycles	TA = 25°C, VCC = 3.3V, Page Write mode	12
Data Retention		100			years	TA = 55°C	12

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	8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC] © 2017 Microchip Technology Inc.	25

CAD (KiCad official)

Symbol: AT24C256C-XHL-B
Footprint: Package_SO:TSSOP-8_4.4x3mm_P0.65mm
3D model: TSSOP-8 (KiCad packages3D, STEP)
3D model files: at24c256c-xhl-b-etched.step / at24c256c-xhl-b-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); at24c256c-xhl-b.step / at24c256c-xhl-b.glb are the bare package body.

Provenance

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

Datasheet: Microchip Tech datasheet (39 pp, sha256 5887615de6328a65, retrieved 2026-11-05, 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

AT24C256C-XHL-B

Verified AT24C256C-XHL-B

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3D Model

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