Details

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BUY AT28C256-15JI https://www.utsource.net/itm/p/1035104.html
Octal Buffers/Drivers With 3-State Outputs 20-VQFN -40 to 85

Parameter	Value
Device Type	256K x 8-Bit CMOS EEPROM
Package Type	28-Pin SOJ (Small Outline J-Lead)
Operating Voltage (Vcc)	4.5V to 5.5V
Standby Current ( typical @ Vcc = 5V)	1 μA
Active Current ( typical @ Vcc = 5V)	20 mA
Write Cycle Time (typical @ Vcc = 5V)	5 ms
Data Retention	10 years
Endurance Cycles	1,000,000 cycles
Operating Temperature Range	-40°C to +85°C
Storage Temperature Range	-65°C to +150°C
Organization	32K x 8
Access Time (typical @ Vcc = 5V)	70 ns
Write Protect Pin	WP (Pin 1)
Chip Select Pin	CS (Pin 28)
Output Enable Pin	OE (Pin 27)
Write Enable Pin	WE (Pin 26)

Instructions for Use:

1. Power Supply:

   • Connect Vcc (Pin 28) to +5V.
   • Connect Vss (Pin 14) to GND.

2. Chip Select (CS):

   • Active Low. When CS is low, the device is selected and can be read from or written to.
   • When CS is high, the device is deselected and the outputs are high impedance.

3. Output Enable (OE):

   • Active Low. When OE is low and CS is also low, data is read from the device.
   • When OE is high, the outputs are high impedance.

4. Write Enable (WE):

   • Active Low. When WE is low and CS is also low, a write operation can occur if the address and data lines are stable.
   • When WE is high, the device is in read mode or idle state.

5. Write Protect (WP):

   • Active High. When WP is high, all write operations are inhibited.
   • When WP is low, write operations are allowed.

6. Address Lines (A0-A14):

   • These pins are used to select the memory location to be accessed.
   • A0 is the least significant bit, and A14 is the most significant bit.

7. Data Lines (D0-D7):

   • These pins are used for data input during write operations and data output during read operations.

8. Write Operation:

   • Set CS and WE low.
   • Apply the desired address to the address lines.
   • Apply the data to be written to the data lines.
   • Hold WE low for at least the minimum write pulse width.
   • Return WE high to complete the write cycle.

9. Read Operation:

   • Set CS and OE low.
   • Apply the desired address to the address lines.
   • The data from the selected memory location will appear on the data lines after the access time.

10. Data Retention:

    • Data will be retained for up to 10 years when the device is not powered.

11. Handling Precautions:

    • Handle the device with care to avoid static discharge.
    • Ensure proper power sequencing to prevent damage to the device.

12. Endurance:

    • The device can withstand up to 1,000,000 write cycles per memory location.

13. Temperature Considerations:

    • Operate the device within the specified temperature range to ensure reliable performance.

14. Storage:

    • Store the device in a dry, cool place to avoid damage from moisture and extreme temperatures.

(For reference only)