24LC41A

• Single supply with operation down to 2.5V
• Completely implements DDC1/DDC2 interface for monitor identification, including recovery to DDC1
• Improved noise immunity
• Separate high speed 2-wire bus for microcontroller access to 4K-bit Serial EEPROM
• Low-power CMOS technology
• 2 mA active current typical
• 20 A standby current typical at 5.5V
• Dual 2-wire serial interface bus, I2C™ compatible
• Hardware write-protect for Microcontroller Access Port
• Self-timed write cycle (including auto-erase)
• Page write buffer for up to 8 bytes (DDC port) or 16 bytes (4K Port)
• 100 kHz (2.5V) and 400 kHz (5V) compatibility
• 1,000,000 erase/write cycles
• Data retention > 40 years
• 8-pin PDIP package
• Available for extended temperature ranges
- Commercial (C): 0 to +70
- Industrial (I): -40 to +85

V_CC...........................................................................................................................................................6.5V
All inputs and outputs w.r.t. V_SS ...................................................................................... -0.6V to V_CC +1.0V
Storage temperature ..............................................................................................................65 to +150
Ambient temperature with power applied..............................................................................-65 to +125
ESD protection on all pins ..................................................................................................................................................... 4 kV
† NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to
the device. This is a stress rating only and functional operation of the device at those or any other conditions
above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating
conditions for extended periods may affect device reliability.

The Microchip Technology Inc. 24LC41A is a dual port 128 x 8 and 512 x 8-bit Electrically Erasable PROM (EEPROM). This device is designed for use in applications requiring storage and serial transmission of configuration and control information. Three modes of operation have been implemented:
• Transmit-only mode for the DDC Monitor Port
• Bidirectional mode for the DDC Monitor Port
• Bidirectional, industry-standard 2-wire bus for the
4K Microcontroller Access Port Upon power-up, the DDC Monitor Port will be in the Transmit-only mode, repeatedly sending a serial bit stream of the entire memory array contents, clocked by the VCLK pin. A valid high-to-low transition on the DSCL pin will cause 24LC41A to enter the transition mode, an look for a valid control byte on the I2C bus. If it detects a valid control byte from the master, it will switch to Bidirectional mode, with byte selectable read/ write capability of the memory array using DSCL. If no control byte is received, the device will revert to the Transmit-only mode after it received 128 consecutive VCLK Package Type pulses while the DSCL pin is idle.

The 4K-bit microcontroller port is completely independent of the DDC port, therefore, 24LC41A can be accessed continuously by a microcontroller without interrupting DDC transmission activity. The 24LC41A is available in a standard 8-pin PDIP package in both commercial and industrial temperature ranges.