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Microchip Technology 93C66B-I/P — Memory (DRAM / SRAM / Flash / EEPROM)

Microchip 93C66B-I/P 4Kbit EEPROM, Microwire, 2 MHz, DIP-8

MPN93C66B-I/P
Active

Microchip 93C66B-I/P serial EEPROM, 4Kbit (256 x 16), Microwire interface, 2 MHz clock, 4.5V to 5.5V supply, -40°C to 85°C, 8-pin PDIP tube.

$0.4600Ref. price · indicative, final on quote
Microchip Technology 93C66B-I/P datasheet (PDF)
Packaging8-DIP (0.300", 7.62mm)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

93C66B-I/P specifications
ParameterValue
Memory typeNon-Volatile
MountingThrough Hole
Voltage4.5V ~ 5.5V
Frequency2 MHz
Memory interfaceMicrowire
Operating temperature-40°C~85°C(TA)
PackageTube
TechnologyEEPROM
Memory size4Kbit
Memory formatEEPROM
Case8-DIP (0.300\", 7.62mm)
Memory organization256 x 16
Write cycle time - word, page2ms

Product details

4Kbit serial EEPROM for calibration and configuration storage

The Microchip 93C66B-I/P is a 4Kbit serial EEPROM organized as 256 x 16 bits, communicating over a Microwire bus at up to 2 MHz.

Industrial temperature range and 5V-only operation

The 4.5V minimum supply means it cannot run from a 3.3V rail without a level translator — if your BOM is mixed-voltage, budget a 5V supply or a separate regulator for the EEPROM bus. The Microwire interface uses chip select (CS), serial clock (SK), and data in/out (DI/DO) lines; the 2 MHz clock rate gives about 250 kbytes/s read throughput, adequate for storing calibration tables, serial numbers, or boot configuration words.

Frequently asked questions

Is 93C66B-I/P compatible with 5V systems?

Yes. The supply voltage range is 4.5V to 5.5V, making it a native 5V-logic part. It is not 3.3V tolerant on the Microwire interface — if your host controller runs at 3.3V, you will need a level shifter or a separate 5V rail for the EEPROM.

What is the difference between 93C66B-I/P and 93C66B-I/SN?

The two parts share the same 4Kbit EEPROM die and electrical specifications. The difference is the package: -I/P is the 8-pin PDIP (through-hole), while -I/SN is the 8-pin SOIC (surface-mount). Choose the PDIP for socketed prototyping or through-hole assembly; choose the SOIC for automated SMT production.