ATA5577M3 vs EM4205 / EM4305

Compare ATA5577M3 and EM4205/EM4305 125 kHz RFID chips. ATA5577M3 offers multi-format emulation with 330 bits user memory; EM4205/4305 provides 288 bits with ISO 11784/11785 compliance.

Side-by-side specs

Frequency

ATA5577M3: 125 kHz
EM4205 / EM4305: 125 kHz (100 to 150 kHz range)

Protocol

ATA5577M3: EM4100, EM4102, T5557, Hitag, Indala, and other LF formats
EM4205 / EM4305: ISO 11784 / 11785 Standard Compliant, compatible with EM4469/EM4569 communication protocol

Memory

ATA5577M3: 363 bits total (330 bits user programmable)
EM4205 / EM4305: 512 bit EEPROM organized in 16 words of 32 bit (288 bits user free in words 5-13), 32 bit unique identifier (UID), 32 bit password

Interface

ATA5577M3: RF (contactless)
EM4205 / EM4305: RF (contactless)

Temp Range

ATA5577M3: -40°C to +85°C
EM4205 / EM4305: -40°C to +85°C

Form Factor

ATA5577M3: Wafer, SO8, TSSOP8
EM4205 / EM4305: EMDFN02 (2.2 x 1.78 x 0.76 mm), EMDFN403 (1.1 x 1.4 x 0.46 mm), die/wafer form available

Security

ATA5577M3: 32-bit password protection for read/write operations
EM4205 / EM4305: 32 bit password read and write protection, lock feature converts EEPROM words into read-only

Spec	ATA5577M3	EM4205 / EM4305
Frequency	125 kHz	125 kHz (100 to 150 kHz range)
Protocol	EM4100, EM4102, T5557, Hitag, Indala, and other LF formats	ISO 11784 / 11785 Standard Compliant, compatible with EM4469/EM4569 communication protocol
Memory	363 bits total (330 bits user programmable)	512 bit EEPROM organized in 16 words of 32 bit (288 bits user free in words 5-13), 32 bit unique identifier (UID), 32 bit password
Interface	RF (contactless)	RF (contactless)
Temp Range	-40°C to +85°C	-40°C to +85°C
Form Factor	Wafer, SO8, TSSOP8	EMDFN02 (2.2 x 1.78 x 0.76 mm), EMDFN403 (1.1 x 1.4 x 0.46 mm), die/wafer form available
Security	32-bit password protection for read/write operations	32 bit password read and write protection, lock feature converts EEPROM words into read-only

Verdict

Choose ATA5577M3 if you need broad compatibility with legacy LF RFID systems across multiple formats including EM4100, EM4102, T5557, Hitag, and Indala. The chip provides 363 bits total memory with 330 bits user programmable and operates at the standard 125 kHz frequency. Its multi-protocol emulation capability makes it ideal for applications requiring cloning or compatibility with diverse existing reader infrastructure, such as access control retrofits, multi-vendor environments, or general-purpose credential applications. The 32-bit password protection secures both read and write operations, though it offers no permanent lock feature for converting memory to read-only status. Choose EM4205 or EM4305 if you require ISO 11784/11785 standard compliance for animal identification, pet tracking, or applications demanding formal standardization. These chips offer 512 bits total EEPROM (288 bits user-accessible in words 5-13, 32-bit UID, 32-bit password) and operate across a wider 100-150 kHz frequency range. The EM4205/4305 provides more structured memory organization with 16 words of 32 bits each and includes a lock feature that permanently converts EEPROM words to read-only mode, adding tamper-resistance for finalized credential data. The compatibility with EM4469/EM4569 communication protocols and unique identifier make these chips suitable for applications requiring device traceability and standards-compliant deployments where interoperability with ISO-certified readers is mandatory.

FAQ

What is the memory difference between ATA5577M3 and EM4205/EM4305?

ATA5577M3 provides 330 bits of user-programmable memory from 363 bits total. EM4205/EM4305 offers 288 bits user-accessible memory from 512 bits total EEPROM, plus a dedicated 32-bit UID and 32-bit password section.

Which chip supports more RFID protocols?

ATA5577M3 supports multiple LF formats including EM4100, EM4102, T5557, Hitag, and Indala through emulation. EM4205/EM4305 is ISO 11784/11785 compliant and compatible with EM4469/EM4569 protocols but does not emulate other formats.

Can either chip permanently lock memory to read-only?

EM4205/EM4305 includes a lock feature that permanently converts EEPROM words into read-only mode. ATA5577M3 offers 32-bit password protection for read/write operations but does not provide a permanent lock function.

Sourcing ATA5577M3 or EM4205 / EM4305 in volume?

Roxtron builds custom RFID and NFC products around both ATA5577M3 and EM4205 / EM4305. Tell us your project — quantities, form factor, timeline — and we'll come back within 24 hours with pricing and lead times.